Question: A 64-year-old man presents to the emergency room with a headache and nausea. He reports that he was rocking his grandson to sleep when the symptoms began. He states the pain is constant and is primarily located on his right side. When asked to indicate the area of pain, he says that it surrounds his eye and upper forehead. He had one episode of vomiting. The patient also reports difficulty seeing out of his right eye, which he attributes to excessive tearing. The patient’s past medical history is significant for hypertension. His medications include hydrochlorothiazide. His temperature is 98.6°F (37°C), blood pressure is 135/91 mmHg, pulse is 72/min, and respirations are 12/min. The patient’s right eye is shown in Figure A. Upon physical examination, the right pupil is minimally responsive to light and the globe feels firm. A right-sided carotid bruit is appreciated. Which of the following is the most appropriate prophylaxis for this patient’s condition?

Answer: Acetazolamide

Explanation:
This patient is presenting with sudden-onset unilateral vision loss and an orbitofrontal headache with a dilated pupil and a hard ocular globe suggesting a diagnosis of acute angle-closure glaucoma. Long-term management of angle-closure glaucoma can include acetazolamide.

Examination of the eye in a patient with acute-closure glaucoma will reveal a red eye that is rock-hard and a mid-dilated pupil which is minimally reactive to light. The fundoscopic exam will show an increased optic cup-to-disk ratio (>0.4) and tonometry will show increased intraocular pressure. Gonioscopy is the diagnostic gold standard. Acute treatment and long-term management involve the administration of beta-blockers, alpha-2-agonists, and carbonic anhydrase inhibitors such as acetazolamide to decrease intraocular pressure. The definitive treatment is iridotomy.

Airaksinen et al. review the treatment of closed-angle glaucoma. They discuss how a combination of acetazolamide and beta-blockers can terminate an attack. They recommend using 1 drop of pilocarpine 3 hours after intravenous acetazolamide administration.

Figure/Illustration A is a clinical photograph showing an eye with injected conjunctiva (red circles) and a mid-dilated pupil. These findings are consistent with angle-closure glaucoma.

Incorrect Answers:
Answer B: Amitriptyline can be used as prophylaxis for migraines. Migraines present as unilateral, pulsating headaches that may be associated with nausea or photophobia. Patients with migraines can sometimes experience an aura with visual field changes; however, they would not have exam findings of a rock-hard eye or injection.

Answer C: Clopidogrel may be used as a conservative treatment for carotid atherosclerosis, which can be an embolic source for central retinal artery occlusion (CRAO). CRAO presents as acute, painless, monocular vision loss. A fundoscopic exam will demonstrate ischemia of the retina.

Answer D: Epinephrine is contraindicated in the treatment of angle-closure glaucoma as it increases pupillary dilation. It is used in the management of open-angle glaucoma. This would present with gradually patchy loss of vision and is generally painless.

Answer E: Verapamil is used as prophylaxis for cluster headaches. Cluster headaches present as unilateral, repetitive, brief headaches associated with severe peri-orbital pain, lacrimation, rhinorrhea, and Horner syndrome (miosis, ptosis, and anhidrosis).

Bullet Summary:
Pharmacologic management of acute angle-closure glaucoma involves beta-blockers, alpha-2 agonists, and carbonic anhydrase inhibitors.


Question: A 59-year-old woman comes to the clinic due to a 3-month history of “always feeling the urge to urinate” as well as vaginal pruritis. She states that she has had involuntary loss of urine about 4 times each day over the past 3 months. It is not associated with coughing or sneezing. Menopause occurred at age 52. She has a history of chlamydial infection in her 20's and has had 3 urinary tract infections over the past year. The patient has not been sexually active with her husband due to pain with intercourse. She has no other significant medical history and does not take any medications. Her temperature is 98.6°F (37.0°C), blood pressure is 115/70 mmHg, pulse is 70/min, and respirations are 12/min. On physical examination, the vulvar skin is pale and atrophic with reduced elasticity and multiple areas of petechiae. The vaginal mucosa also has a loss of rugae and several areas of friable irritation. There is minimal clear vaginal discharge. Urinalysis is normal and fecal occult blood test is negative. Pelvic ultrasound reveals a small, retroverted uterus. Which of the following is the most appropriate next step in management?

Answer: Vaginal moisturizers

Explanation:
This postmenopausal patient is presenting with vulvovaginal dryness and irritation, dyspareunia, urinary incontinence, and recurrent urinary tract infections, likely due to genitourinary syndrome of menopause (GSM). The most appropriate initial treatment is symptomatic relief with vaginal moisturizers and lubricants.

Reduced estrogen levels after menopause lead to vulvovaginal atrophy by causing reduced blood flow and collagen content in vulvovaginal tissues. Patients typically have thin vulvar skin and loss of vaginal tissue pliability. The bladder and urethral epithelium may also atrophy leading to dysuria and urinary frequency. Atrophic tissue becomes thin, dry, and susceptible to injury. The first line of treatment is vaginal moisturizers and lubricants. If this does not improve symptoms, the next step in treatment is vaginal estrogen to help restore blood flow in vulvovaginal tissues. Finally, hormone replacement therapy is indicated if symptoms are refractory to all other modalities.

Bhupathiraju et al. studied the association between vaginal estrogen and chronic disease risk. The authors found no association between low-dose vaginal estrogen and cardiovascular disease, cancer, and hip fractures over an 18-year period. The authors recommended that low-dose vaginal estrogen can be used indefinitely without concomitant progestin therapy.

Incorrect Answers:
Answer A: Metronidazole is the treatment for trichomoniasis or bacterial vaginosis. While patients with trichomoniasis can present with cervical petechiae and punctate hemorrhages, they typically also have frothy green discharge (absent in this patient). While patients with bacterial vaginosis can also have vaginal discharge, the discharge is typically malodorous and symptoms of pruritis are generally absent.

Answer B: Nitrofurantoin is the treatment of choice for urinary tract infections. While this patient has increased urinary frequency and a history of recurrent urinary tract infections, her normal urinalysis makes the diagnosis of urinary tract infection unlikely.

Answer C: Topical clobetasol cream is the treatment for lichen sclerosis. While lichen sclerosis can present with pain with intercourse and vulvar pruritis, patients often have plaques that disrupt the normal vulvar architecture. Lichen sclerosis does not affect the vaginal tissues.

Answer D: Topical estrogen is the treatment of choice for cases of vulvovaginal atrophy resistant to treatment with vaginal moisturizers and lubricants. This patient should first be trialed on vaginal moisturizers and lubricants.

Bullet Summary:
Vulvovaginal atrophy is initially treated with vaginal moisturizers and lubricants.


Question:
A 31-year-old man presents to clinic for evaluation of a 3-year history of infertility. He has no significant medical history and takes no medications. He exercises twice a day, often with heavy weightlifting, and eats a high-protein diet. He reports occasional alcohol use and remote marijuana use. His temperature is 99.5°F (37.5°C), blood pressure is 148/90 mmHg, pulse is 84/min, and respirations are 15/min. He is sexually active with his wife and has no history of sexually transmitted infections. Physical exam reveals small testes and a receding hairline. He also has palpable tissue underneath his nipples bilaterally. His muscle tone is normal in his upper and lower extremities bilaterally. His laboratory values are below:

Serum:
Creatinine: 1.3 mg/dL
Glucose: 110 mg/dL
Total bilirubin: 0.8 mg/dL
Aspartate aminotransferase (AST, GOT): 410 U/L
Alanine aminotransferase (ALT, GPT): 275 U/L

Hemoglobin: 12 g/dL
Leukocyte count: 5,300/mm^3
Platelet count: 250,000/mm^3

Which of the following is the most likely cause of this patient’s infertility?

Answer: Anabolic steroid use

Explanation:
This patient with infertility is presenting with decreased testicular size, receding hairline, gynecomastia (palpable breast tissue), and transaminitis. This is most likely due to exogenous testosterone from anabolic (androgenic) steroid use.

Young people (especially athletes and heavy weightlifters) looking to improve their physical performance may rely on the use of anabolic steroids (testosterone, boldenone, and stanozolol). These steroids adversely impair endogenous testicular function, causing infertility secondary to decreased testicular size and sperm count. Furthermore, hepatic dysfunction and cardiac dysfunction can occur at high doses. Excess testosterone is converted to estradiol, leading to breast enlargement and signs of gynecomastia. Aggression and mood disturbances may also occur in patients with excessive anabolic steroid use. Finally, skin findings of anabolic steroid use include accelerated male pattern baldness and acne. Patients should be counseled on avoiding these agents.

Van Wagoner et al. study the chemical composition of products marketed as selective androgen receptor modulators (SARMs). The authors find that less than half of the analyzed products contained compounds in the amount listed on the label. The authors recommend that clinicians counsel athletes and bodybuilders that these products are often mislabeled, are not regulated, and have not been shown to be safe or effective.

Incorrect Answers:
Answer B: Cryptorchidism is the failure of testicular descent into the scrotum and typically manifests in infancy. While uncorrected cryptorchidism can be a cause of infertility, this is an unlikely diagnosis in a man with palpable testes. Furthermore, cryptorchidism would not explain this patient’s receding hairline or gynecomastia.

Answer C: Excess growth hormone use should be suspected because growth hormone can be taken exogenously to improve athletic performance and can present with hypertension. This typically also presents with hyperglycemia and enlarged hands and feet.

Answer D: Klinefelter syndrome is an inherited disorder that also presents with infertility, gynecomastia, and decreased testicular size. This disorder also causes mental impairment and would not explain the patient’s elevated aminotransferases.

Answer E: Myotonic dystrophy is a multi-system disorder that can also present with testicular atrophy, reduced fertility, and hair loss. Patients with myotonic dystrophy also have widespread muscular atrophy and weakness, as well as clinical features of myotonia (e.g., difficulty releasing a handshake).

Bullet Summary:
Anabolic steroid use in men can cause reduced fertility by suppressing endogenous testosterone activity, and presents with gynecomastia, testicular atrophy, accelerated male balding patterns, and hepatotoxicity.


Question: A 24-year-old man presents to his primary care physician with left groin pain. The pain started a year ago and has progressed. He now has 8/10 pain when climbing stairs or rising from a seated position. He localizes the pain to the front of his groin. He denies any erythema or swelling. He has a history of hypertension, sickle cell anemia, and a splenectomy. He drinks a glass of wine with dinner every night and took up scuba diving 2 months ago but otherwise does not exercise. His temperature is 97.5°F (36.4°C), blood pressure is 124/68 mmHg, pulse is 82/min, and respirations are 16/min. His body mass index (BMI) is 18.1 kg/m^2. Physical exam reveals left groin pain at the terminal ranges of hip abduction and internal rotation. There is no point tenderness. A radiograph is obtained as in Figure A. Which of the following components of this patient’s history most strongly predisposed him to this condition?

Answer: History of sickle cell disease

Explanation:
This patient with sickle cell disease (SCD) presents with anterior groin pain, especially with weight-bearing, and radiographic findings of amorphous lytic and sclerotic lesions of the femoral head, consistent with avascular necrosis. SCD is a predisposing factor for avascular necrosis.

Avascular necrosis has a multitude of direct causes, including irradiation, trauma (history of femoral neck fracture), hematologic diseases such as leukemia, SCD, and idiopathic etiology. In traumatic causes, injury to the medial femoral circumflex artery supplying the femoral head causes vascular disruption with resulting osteonecrosis. In SCD, the propensity for sickle-shaped erythrocytes to stick to one another and occlude blood vessels results in loss of circulation to the femoral head with consequent osteonecrosis. Avascular necrosis of the femoral head presents with insidious onset of anterior groin pain. The diagnosis can be secured with plain radiographs, although magnetic resonance imaging has the highest sensitivity and specificity for uncertain cases. Treatment consists of bisphosphonates with crutches (non-weight-bearing) and/or surgery depending on the degree of femoral head collapse and etiology.

Akinyoola et al. studied the risk factors associated with avascular necrosis of the femoral head in patients with sickle cell disease. The authors found that the rate of pain crises and annual hospitalizations are associated with avascular necrosis. The authors recommend further study to explain differences in the prevalence of osteonecrosis in different populations with sickle cell disease.

Figure/Illustration A shows a plain radiograph of the left hip in a skeletally mature individual, demonstrating amorphous cortical lesions (red arrows) in the femoral head and cortical irregularity (blue arrow) typical of avascular necrosis.

Incorrect Answers:
Answer A: Excess alcohol use has been associated with the risk of avascular necrosis. This patient uses alcohol in moderation (2 drinks or fewer per day for men) and has no history of alcohol use disorder.

Answer C: Lack of physical activity is a predisposing factor for osteoporosis but is not associated with avascular necrosis. Osteoporosis may increase the risk of a hip fracture, which would present with a painful, shortened, and externally rotated lower extremity.

Answer D: Low BMI is not a predisposing factor for avascular necrosis. In contrast, obesity has been associated with an increased risk of avascular necrosis.

Answer E: Scuba diving can indirectly predispose patients to avascular necrosis through decompression sickness (Caisson Disease). In decompression, dissolved gases in the arterial supply form gas emboli, leading to microvascular occlusion and dysbaric osteonecrosis. However, this patient’s symptoms have been present for 1 year whereas he only recently began scuba diving.

Bullet Summary:
Sickle cell disease is a predisposing factor for avascular necrosis of the femoral head, which presents as insidious anterior groin pain.


Question:
A 26-year-old man presents to his primary care physician with a 6-month history of increasing lower back pain. He first felt the pain while lifting boxes at work but thought that he had just strained a muscle. The pain appears to be worse in the mornings and after rest. Exercise and physical activity appear to temporarily make the pain better. He has taken acetaminophen and ibuprofen for the pain. He has no significant medical history and takes no medications. His temperature is 98.6°F (37.0°C), blood pressure is 115/70 mmHg, pulse is 70/min, and respirations are 12/min. On physical exam, he is found to have limited flexion and extension of his spine as well as tenderness to palpation over the insertion of his patellar tendons bilaterally. Results from laboratory tests are shown below:

Serum:
Erythrocyte sedimentation rate (ESR): 61 mm/hr
C-reactive protein (CRP): 36 mg/L (normal <10 mg/L)

Which of the following is the most accurate test for this patient's condition?

Answer: Magnetic resonance imaging

Explanation:
This young man presents with low back pain that is relieved by physical activity, decreased spinal mobility, enthesitis of his patellar tendons, and elevated ESR/CRP values most likely has ankylosing spondylitis (AS). The most accurate diagnostic test for early ankylosing spondylitis is MRI.

Multiple imaging tests can diagnose ankylosing spondylitis. Radiographs of the spine will show squaring of vertebrae with vertical or marginal syndesmophytes resulting in a "bamboo spine" appearance. The earliest radiographic sign is the erosion of the iliac side of the sacroiliac joint, but this finding is not sensitive in the early stages of the disease. MRI is sensitive in detecting sacroiliac inflammation, which makes this the best modality for early detection of ankylosing spondylitis in young patients. Initial therapy for ankylosing spondylitis includes lifestyle modifications (exercise, smoking cessation, physical therapy) and non-steroidal anti-inflammatory drugs (NSAIDs). Therapy for patients with inadequate response to NSAIDs includes tumor necrosis factor inhibitors (etanercept, infliximab, adalimumab) and interleukin 17 inhibitors (secukinumab, ixekizumab).

Jung et al. studied whether signs of inflammation on MRI are correlated with bone quality in patients with ankylosing spondylitis. The authors find that bone marrow edema is negatively correlated with the trabecular bone score. The authors recommend control of active bone inflammation to prevent osteoporosis in patients with ankylosing spondylitis.

Incorrect Answers:
Answer A: Bone scan will show inflammation in the sacroiliac joints, but this study lacks specificity for this disease compared with other inflammatory forms of arthritis.

Answer B: CT will show bony changes but not active inflammation, so it is most commonly used to diagnose cervical fractures in patients with ankylosing spondylitis. While it can support the diagnosis, it is less accurate than an MRI.

Answer D: Radiographs will show erosion of the iliac side of the sacroiliac joint, but this finding is not sensitive in the early stages of the disease when bony ankylosis has not yet occurred. Radiographs may be an appropriate initial test.

Answer E: Ultrasound is useful in evaluating muscle strains or tendon tears; however, it is not able to detect bony abnormalities and is therefore of limited use in ankylosing spondylitis.

Bullet Summary:
MRI is the most sensitive and accurate test for the early detection of ankylosing spondylitis.


Question: A 15-month-old boy presents with his mother for his well-child exam. His mother is concerned about his vision, as she noticed him squinting while watching television. The patient was born at 39 weeks of gestation via spontaneous vaginal delivery. He is up to date with routine vaccinations. He is able to walk alone, speak 3 words, and scribble with a crayon. His temperature is 98.6°F (37.0°C), blood pressure is 80/55 mmHg, pulse is 105/min, and respirations are 25/min. On exam, his pupils are round and reactive to light. A photograph of his eyes is shown in Figure A. When focusing on the pediatrician's penlight, the patient's left eye wanders. However, when the right eye is covered, the left eye refocuses on the light. The rest of his neurological exam, including extraocular movements, is within normal limits. Which of the following is the most appropriate next step in management for this patient?

Answer: Patch the right eye

Explanation:
This patient, with a history that suggests decreased visual acuity, a positive cover test (refixation of the misaligned eye upon covering the appropriately aligned eye), and an asymmetric corneal light reflex in Figure A, is presenting with strabismus. Of the answer choices, only patching the sound eye (right eye) is an appropriate treatment.

Strabismus occurs when a patient's eyes are not aligned properly. It often presents in children with one or both eyes turning inward, outward, upward, or downward. Patients will often tilt their heads or squint their eyes to correct this misalignment. Without proper treatment, there is a significant risk of developing amblyopia. Amblyopia is a developmental disorder in the visual cortex caused by abnormal visual stimuli. Untreated strabismus is the most common cause of amblyopia; it is secondary to visual loss from the deviated eye. The treatment of choice is wearing an eye patch over the appropriately tracking eye (sound eye), thereby encouraging the use of the deviated eye and preventing vision loss in this eye. Other treatments include surgical correction of strabismus, pharmacological penalization of the sound eye with atropine, and dichoptic movies and video games.

Gopal et al. discuss the pathophysiology, prevention, and therapy for amblyopia as it relates to strabismus. The authors find that the earlier clinically refractive error and strabismus are detected and treated, the greater the likelihood of preventing amblyopia. The authors recommend treating amblyopia with the correction of refractive errors, patching, and pharmacologic treatments.

Figure/Illustration A shows displacement of the light reflex from the center of the pupil in this patient's right eye, as indicated by the black arrow. This is known as an asymmetric corneal light reflex and is seen in strabismus.

Incorrect Answers:
Answer A: Brain MRI is part of the initial workup for retinoblastoma. Retinoblastoma typically presents in early childhood with visual loss, leukocoria, and an abnormal red reflex, which this patient does not have.

Answer B: Head CT in a pediatric patient could be used to rule out hemorrhage following blunt head trauma. This patient has not experienced head trauma and has no symptoms of traumatic brain injury (abnormal neurologic exam, loss of consciousness seizures). CT scans are not preferred in pediatric patients to avoid radiation exposure.

Answer C: Patching the left eye (the inappropriately tracking eye) would not treat this patient's strabismus and would likely increase his risk for amblyopia due to further decreasing his visual stimuli in this eye.

Answer E: The Bielschowsky head tilt test is used to help diagnose trochlear nerve (CN IV) palsy. Patients with a unilateral trochlear nerve and subsequent superior oblique palsy experience double vision when tilting their head to one side, which is improved by tilting the head towards the shoulder on the unaffected side. A trochlear nerve palsy typically presents with difficulty looking down and a head tilt away from the side of the lesion, unlike this patient who appears to have a visual acuity deficit.

Bullet Summary:
Patching the appropriately aligned eye is the treatment of choice for strabismus to prevent progression to amblyopia.


Question: A 52-year-old man presents to the clinic with a left foot ulcer that he noticed 6 days ago. He has a history of obesity, hypertension, type 2 diabetes mellitus, and depression. His current medications include metformin, aspirin, rosuvastatin, lisinopril, and fluoxetine. He has a 25-pack-year smoking history and drinks 1 glass of wine a day. His temperature is 98.6°F (37.0°C), blood pressure is 115/70 mmHg, pulse is 70/min, and respirations are 12/min. On physical exam, he has a 1.2 x 1.7 cm ulcer on the plantar surface of his left metatarsal head. Which of the following tests will most appropriately assess this patient’s future risk of foot ulcers?

Contrast-enhanced foot magnetic resonance imaging

Answer: Monofilament testing

Explanation:
This patient with a history of diabetes, hypertension, and obesity now presenting with a foot ulcer most likely has a diabetic foot ulcer. He should undergo monofilament testing to assess the subsequent risk of developing foot ulcers.

Diabetic neuropathy is the most common underlying cause of diabetic foot ulcers. The pathophysiology of diabetic foot ulcers is thought to be the loss of pain and pressure sensation, which leads to muscular imbalance and foot deformities. This subsequently decreases microcirculation and impairs the integrity of the skin, leading to the formation of foot ulcers. Diabetic foot ulcers, like other neuropathic ulcers, occur commonly under bony prominences in the foot. During monofilament testing, a 10-g monofilament is placed on the plantar surface of the foot at a right angle, and pressure is applied until the patient can no longer tolerate it or the filament buckles. Patients with diabetic neuropathy have a higher-pressure threshold due to loss of sensation, and this is a useful predictor of the severity of diabetic neuropathy and future foot ulcer formation. The management of diabetic neuropathy consists of tight glycemic control, weight loss, blood pressure control, exercise, preventing complications, and pain management with pharmacotherapy (serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, or gabapentinoid antiseizure medications).

Tesfaye et al. study the efficacy of various first-line medications for diabetic nephropathy including amitriptyline, duloxetine, pregabalin, or gabapentin. The authors found that there were no differences between any of the medications as monotherapy. The authors recommended adding combination pharmacotherapy for patients with painful diabetic neuropathy that do not respond to initial monotherapy.

Incorrect Answers:
Answer A: Ankle-brachial index is a calculation made in the assessment of peripheral arterial disease (PAD). While PAD can present with arterial ulcers, these are usually located at the tip of the toes and not the plantar surface. Furthermore, the ankle-brachial index does not accurately assess small vessel disease, which is associated with diabetic foot ulcers.

Answer B: Capillary refill time, when delayed, may suggest decreased limb perfusion. This is a nonspecific test, as decreased limb perfusion can be caused by peripheral arterial disease, volume depletion, or hypotension.

Answer C: Contrast-enhanced foot MRI is the most sensitive and specific test to identify soft tissue complications of acute osteomyelitis. This patient has no clinical features of osteomyelitis (fever, chills, or malaise, ulcer that probes to bone) and does not require imaging currently.

Answer D: Knee reflex testing is not useful in assessing diabetic neuropathy. While diabetic neuropathy can affect large nerve fibers in the lower extremities, it typically impairs ankle reflexes while sparing knee reflexes.

Bullet Summary:
Preventative measures for diabetic foot ulcers should focus on regular foot exams with monofilament testing to assess for diabetic neuropathy.


Question: A 72-year-old man with a history of type 2 diabetes mellitus, hypertension, and hyperlipidemia presents to his primary care provider for concerns about his cognitive decline. His wife has noticed that he has a worsening ability to organize, plan, and exhibit impulse control over the last month. The patient states that he is able to complete his activities of daily living without assistance, but has some weakness of his left upper and lower extremities that began 3 months prior. He needs reminders from his wife about daily tasks to complete. He enjoys spending time with his spouse, playing cards with his friends, and taking daily walks around his neighborhood. His temperature is 98.2°F (36.8°C), blood pressure is 149/87 mmHg, pulse is 87/min, and respirations are 12/min. Physical exam reveals an elderly man who is oriented to person, place, and time. He has 4/5 left-sided weakness of the upper and lower extremities and associated pronator drift of the left upper extremity. A mini-mental status exam reveals he is able to remember 2 out of 3 words after 4 minutes. He is able to appropriately draw a clock. A magnetic resonance imaging study of the brain is shown in Figure A. Which of the following is the most likely diagnosis?

Answer: Vascular dementia

Explanation:
This patient with cardiovascular risk factors (hypertension, type 2 diabetes mellitus, hyperlipidemia) who presents with sudden cognitive decline of executive function and neurologic symptoms consistent with vasculopathy and possible prior stroke given his neurologic exam likely has vascular dementia, which can be corroborated with magnetic resonance imaging revealing white matter focal involvement consistent with vascular infarcts.

Vascular dementia is a form of dementia that results from compromise of blood supply to the brain, such as minor strokes or microinfarcts to the white matter. These insults lead to worsening cognitive abilities and presents classically as a stepwise decline (sudden/sharp declines in cognitive function that occur at distinct periods of time, not gradually) in cognitive function (thinking, planning, self-control, flexibility in thought). This is often associated with neurologic deficits as byproducts of these strokes. Unlike other forms of dementia, this presentation is step-wise. Treatment involves optimizing medical management to treat underlying medical comorbidities (managing cardiovascular risk factors such as hypertension, type 2 diabetes mellitus, hyperlipidemia), physical therapy/rehab for stroke symptoms, and caregiver support at home. Magnetic resonance imaging reveals focal white matter changes consistent with small vascular infarcts.

Khan et al. review the diagnosis and management of vascular dementia while including commentary on recent updates in the literature. They found that risk factors for vascular diseases such as stroke, high blood pressure, high cholesterol, and smoking also raise the risk of vascular dementia. They thus recommend medical management of underlying medical comorbidities such as hypertension, diabetes mellitus, or hyperlipidemia as treatments for vascular dementia.

Figure/Illustration A shows magnetic resonance imaging with white matter small vessel ischemic changes (red arrows) characteristic of vascular dementia within a background of diffuse generalized atrophy.

Incorrect Answers:
Answer A: Alzheimer disease is a form of dementia that presents with progressive forgetfulness as the first and most jarring clinical symptom, followed by worsening visual/spatial recognition, and then worsening behavioral function. It is most common in patients over the age of 75. It is not associated with focal deficits or weakness on neurological exam.

Answer B: Mild cognitive impairment is a stage between the expected cognitive decline of normal aging and forms of dementia. Patients and family members may notice problems with memory, thinking, or judgment, but they are not significant enough to cause interference with activities of daily living.

Answer C: Normal aging does not involve a noticeable decline in cognition and does not involve neurologic deficits. Declines are present, but are infrequent and do not impede activities of daily living.

Answer D: Pseudodementia is the result of untreated depression, which can present as forgetfulness in the elderly. This etiology can be distinguished by screening for signs or symptoms of depression, which might include sleep disturbance, anhedonia, lack of energy, increased or decreased appetite, fatigue, and/or loss of concentration. These symptoms are absent in this case.

Bullet Summary:
Vascular dementia presents with a step-wise decline in executive cognitive function and neurologic deficits in a patient with cardiovascular risk factors and is associate with MRI findings including white matter changes consistent with vascular infarcts.


Question: An 83-year-old man is brought to the emergency department by his daughter due to confusion over the last 2 weeks. The patient initially became less talkative than usual before starting to confuse her with her sister. The patient also could not remember what day of the week it was and he was out of groceries and likely had been for several days when visited. While she was talking to him, he fell asleep and was difficult to rouse. The patient is unable to provide a clear history. He has a medical history of hypertension, glaucoma, and osteoarthritis in his left knee that requires him to walk with a cane. He takes hydrochlorothiazide, timolol eyedrops, and occasional acetaminophen. His temperature is 98.5° F (36.9° C), blood pressure is 122/74 mmHg, pulse is 75/min, and respirations are 14/min. The patient is lethargic but arousable, oriented only to person, and disheveled. Neurologic exam reveals intact cranial nerves, 1+ deep tendon reflexes throughout, and 4/5 strength in all extremities. There is a 3 x 5 cm green-blue area of ecchymosis on the lateral aspect of his left knee. A CT of the head without contrast is performed and shown in Figure A. Which of the following factors plays the earliest role in the progression towards this patient’s presentation?

Answer: Cerebral atrophy

Explanation:
This patient is an elderly man with progressive confusion over weeks, a nonfocal neurologic exam, and a CT of the head showing a hypodense crescent, most consistent with chronic subdural hematoma (SDH). Cerebral atrophy plays the earliest role in this presentation, resulting in exposure of the bridging veins and subsequent rupture with even minor trauma.

Chronic subdural hematomas present gradually, most often with headaches, somnolence, light-headedness, cognitive impairment, and rarely, seizures. Typically, the neurologic exam is largely normal but rarely focal deficits such as contralateral hemiparesis from compression of the cortex underlying the hematoma or ipsilateral hemiparesis from the lateral displacement of the opposite cortex may occur. Chronic SDH most often occurs in the setting of cerebral atrophy related to increased age, chronic alcohol use, and prior traumatic brain injury. Exposure of the bridging veins allows even minor trauma to precipitate subdural bleeding. A non-contrast CT of the head is indicated in any elderly patient with decreased mentation and concern for chronic SDH. Since old blood appears hypodense, imaging will allow for the determination of whether the bleed is acute or chronic. Supportive care is usually sufficient for treatment but surgical evacuation of the hematoma can be considered in patients with focal deficits or an expanding hematoma.

Mehta et al. review the evidence regarding the diagnosis and management of chronic subdural hematomas in elderly patients. They discuss how crescentic layering of fluid in the subdural space on a non-contrast computed tomography scan is diagnostic of this condition. They recommend close follow-up as many patients will develop a recurrence of this condition.

Figure/Illustration A shows a non-contrast CT scan of the head with a hypodense crescent left side (red circle). This finding is consistent with a chronic subdural hematoma.

Incorrect Answers:
Answer A: Aneurysmal rupture is an extremely uncommon cause of SDH and typically causes subarachnoid hemorrhage instead. It often presents with “the worst headache of my life” or “thunderclap headache,” and would show hyperdensity in the subarachnoid space on head CT. Surgical clipping or endovascular treatment can prevent rebleeding.

Answer C: Elder abuse can be subtle and should always be considered when an elderly patient presents with confusion, bruising, or dishevelment. In children, abuse is an important cause of SDH, which may occur in the setting of “shaken baby syndrome.” However, abuse is not especially associated with chronic SDH in the elderly population, and there is another plausible reason for this patient’s presentation (trauma from a fall as evidenced by the resolving ecchymosis on his knee).

Answer D: Hypertension is a major risk factor for stroke, which typically presents with focal neurologic deficits such as hemiparesis, aphasia, or sensory loss. Although this patient does have a history of hypertension, he is normotensive in the emergency room and has non-focal neurologic decline that has been slowly progressive, which is less consistent with stroke. Furthermore, in contrast to this patient’s CT scan, acute ischemic stroke would likely present with a normal head CT and prior infarct would cause a hypodensity in the parenchyma itself. Treatment is with risk factor optimization when a patient presents outside the window for thrombolytic agents.

Answer E: Increased CSF due to poor reabsorption by arachnoid granules is the cause of normal pressure hydrocephalus (NPH). Patients typically present with the “wet, wacky, and wobbly” triad – urinary incontinence, mental status changes, and magnetic gait. Head CT would show dilated ventricles and management includes CSF shunting.

Bullet Summary:
Chronic subdural hematomas may occur in elderly patients due to cerebral atrophy and subsequent exposure of bridging veins that may tear with minor trauma.


Question: A 68-year-old woman presents to the emergency room with several days of frequent, nonbloody, watery stools. She recently completed a course of clindamycin 2 weeks ago for a tooth infection. Her medical history is notable for hypertension and hyperlipidemia for which she takes amlodipine and atorvastatin. She traveled recently and has no sick contacts. Her temperature is 37.0°C (98.6°F), blood pressure is 118/82 mmHg, pulse is 98/min, respirations are 14/min, and oxygen saturation is 98% on room air. On exam, her abdomen is soft, non-distended, and non-tender to palpation; however she has diffuse discomfort upon palpation of the abdomen with no rebound, rigidity, or guarding. Which of the following is most likely to confirm the diagnosis?

Answer: Stool toxin assay

Explanation:
This patient presenting with cramping abdominal pain and frequent watery diarrhea a few weeks after finishing a course of antibiotics most likely has Clostridioides difficile infection, for which the most appropriate confirmatory test is a stool toxin assay.

C. difficile infection should be suspected in patients with acute and clinically significant diarrhea with no obvious alternative explanation. It is associated with risk factors such as recent antibiotic use, hospitalization, and advanced age. Diagnosis is established via a positive enzyme immunoassay for C. difficile toxins and C. difficile glutamate dehydrogenase (GDH), or a positive nucleic acid amplification test (NAAT) for C. difficile toxins. The GDH enzyme immunoassay is highly sensitive for detecting C. difficile, but not specific for toxin-producing C. difficile, and thus the toxin enzyme immunoassay is submitted in conjunction. If the results of both are discordant, then NAAT is used to make the diagnosis. Treatment for C. difficile infection differs by disease severity and recurrence. Commonly used medications include fidaxomicin and oral vancomycin.

McDonald et al. review the guidelines for diagnosis and treatment of C. difficile and provide the algorithm for C. difficile testing as mentioned above. The authors also note that only liquid stool from patients with clinically significant and acute diarrhea should be submitted for testing. The authors recommend that formed stool from asymptomatic patients should not be tested because the presence of the C. difficile toxin gene does not distinguish between infection and asymptomatic carriage.

Incorrect Answers:
Answer A: Abdominal radiograph is an appropriate adjunctive diagnostic tool in patients with severe disease (e.g., severe abdominal pain and distension, fever, hypovolemia, lactic acidosis, marked leukocytosis) or fulminant colitis (marked by hypotension and ileus) to evaluate for toxic megacolon, bowel perforation, or other findings that warrant surgical intervention. In patients who are stable with low concern for severe disease or fulminant colitis, it would not be the preferred initial test for diagnosis nor would it be confirmatory.

Answer B: CT imaging of the abdomen and pelvis with oral and intravenous contrast is the preferred modality for detecting the presence of toxic megacolon, bowel perforation, or other findings that warrant surgical intervention in the setting of C. difficile colitis. Colonic dilatation of > 7 cm in diameter in the clinical setting of severe C. difficile infection is diagnostic. Other findings may include small bowel dilatation or scalloping of the bowel wall due to submucosal edema. While it would be reasonable to perform a CT scan in this patient, it would not confirm the diagnosis.

Answer C: Flexible sigmoidoscopy would be appropriate for cases in which an alternative diagnosis is suspected that requires direct visualization and/or biopsy of the bowel mucosa. It may also be helpful for patients with ileus or colitis in the absence of diarrhea as it allows for visualization of pseudomembranes on the inflamed mucosal surface, which are highly suggestive of C. difficile infection. In general, colonoscopy is a preferred and more accurate test.

Answer D: Rectal swab for selective anaerobic culture involves culture on a selective medium with toxin testing of isolated C. difficile. It is a highly sensitive test, but culture cannot distinguish toxin-producing strains from non-toxin-producing strains. A second test is required to detect toxin production by the cultured C. difficile strain (either enzyme immunoassay or nucleic acid amplification testing). Culture takes several days to finalize and as such, it is seldom used to establish a clinical diagnosis. It is most useful in patients with ileus and suspected C. difficile infection.

Bullet Summary:
The most appropriate confirmatory test for diagnosis of Clostridioides difficile infection is a stool toxin assay.


Question:
A 27-year-old nurse presents to the emergency department with a 30-minute history of palpitations and chest pain. She has been experiencing nausea, vomiting, and diarrhea after eating leftovers 2 days ago. Her husband tells the physician that he is concerned that the patient has been increasingly obsessed about her weight recently. She has a history of major depressive disorder for which she takes escitalopram. Her temperature is 98.6°F (37.0°C), blood pressure is 110/72 mmHg, pulse is 110/min, and respirations are 11/min. Physical examination is notable for dry mucous membranes and tachycardia with regular rhythm. Laboratory testing shows the following results:

Serum:
Na+: 135 mEq/L
Cl-: 96 mEq/L
K+: 2.9 mEq/L
HCO3-: 36 mEq/L

Venous blood gas shows a pH of 7.52. Which of the following tests is most appropriate in differentiating between different etiologies of this patient's lab abnormalities?

Answer: Urine chloride

Explanation:
This patient who presents with hypokalemia and metabolic alkalosis may either be vomiting or engaging in diuretic abuse. A urine chloride test can be used to distinguish between these possibilities because urine chloride will be high in diuretic abuse and will be low/normal in surreptitious vomiting.

Metabolic alkalosis is an acid-base disorder that is due to an increased level of serum bicarbonate. This increase can be secondary to increased bicarbonate intake or loss of hydrogen ions. Etiologies consistent with increased intake include antacid use or milk-alkali syndrome. Etiologies consistent with hydrogen ion loss include gastrointestinal losses such as vomiting or renal losses such as hyperaldosteronism, Bartter syndrome, or diuretic abuse. Urine chloride can distinguish between gastrointestinal and renal losses because urine chloride levels will be high in patients with renal tubule dysfunction or diuretic abuse. This is due to increased urinary excretion of ammonium chloride in cases of diarrhea. On the other hand, urine chloride will generally be low in hyperaldosteronism due to loss of chloride with vomiting.

Wu et al. studied the causes of chronic hypokalemia as well as laboratory findings that can be used to distinguish between different etiologies. They show how urine sodium and chloride can be helpful for identifying the surreptitious use of diuretics. The authors recommend the use of the sodium-to-chloride excretion ratio to help diagnose patients with chronic normotensive hypokalemia.

Incorrect Answers:
Answer A: Arterial blood gas is useful for determining the acid-base state of a patient because it simultaneously measures carbon dioxide and bicarbonate levels. This test is not as useful in determining different causes of metabolic alkalosis because all of these etiologies will have similar findings (high bicarbonate and compensatory high carbon dioxide), especially in patient who has already received a venous blood gas.

Answer B: Complete blood count is useful for determining whether a patient is anemic resulting in decreased oxygen delivery to end organs due to decreased carrying capacity for oxygen. In cases of severe anemia and hypoperfusion, peripheral tissues produce lactic acid which will result in an anion gap metabolic acidosis rather than metabolic alkalosis.

Answer C: Serum glucose elevation can result in increased diuresis as well as pseudohyponatremia (decreased measured sodium due to increased glucose). Alternatively, acidosis may also be caused by insulin deficiency in diabetic ketoacidosis. Neither of these findings is consistent with the lab results seen in this patient.

Answer E: Urine toxicology can be used to determine whether the patient is taking any substances of abuse. There is no pathognomonic acid-base finding that can aid in diagnosing overdose and/or substance abuse. However, most standard urine toxicology screens do not detect the use of diuretics.

Bullet Summary:
Urine chloride can distinguish between gastrointestinal and renal causes of metabolic alkalosis.


Question: A 65-year-old man presents to the emergency department with anxiety and intermittent palpitations. He began feeling the palpitations 3 days ago while eating dinner. He denies chest pain, shortness of breath, or loss of consciousness. He has a history of hypertension, major depressive disorder, Raynaud disease, and chronic obstructive pulmonary disease (COPD) on 2 liters of oxygen at home. Current medications include lisinopril, inhaled umeclidinium-vilanterol, and as-needed albuterol. He drinks 4 beers a day and has smoked 1 pack of cigarettes a day for 40 years. His temperature is 98.9° F (37.2° C), blood pressure is 130/85 mmHg, pulse is 125/min, and respirations are 16/min. Physical exam is notable for an irregular pulse and scattered end-expiratory wheezes. An echocardiogram performed 1 month ago showed a left ventricular ejection fraction of 60-65%. The patient requires 3 liters of oxygen today. An ECG is performed as seen in Figure A. Which of the following is the most appropriate treatment for the patient’s tachycardia?

Answer: Verapamil

Explanation:
This patient’s new-onset palpitations, irregularly irregular pulse, and absent p-waves on ECG are consistent with atrial fibrillation. In hemodynamically stable patients with a relative contraindication to β-blockers (COPD on home oxygen with increasing oxygen need), rate control with a non-dihydropyridine calcium channel blocker such as verapamil is preferred.

Atrial fibrillation can present with palpitations, lightheadedness, or shortness of breath. ECG findings will be an irregularly irregular rhythm and absent P waves with an erratic baseline as shown in Illustration A. Treatment is centered on rate control. First-line agents for rate control include β1 selective blockers (metoprolol and esmolol) and non-dihydropyridine calcium channel blockers (verapamil and diltiazem). In patients with COPD, non-selective β-blockers (propranolol, timolol, and sotalol) can worsen bronchoconstriction by activating β2-adrenoreceptors. Other relative contraindications to β-blockers include Raynaud disease and depression (increased risk of fatigue and sexual dysfunction). In patients with relative contraindications to β-blockers, non-dihydropyridine calcium channel blockers are the preferred initial treatment option.

Van Gelder et al. studied lenient (resting heart rate < 110 beats per minute) versus strict rate control (resting heart rate < 80 beats per minute) in patients with atrial fibrillation in a randomized control trial. The authors found that there was no difference in the primary composite outcome of death from cardiovascular causes, hospitalization for heart failure, stroke, bleeding, and life-threatening arrhythmias between the 2 groups. The authors recommend a lenient rate control strategy in patients with atrial fibrillation.

Figure/Illustration A is an ECG lacking P waves (red arrows) and irregularly irregular RR intervals (red/blue lines), which are classic findings in atrial fibrillation.

Incorrect Answers:
Answer A: Amiodarone is an antiarrhythmic that can be used in patients to convert atrial fibrillation to sinus rhythm. It is often suitable to use in patients with depressed left ventricular function. Amiodarone has multiple multi-system adverse effects including pulmonary toxicity, and it is not used as a first-line agent.

Answer B: Clopidogrel is an antiplatelet agent that can be used to reduce the risk of thrombosis. Although patients with atrial fibrillation are at increased risk of stroke, the preferred anticoagulation agents are warfarin or direct oral anticoagulants (apixaban).

Answer C: Digoxin can be used as a rate control agent in atrial fibrillation as it directly suppresses atrioventricular nodal conduction. Due to its narrow therapeutic window and risk of toxicity, it is used as second-line therapy when first-line agents fail.

Answer D: Metoprolol is a β-blocker that is a first-line agent for rate control in atrial fibrillation. In patients with contraindications to β-blockers, non-dihydropyridine calcium channel blockers are the treatment of choice. This patient has COPD with increasing oxygen needs making calcium channel blockers possibly a better choice.

Bullet Summary:
In hemodynamically stable patients with atrial fibrillation and relative contraindications to β-blockers, non-dihydropyridine calcium channel blockers are the treatment of choice.


Question: A 24-year-old motorcyclist is involved in a head-on collision with a motor vehicle and suffers various traumatic injuries. She has no significant medical history, is up to date on all vaccinations, and her last tetanus shot was 3 years ago. On arrival, her temperature is 36.7°C (98°F), blood pressure is 82/63 mmHg, pulse is 120/min, respirations are 20/min, and oxygen saturation is 97% on 2L oxygen nasal cannula. On physical exam, there are extensive ecchymoses and abrasions along her left posterior ribs and left flank. A CT scan of the abdomen is obtained, which is shown in Figure A. After the appropriate surgical intervention is performed for the grade V splenic injury, which of the following is the most appropriate next step in management?

Vaccination against Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae

Answer: Vaccination against Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae

Explanation:
This patient has an extensive splenic injury and hemodynamic instability requiring splenectomy, as evidenced by trauma to the left posterior ribs and left flank, low blood pressures with reflex tachycardia, and evidence of splenic rupture and hemoperitoneum on computed tomography imaging. Subsequently, this asplenic patient will require vaccination against encapsulated bacteria such as S. pneumoniae, N. meningitidis, and H. influenzae.

The capsules of encapsulated bacteria serve as an antiphagocytic virulence factor. To clear these bacteria, opsonization and subsequent clearance by the spleen must occur. In the setting of asplenia, opsonization capability is significantly decreased and thus asplenic patients are at high risk of severe infections by encapsulated bacteria. As such, asplenic patients require vaccination against the encapsulated bacteria S. pneumoniae, N. meningitidis, and H. influenza.

Patton et al. review recommendations for serogroup B meningococcal vaccination. The authors find that for patients aged 10 to 25 years old who are at increased risk for meningococcal disease (asplenic patients); 3 doses of the MenB-FHbp vaccine should be given. The authors recommend the administration of only 2 doses of the vaccine to patients that are not at elevated risk.

Figure/Illustration A depicts a traumatic splenic rupture with perisplenic hemoperitoneum (red circle).

Incorrect Answers:
Answer A: Insertion of a nasogastric tube would be appropriate in a patient with bowel obstruction or significant post-operative ileus. There is no evidence that this patient is experiencing obstruction or ileus, which typically presents with nausea, vomiting, abdominal pain, bloating, and lack of flatus or bowel movements.

Answer B: Insertion of a thoracostomy tube is not indicated in this patient as there is no evidence of pneumothorax or hemothorax. Patients with pneumothorax or hemothorax typically present with tachycardia, tachypnea, and decreased oxygen saturation. On exam, such patients may have decreased breath sounds. Ultrasonography may also reveal the absence of lung sliding.

Answer C: Prophylactic intravenous antibiotics are not indicated in the immediate post-operative period for asplenic adults. However, daily oral antibiotic prophylaxis is indicated in asplenic patients with a history of another concurrent immunocompromising condition or a history of severe infection due to an encapsulated organism.

Answer D: Tetanus vaccination is indicated every 10 years in patients who have previously received 3 doses of the tetanus vaccine and have clean or minor wounds. In patients with more extensive wounds who have previously received 3 doses of tetanus vaccine, re-vaccination is only necessary if their last tetanus vaccine was 5 or more years ago. This patient has extensive abrasions but is up to date on all vaccines and last received a tetanus vaccine 3 years ago, so a re-vaccination during this time is not indicated.

Bullet Summary:
Asplenic patients are at increased risk of severe infection by encapsulated bacteria; thus patients that undergo splenic removal require vaccination against Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae within 14 days of the procedure.


Question: A 46-year-old farmer presents to the office for a follow-up visit. He was seen 4 days ago for a new lesion on his arm that had been present for 1 week prior to that visit. A photograph of the lesion is shown in Figure A. At that time, he was prescribed treatment for the lesion and instructed to follow up as necessary. Today, he reports that he became sunburned this morning within an hour of beginning his workday, despite wearing appropriate sunscreen. He has a medical history significant for type 2 diabetes mellitus that is controlled with metformin. He has no known medical allergies. He smokes 1 pack of cigarettes per day and denies alcohol or illicit drug use. His temperature is 98.6°F (37.0°C), blood pressure is 125/70 mmHg, pulse is 65/min, and respirations are 12/min. On exam, there is a blistering erythematous rash on the arms and shoulders. The previous skin lesion appears unchanged. Which of the following is the most likely explanation for the patient's new rash?

Progression of disease and surgical debridement is necessary

Answer: Adverse effect of doxycycline

Explanation:
This farmer has a cutaneous black eschar most consistent with cutaneous anthrax for which doxycycline is an appropriate treatment. A new blistering, erythematous rash after spending an hour outside that appears 4 days after starting treatment is consistent with a photosensitivity reaction, a known adverse effect of doxycycline.

Cutaneous anthrax is the most common form of infection caused by Bacillus anthracis. The infection is contracted during contact with infected livestock. The first-line treatment is doxycycline, ciprofloxacin, levofloxacin, or moxifloxacin. Progression to systemic anthrax would result in pulmonary (flu-like symptoms and hemoptysis) or gastrointestinal (nausea, vomiting, and dysentery) symptoms and would require treatment with clindamycin plus ciprofloxacin. Patients with meningitis due to anthrax require antibiotic therapy with ciprofloxacin plus meropenem plus linezolid. Additionally, antitoxins such as raxibacumab and adjunctive therapies such as glucocorticoids should be considered. In addition to photosensitivity, adverse effects of doxycycline include gastrointestinal upset (most common), teeth discoloration, and inhibition of bone growth in children. Doxycycline is teratogenic and should not be prescribed during pregnancy.

Migone et al. discuss the use of raxibacumab, a monoclonal antibody against a component of the anthrax toxin, in treating inhalational anthrax. The authors found that in monkeys, raxibacumab significantly increased survival after exposure to anthrax. The authors recommend the use of antitoxins such as raxibacumab in any patient suspected of having systemic anthrax.

Figure/Illustration A demonstrates the characteristic black eschar (blue circle) of cutaneous anthrax.

Incorrect Answers:
Answer A: Adverse effects of ciprofloxacin do not include photosensitivity, though it is an appropriate antibiotic choice for cutaneous anthrax treatment. Adverse effects of ciprofloxacin include gastrointestinal upset, risk of tendon rupture, and QT prolongation.

Answer C: Allergic reactions to prescribed therapy would be characterized by urticaria and wheals. In severe cases, anaphylaxis may be present.

Answer D: Progression of disease and alternative therapy is indicated does not fit this case. The patient's symptoms (blistering, erythematous rash) are not concerning for the progression of cutaneous anthrax to systemic disease, which would result in pulmonary or gastrointestinal symptoms. Alternative therapy for systemic anthrax is not indicated in this case.

Answer E: Progression of disease and surgical debridement is not indicated. The patient's symptoms (blistering, erythematous rash) are not concerning for the progression of cutaneous anthrax to systemic disease, which would result in pulmonary or gastrointestinal symptoms. Additionally, surgical debridement is not indicated for cutaneous anthrax.

Bullet Summary:
Cutaneous anthrax presents with a black eschar and is treated with antitoxin and either doxycycline or ciprofloxacin, the former of which can cause a photosensitivity reaction.


Question:
A 47-year-old woman presents to the clinic with 3 weeks of increased thirst and urination. She has a history of obesity, hypertension, and depression for which she takes losartan and sertraline. She has smoked 1 pack of cigarettes per day for 30 years. Her temperature is 99.5°F (37.5°C), blood pressure is 148/90 mmHg, pulse is 84/min, and respirations are 15/min. Physical exam is unremarkable, including no costovertebral or suprapubic tenderness to palpation. Laboratory studies are performed and show:

Serum:
Na+: 140 mEq/L
K+: 4.4 mEq/L
HCO3-: 21 mEq/L
Blood urea nitrogen (BUN): 38 mg/dL
Creatinine: 1.1 mg/dL
Glucose: 215 mg/dL

Which of the following is the most appropriate screening test for nephropathy in this patient?

Answer: Urine albumin-to-creatinine ratio

Explanation:
This patient with a history of obesity and hypertension presenting with polyuria and polydipsia in the setting of an elevated random blood glucose (> 200 mg/dL) likely has a new diagnosis of type 2 diabetes mellitus. The urine albumin-to-creatinine ratio is the most appropriate early test for diabetic nephropathy.

Early detection of diabetic nephropathy is key to management, as the complication eventually leads to overt kidney disease and renal failure. The diagnosis of diabetic nephropathy is based on > 30 mg/g of albuminuria for > 3 months. Patients with type 2 diabetes mellitus should be screened annually with a random urine albumin-to-creatinine ratio starting at diagnosis. Elevation of urine albumin warrants treatment with ACE inhibitors or angiotensin receptor blockers. Blood pressure control slows the progression of diabetic nephropathy. Patients with type 2 diabetes mellitus and diabetic nephropathy should be started on a sodium-glucose cotransporter 2 (SGLT2) inhibitor. Patients with persistent albuminuria despite both ACE/ARB and SGLT2 inhibitor therapy should be started on the nonsteroidal selective mineralocorticoid receptor antagonist (MRA) finerenone.

Bakris et al. study the efficacy of finerenone, a nonsteroidal selective MRA, in the treatment of patients with albuminuria in patients with chronic kidney disease (CKD) and type 2 diabetes. The authors found in a randomized control trial that finerenone reduced the incidence of a composite outcome of kidney failure. The authors recommend the use of finerenone in patients with persistent albuminuria despite optimal medical therapy to prevent risks of CKD progression and cardiovascular events.

Incorrect Answers:
Answer A: Creatinine clearance changes over the time course of diabetic nephropathy and can be normal or elevated (due to glomerular hyperfiltration) in early diabetic nephropathy. Therefore, it is an unreliable test for early diabetic nephropathy compared to the more sensitive urine albumin-to-creatinine ratio.

Answer B: Hemoglobin A1c is a test that reflects the average blood glucose over the past 2 to 3 months. While this test provides information on a patient's glycemic control, it does not directly assess the presence or extent of diabetic nephropathy.

Answer C: Oral glucose tolerance test is the test of choice for diagnosing gestational diabetes. It does not play a role in the detection of diabetic nephropathy.

Answer E: Urine protein dipstick is a useful test to detect proteinuria. This test is insensitive to low levels of albumin. Therefore, it is considered an inferior test to urine albumin-to-creatinine ratio in the diagnosis of diabetic nephropathy.

Bullet Summary:
Urine albumin-to-creatinine ratio testing is the most sensitive test to detect moderately elevated levels of urinary albumin excretion, a known byproduct of diabetic nephropathy.


Question: A 15-year-old boy is brought to his pediatrician for a follow-up visit. His parents report that he is doing well in school and has many friends. Their only concern is that he has a “difficult stomach.” Every few months, he complains of intermittent abdominal pain that takes several days to pass. He occasionally misses school due to the pain. There is blood in his stool during these episodes. These symptoms have persisted for many years. The parents have so far managed the condition using herbal teas and essential oils but have not sought formal medical care. His temperature is 98.2°F (36.8°C), blood pressure is 106/61 mmHg, pulse is 88/min, and respirations are 12/min. He has lost 10 pounds since his annual visit the year before and is the same height. On physical exam, the patient is thin with conjunctival pallor. His sclerae are anicteric and his abdomen is soft and non-tender without hepatosplenomegaly. He also has the findings seen in Figure A. He undergoes an abdominal CT that shows disease affecting the terminal ileum. Which of the following is most likely to be present in this patient?

Increased serum methylmalonic acid level

Answer: Increased serum methylmalonic acid level

Explanation:
This patient with episodic abdominal pain, bloody stool, growth failure, and erythema nodosum most likely has Crohn disease. Disease involving the terminal ileum predisposes patients to vitamin B12 deficiency, which would cause anemia with an elevated serum methylmalonic acid level.

Crohn disease is an inflammatory bowel disease that presents with abdominal pain, bloody stools, and growth failure in children. Extra-intestinal manifestations of Crohn disease include fistula formation and erythema nodosum, which appear as multiple tender erythematous nodules that fade after 1-2 weeks into bluish plaques or macules that can be confused with bruises. Complications of Crohn disease when the disease involves the terminal ileum is vitamin deficiency and malabsorption. These deficiencies can include vitamin A, vitamin D, vitamin E, vitamin K, zinc, and vitamin B12. Vitamin B12 deficiency presents with a macrocytic, megaloblastic anemia with hypersegmented neutrophils on peripheral blood smear. Lab findings include elevated serum homocysteine and methylmalonic acid levels. Vitamin B12 deficiency is also associated with peripheral neuropathy and should be treated with intramuscular vitamin repletion.

Akbulut presents the current state of evidence regarding vitamin deficiency in patients with Crohn disease. They found that vitamin B12 and folate levels are often low in patients with this disease. They recommend monitoring vitamin levels and providing repletion when necessary.

Figure/Illustration A is a clinical photograph showing erythematous nodules on the extensor surfaces of the legs (red circles). This finding is consistent with the latter stage of erythema nodosum.

Incorrect Answers:
Answer A: Decreased mean corpuscular volume may be seen in iron deficiency anemia, which can be co-morbid with Crohn disease. While this patient does have recurrent gastrointestinal blood loss, the very low frequency of his symptoms is unlikely to result in iron deficiency, making a decreased MCV less likely compared to an increased MCV given the underlying terminal ileum pathology.

Answer B: Decreased serum homocysteine level is not seen in any common human disease. An elevated (not decreased) serum homocysteine level is seen in vitamin B12 deficiency in addition to folate deficiency. This increase is due to the impaired processing of homocysteine in the absence of these cofactors.

Answer D: Microcytes would not be seen in vitamin B12 deficiency or folate deficiency, which instead present with macro-ovalocytes. Microcytic anemia would be seen in patients with iron deficiency anemia, which can present with fatigue and pallor in patients with occult bleeding. Iron supplementation and treatment of the underlying source of bleeding is appropriate care.

Answer E: A prolonged PTT could be seen in this patient as vitamin K absorption is likely affected. This patient is not presenting with a chief complaint of bruising/bleeding (the physical exam finding is erythema nodosum rather than ecchymosis), and symptoms point toward a diagnosis of anemia which would be associated with poor B12 absorption.

Bullet Summary:
Crohn disease may affect the terminal ileum, resulting in vitamin B12 deficiency (increasing the serum methylmalonic acid level) that would present with macrocytic, megaloblastic anemia with hypersegmented neutrophils on a peripheral blood smear.


Question: A 31-year-old woman presents to her obstetrician for her first prenatal visit after having a positive home pregnancy test 1 week ago. Her last menstrual period was 8 weeks ago. The patient has a medical history of type 1 diabetes mellitus since childhood and her home medications include insulin. Her hemoglobin A1c 2 weeks ago was 13.7%. At that time, she was also found to have microalbuminuria on routine urinalysis. Her primary care provider prescribed lisinopril but the patient has not yet started taking it. The patient’s brother is autistic but her family history is otherwise unremarkable. Her temperature is 98.6°F (37.0°C), blood pressure is 124/81 mmHg, pulse is 75/min, and respirations are 14/min. A physical exam is unremarkable. This fetus is most likely at increased risk for which of the following complications?

Answer: Neural tube defect

Explanation:
This patient has type 1 diabetes mellitus and presents in early pregnancy with a markedly elevated hemoglobin A1c, suggesting poor glycemic control. Poor glycemic control increases the risk of a neural tube defect in the fetus.

Infants of diabetic mothers (IDM) are at increased risk of many congenital malformations as well as postnatal complications. These risks are more likely if there is poor maternal glycemic control, especially in the periconceptional period. Poorly controlled hemoglobin A1c and microalbuminuria on urinalysis indicate long-standing poor glycemic control and indicate a poor prognosis. The most common anomalies in IDM are cardiovascular defects such as septal defects and transposition of the great arteries as well as neural tube defects such as anencephaly and spina bifida. Sacral agenesis, or a poorly developed caudal spine and spinal cord, as well as small left colon syndrome due to a meconium plug, are other common malformations seen in IDM. General complications in IDM include prematurity, intrauterine growth restriction or macrosomia, and miscarriage. Risk is minimized by tight glycemic control throughout pregnancy.

Dean et al. summarize the evidence surrounding micronutrients and obesity in pregnancy. They found that patients with diabetes had a higher risk of having infants with a neural tube or a congenital heart defect. They recommend using folic acid supplementation in all patients to reduce the risk of neural tube defects.

Incorrect Answers:
Answer A: Aneuoploidy risk is not increased in IDM. This complication is associated with advanced maternal age. This patient is at baseline risk since she is below the “advanced maternal age” cutoff of 35 years. Some of the values used in aneuploidy screening (maternal serum alphafetoprotein, estriol, and inhibin A) are generally lower in women with diabetes. Guidelines specific to this patient population should be used for the aneuploidy screen so as to avoid false positive results.

Answer B: Neonatal hyperglycemia is not seen in IDM. Patients may experience hypoglycemia. This is due to the crossing of glucose from the mother to the fetus via the placenta and subsequent hyperinsulinemia and ß-cell hyperplasia from the fetus. After delivery, the high insulin levels cause hypoglycemia because there is no longer an overabundant source of glucose. Hyperglycemia in infants is much less common and can be due to glucose infusion or sepsis.

Answer D: Oligohydramnios is not specifically associated with maternal hyperglycemia. Instead, patients may experience polyhydramnios. The mechanism for increased amniotic fluid is unclear, though some speculate that fetal hyperglycemia results in polyuria and thus polyhydramnios. Severe oligohydramnios can cause pulmonary hypoplasia and clubfoot as well as cord compression, while polyhydramnios is associated with cord prolapse, placental abruption, and prematurity.

Answer E: Post-term delivery occurs after 42 weeks gestation. Maternal diabetes typically causes prematurity. Post-term delivery is associated with fetal malnutrition, hypoxemia, and oligohydramnios due to suboptimal functioning of the placenta. The risk of meconium aspiration increases as gestational age increases. Induction of labor is generally performed at 42 weeks to avoid these complications.

Bullet Summary:
Maternal hyperglycemia from diabetes mellitus is associated with congenital heart defects, neural tube defects, and small left colon syndrome.


Question: A 34-year-old man is brought to a rural emergency department by ambulance after being involved in a motor vehicle accident. Paramedics report that the patient was driving the car and crashed into a tree at roughly 25 miles per hour. There were no passengers and he was awake but disoriented at the scene. His temperature is 97.9°F (36.6°C), blood pressure is 131/88 mmHg, pulse is 89/min, and respirations are 14/min. He is speaking but is confused, opens his eyes to voice commands, and follows simple commands. He has multiple lacerations on his face and arms and smells of alcohol and marijuana. His cardiac exam is normal and his lungs are clear to auscultation bilaterally. He has bruising over his abdomen without any tenderness to palpation, distension, or rigidity. Which of the following is the most appropriate next step in management?

Focused abdominal sonography for trauma exam

Chest radiograph anterior-posterior and lateral

Answer: Abdominal and chest CT

Explanation:
This patient presents following a motor vehicle accident with a tender abdomen and stable vital signs. Given his stability, the most appropriate next step is an abdominal and chest CT.

In blunt abdominal trauma, the next step in management depends upon whether the patient is hemodynamically stable. With a normal blood pressure and pulse within the normal range, patients can undergo imaging to evaluate for injury to the abdominal organs with the most appropriate study being an abdominal CT with contrast. This study can accurately localize bleeding and aid in operative planning. A bedside ultrasound known as the FAST exam is often performed in unstable patients. Unstable patients, patients with abdominal tenderness, and patients with a severe mechanism of trauma may have a bedside FAST exam performed. If the free fluid is localized, the patient can be transferred directly to the operating room. Note that in many hospitals, the FAST exam is done simultaneously with the primary and secondary survey; however, if asked to choose which exam to perform on a trauma patient who is stable with no signs of a surgical abdomen, a CT scan should be performed to more accurately assess the patient's injuries and assess for injuries that may be missed by a FAST exam.

Feliciano reviewed the evidence surrounding the current diagnosis and management of abdominal trauma. He discusses how contrast-enhanced CT of the abdomen and pelvis is an important method for evaluating the etiology of intra-abdominal bleeding. He recommends considering damage control methods in the polytrauma patient.

Incorrect Answers:
Answer B: Chest radiography has limited utility in the setting of blunt abdominal trauma; however, a portable anterior-posterior film is often taken in trauma, in particular, when the patient is intoxicated. However, an anterior-posterior and lateral film would involve transporting the patient to radiology and positioning the patient. Thus it would be both difficult to obtain and less useful when compared to a CT scan given his traumatic injuries. Findings on chest radiograph could suggest abdominal injury, such as lower rib fractures or free air under the diaphragm, which would suggest intestinal perforation.

Answer C: Diagnostic laparoscopy may play a role in evaluating for injury in penetrating traumas such as gunshot wounds or stabbing wounds but would not be indicated as the most appropriate initial step in management in a stable patient. Unstable patients, surgical abdomens, and positive FAST exams or CT scans warrant transfer to the operating room.

Answer D: Diagnostic peritoneal lavage is a historical test to assess for intra-abdominal injury that was typically used with ambiguous FAST exams or patients where it was unclear whether there was abdominal bleeding; however, it has almost entirely been supplanted by the FAST exam.

Answer E: FAST exams are often performed with the primary or secondary survey in large institutions where resources are available. However, in small hospitals with limited resources, the most appropriate next step in management when deciding between a FAST exam or a CT scan should be made based on the mechanism and concern for bleeding. This stable patient with a benign exam can undergo a CT scan, which will offer more data than a FAST exam and would be performed regardless of whether a FAST exam was positive or negative given this patient's intoxication and abdominal bruising.

Bullet Summary:
In a patient who has experienced blunt abdominal trauma the most appropriate initial step in a stable patient is an abdominal CT scan.


Question:
A 2-month-old girl is brought to the pediatrician by her mother for a follow-up visit. The patient was born at 29 weeks gestation to a G1P1 mother. Her postnatal course was complicated by a prolonged neonatal intensive care unit stay for neonatal respiratory distress syndrome (NRDS). Since discharge from the hospital, her mother reports that the patient has been doing well without health problems. She has been gaining weight appropriately. Her temperature is 98.6°F (37.0°C), blood pressure is 80/50 mmHg, pulse is 120/min, and respirations are 25/min. The patient's mother asks the pediatrician about potentially delaying the 2-month vaccine doses due to the baby's medical history. Which of the following is the correct vaccination plan for this infant in terms of the vaccinations below?
- Diphtheria, Tetanus, and acellular Pertussis - DTaP
- Hepatitis A - HAV
- Hepatitis B - HBV
- Haemophilus influenzae type B conjugate - HiB
- Pneumococcal conjugate - PCV 13

Delay all vaccines for 2 months due to the infant's history of NRDS

Administer DTaP, HAV, HBV, HiB, PCV 13, poliovirus, and rotavirus vaccines

Administer DTaP, HBV, HiB, PCV 13, poliovirus, and rotavirus vaccines

Delay all vaccines for 2 months because the infant was born 2 months premature

Answer: Administer DTaP, HBV, HiB, PCV 13, poliovirus, and rotavirus vaccines

Explanation:
This 2-month-old girl has a history of prematurity (born at 29 weeks gestation) complicated by a NICU stay for NRDS but is healthy at this time. It is recommended that she receive all vaccines (DTaP, HBV, HiB, PCV 13, poliovirus, and rotavirus vaccines) as scheduled during this visit.

Premature infants can safely be vaccinated on the regular schedule against serious infections. A history of both prematurity and respiratory disease makes a patient more at risk for these serious infections, increasing the importance of vaccinations. The regular vaccine schedule recommends the following vaccines at 2 months of age: DTaP (inactivated), HBV (subunit), HiB (inactivated), PCV 13 (inactivated), poliovirus (inactivated), and rotavirus (live-attenuated). The first dose of the HBV (subunit) vaccine is still given during the first 24 hours of life unless the child is born with a birth weight of < 2000 grams (4 pounds 6 ounces).

Saari et al. discuss the recommendations of the American Academy of Pediatrics Committee on Infectious Diseases for the immunization of preterm infants. The authors find that preterm infants are less likely to receive recommended vaccines on time. The authors recommend also administering the influenza vaccine beginning at 6 months of age during the influenza season.

Incorrect Answers:
Answer A: Administering DTaP, HAV, HBV, HiB, PCV 13, poliovirus, and rotavirus vaccines is incorrect as this answer choice includes the vaccine for the hepatitis A virus. The first dose of this vaccine is given at 12-24 months of age.

Answer B: Administering DTaP, HBV, HiB, PCV 13, and poliovirus vaccines is incorrect as this answer choice is missing the rotavirus vaccine. Despite being premature and having a history of NRDS, live vaccines are safe to administer on schedule to this infant.

Answer D: Delaying all vaccines for 2 months due to the infant's history of NRDS is incorrect as while this child has a history of NRDS, she is currently healthy. It is safe to administer all vaccines on the regular schedule to this patient.

Answer E: Delaying all vaccines for 2 months because the infant was born 2 months premature is incorrect as it is not recommended that previously premature infants, with or without a perinatal complication such as NRDS, delay vaccines to account for the discrepancy between gestational and chronologic age.

Bullet Summary:
Children born with a history of prematurity, with or without health complications in their early life secondary to their prematurity, should receive all recommended vaccines as scheduled.


Question:
A 26-year-old woman presents to the clinic with diarrhea, bloating, flatulence, and abdominal cramps. These symptoms have been going on for 2 months. She has lost 6 pounds (2.7 kg) over these 2 months. Her medical history is significant for mild intermittent asthma for which she uses an albuterol inhaler as needed. She is sexually active with 1 male partner. She recently returned from South India following a mission trip for 6 weeks. Her temperature is 98.6°F (37.0°C), blood pressure is 105/70 mmHg, pulse is 95/min, and respirations are 14/min. On examination, the patient’s skin is pale. Labs are obtained and show the following results:

Leukocyte count: 4,500/mm^3
Hemoglobin: 10.5 g/dL
Platelets: 110,000/mm^3
Mean corpuscular volume (MCV): 116 µm^3
Reticulocyte count: 0.5%

A biopsy of the small bowel reveals blunting of villi and a mixed infiltration of lymphocytes, plasma cells, and eosinophils. Which of the following is the most likely diagnosis?

Answer: Tropical sprue

Explanation:
The patient is presenting with chronic diarrhea, weight loss, megaloblastic anemia (low hemoglobin and elevated MCV), and a biopsy showing blunted villi and mixed infiltrate following significant travel to South India. This is consistent with tropical sprue.

Tropical sprue is characterized by chronic diarrhea that occurs after travel to an endemic area. It is thought to be due to a bacterial overgrowth/infection that then damages the intestinal mucosa. Endemic areas include the Caribbean, Southeast Asia, and South India. Patients present with chronic diarrhea, abdominal discomfort/cramps, progressive weight loss, and clinical features of malabsorption. Patients with tropical sprue can develop megaloblastic anemia (low hemoglobin and elevated MCV) from a deficiency in folate and vitamin B12 absorption. A small bowel biopsy would show blunting of the villi and infiltration of lymphocytes, plasma cells, and eosinophils. Microorganisms may also be seen. Treatment is an oral tetracycline and folic acid for 3-6 months.

McCarroll et al. study the relationship between infectious gastroenteritis and tropical sprue. In a case-control study, the authors found that prior infectious gastroenteritis increased the risk of tropical sprue. The authors recommend treatment of suspected tropical sprue with oral folic acid replacement.

Incorrect Answers:
Answer A: Celiac disease can present similarly to tropical sprue with chronic diarrhea, abdominal pain, and weight loss. A small intestine biopsy can similarly show villous atrophy and a lymphocytic infiltrate, as well as crypt hyperplasia. Celiac disease is an immune response to gluten, while symptoms of tropical sprue are not diet-associated. The development of symptoms following significant travel (lasting at least several weeks) to an endemic country should raise suspicion for tropical sprue.

Answer B: Crohn disease presents with chronic diarrhea, abdominal pain, weight loss, skip lesions anywhere from mouth to anus, extraintestinal manifestations, and signs of malabsorption. A biopsy will show transmural inflammation with noncaseating granulomas, giant cells, and aggregates of lymphocytes in the lamina propria.

Answer C: Giardia is a parasite that is endemic in the tropics and North American mountain regions. Patients present with foul-smelling diarrhea, excessive gas, and nausea. Diagnosis can be confirmed with a stool analysis or immunoassay. Though a biopsy is normally not indicated, it would show mild lymphocytic infiltration and Giardia trophozoites on the intestinal surface.

Answer E: Whipple disease is caused by the bacteria Tropheryma whipplei. Patients present with diarrhea, abdominal pain, and signs of malabsorption. Extraintestinal symptoms such as arthritis are common. A biopsy of the small intestine would show Periodic acid-Schiff (PAS)-positive foamy macrophages in the lamina propria.

Bullet Summary:
Tropical sprue presents with diarrhea, abdominal cramping, weight loss, megaloblastic anemia due to malabsorption, and a small bowel biopsy showing villi blunting following travel to an endemic area such as South Asia or the Caribbean.


Question: A 25-year-old man is brought to the emergency department by paramedics for altered mental status. He was found lying down at a bus stop unresponsive. On arrival, the patient has slurred speech and is somnolent. Further is unable to be elicited. His temperature is 98.0°F (36.7°C), blood pressure is 130/80 mmHg, pulse is 80/min, and respirations are 12/min with a saturation of 97% on room air. Physical exam reveals a sleeping man with miotic pupils. The patient is easily arousable to voice and sternal rub but falls asleep rapidly. He has decreased bowel sounds. He is able to state his name and knows that he is at the hospital and has an otherwise normal neurologic exam. Which of the following is the most appropriate management?

Answer: Observation

Explanation:
This patient's presentation with altered mental status, pinpoint pupils, and decreased bowel sounds is most consistent with an opioid overdose. Given his stable respiratory status and oxygen saturation without notable bradypnea, observation alone until the patient is clinically sober is the most appropriate management.

Opioids are commonly used to treat painful conditions but have the potential to become drugs of abuse. Opioid overdose presents with bradypnea, somnolence, decreased bowel sounds, and pinpoint pupils. Any patient who is not protecting their airway, failing to oxygenate, or failing to ventilate should immediately be given naloxone which rapidly reverses the effect of opioids. However, this precipitates withdrawal which is unpleasant for patients and leads to nausea, vomiting, agitation, and diaphoresis among other findings. For this reason, patients who have overdosed on opioids and are stable can be observed until clinically sober.

Dietze et al. studied the effect of intranasal versus intramuscular naloxone for opioid overdose in a randomized control trial. The authors found that patients who received intranasal naloxone needed a second dose of naloxone more frequently compared to patients who received intramuscular naloxone. The authors recommend further study of optimal dosing and concentration of intranasal naloxone to respond to opioid overdoses outside of the hospital.

Incorrect Answers:
Answer A: Atropine is an appropriate treatment for a cholinergic toxidrome. This would manifest with bronchorrhea, bronchospasm, bradycardia, urinary incontinence, diarrhea, and drooling. Atropine should be administered until respiratory symptoms improve; large doses may be required.

Answer B: Disulfiram inhibits the enzyme acetaldehyde dehydrogenase causing severe nausea, vomiting, and a very ill feeling when a patient drinks alcohol from the accumulation of byproducts. This drug is a second-line agent used to reduce drinking in chronic alcohol use disorder but has no indication in managing acute alcohol intoxication as it is a preventive medication.

Answer C: Flumazenil is the reversal agent for benzodiazepines. Its use has fallen out of favor as it can precipitate seizures in chronic benzodiazepine users. Any patient with a suspected benzodiazepine overdose who is protecting their airway should be observed until clinically sober as there is no need to rapidly reverse them and possibly cause seizures.

Answer D: Naloxone is the antidote of choice in opioid overdose in patients who are not adequately oxygenating, ventilating, or protecting their airway. It is not indicated in opioid overdose in a clinically stable patient as the patient can merely be observed without the unpleasant side effects of immediate withdrawal from naloxone (including vomiting which in some cases could lead to aspiration). This patient is oxygenating well, protecting his airway, and does not have profound bradypnea.

Bullet Summary:
Opioid overdose presents with somnolence, pinpoint pupils, decreased bowel sounds, and bradypnea; stable patients who are adequately breathing and protecting their airway require only observation until clinically sober.


Question: A 55-year-old woman presents to the primary care clinic for her annual visit. She has no complaints and is asymptomatic. She has a history of hypertension, hyperlipidemia, and diabetes. Her medications are lisinopril, amlodipine, atorvastatin, and metformin. There is no family history of malignancy. She is a non-smoker and drinks 3-4 standard drinks per week. Her temperature is 98.2°F (36.8°C), blood pressure is 142/84 mmHg, pulse is 82/min, and respirations are 16/min. On physical exam, a solid, immobile neck mass is palpated inferior to the cricoid cartilage to the left of midline. An ultrasound is obtained and shows a 1.2 cm hypoechoic mass with microcalcifications. Serum thyroid-stimulating hormone (TSH) concentration is 7.2 µU/mL. Which of the following is the most appropriate next step in management?

Answer: Fine needle aspiration

Explanation:
This patient’s presentation with an asymptomatic thyroid nodule with suspicious ultrasound features (≥ 1 cm hypoechoic mass with microcalcifications) and elevated TSH is concerning for thyroid malignancy. The most appropriate next step in management is a fine needle aspiration (FNA).

The first step in the diagnostic work-up of a thyroid nodule, which can be found incidentally in asymptomatic individuals or in the presence of obstructive or vocal symptoms, includes an ultrasound and measurement of serum TSH levels. If TSH is normal or elevated, this suggests a hypofunctioning (“cold”) nodule, which increases the risk of cancer. These nodules should undergo FNA if suspicious sonographic findings are present. Suspicious sonographic findings include irregular margins, microcalcifications, taller-than-wide shape, and rim calcifications in nodules ≥ 1 cm in diameter. If TSH is low, then thyroid scintigraphy (radioiodine scan) should be performed to confirm whether the nodule is hyperfunctioning (“hot”). Hyperfunctioning nodules are rarely cancerous, so these patients can often avoid FNA. Hyperfunctioning nodules such as toxic adenomas which cause overt hyperthyroid symptoms may warrant further treatment with radioiodine, surgery, or anti-thyroid medications.

Durante et al. review the epidemiology and diagnostic approach to thyroid nodules. The authors find that nodules with suspicious sonographic patterns such as solid composition, hypoechogenicity, irregular margins, and microcalcifications should undergo cytological evaluation. The authors recommend molecular testing only in cases in which cytology is indeterminate.

Incorrect Answers:
Answer B: Propylthiouracil is a thionamide that inhibits thyroid peroxidase, thus preventing thyroid hormone synthesis. It can be used for the symptomatic control of hyperthyroidism in toxic adenomas prior to definitive surgical resection. It is not indicated for the treatment of a hypofunctioning nodule.

Answer C: Radioiodine ablation can be used in the treatment of a toxic adenoma, which would take up the radioactive iodine. It is not indicated for the treatment of a hypofunctioning nodule, which would not exhibit radioiodine uptake.

Answer D: Surgical removal of the mass is a treatment option for a malignant thyroid nodule. Although a hypofunctioning nodule is more likely to be malignant, an FNA should be performed first to confirm the diagnosis.

Answer E: Thyroid scintigraphy is used for thyroid nodules with low TSH, which increases the probability of a hyperfunctioning nodule. Confirmation of a hyperfunctioning nodule can help prevent further invasive diagnostic work-up because hyperfunctioning nodules are unlikely to be malignant. Thyroid scintigraphy would not be appropriate in this patient with an elevated TSH.

Bullet Summary:
The next step in management for a thyroid nodule with suspicious sonographic features and an elevated TSH is fine needle aspiration.


Question: A 19-year-old man presents to his primary care physician. He is asymptomatic and has no acute complaints, has no medical problems, and takes no medications. He was born in the United States but moved to El Salvador at age 11 and has only recently moved back to the United States in the past year. He was up to date on his vaccinations prior to his move to El Salvador. He last received a diphtheria, tetanus, and acellular pertussis (DTaP) vaccine 14 years ago at age 5, the second dose of a meningococcal vaccine 3 years ago, and an influenza vaccine 2 months ago. The patient’s temperature is 98.2°F (36.8°C), blood pressure is 120/76 mmHg, pulse is 82/min, and respirations are 16/min. There are no rashes noted on physical exam. Which of the following vaccine regimens is indicated in this patient?

Tetanus, diphtheria, and acellular pertussis

Answer: Tetanus, diphtheria, and acellular pertussis

Explanation:
This patient has recently moved back to the United States after living in another country for several years and is behind on his tetanus, diphtheria, and pertussis vaccine series. The tetanus, diphtheria, and acellular pertussis (Tdap) vaccine is indicated at least once in adults who have not previously received Tdap.

The standard vaccination schedule for tetanus, diphtheria, and pertussis includes a 5-dose childhood vaccine series consisting of DTaP at ages 2 months, 4 months, 6 months, 15-18 months, and 4-6 years. The first booster dose then consists of Tdap at age 11-12, with a tetanus and diphtheria (Td) vaccine every 10 years afterwards. In adults who have not previously received Tdap, a single Tdap dose should be administered regardless of time interval since the last dose of Td. Subsequent Td booster doses should then be given at 10-year intervals. Contraindications to Tdap include prior anaphylaxis after a tetanus, diphtheria, or pertussis vaccine or a history of seizures or encephalopathy within 7 days of receiving a previous pertussis-containing vaccine.

Kerr et al. studied the risk of major birth defects after administering the Tdap vaccine in pregnant patients. The authors found no increase in the risk of malformations in the offspring of pregnant patients that received the Tdap vaccine. The authors recommend the administration of Tdap during pregnancy.

Incorrect Answers:
Answer A: Influenza is incorrect because the influenza vaccine is recommended only once per flu season. This patient already received the flu vaccine during this flu season, so the influenza vaccine is not indicated.

Answer B: Tetanus and diphtheria only are incorrect because the Td vaccine booster is indicated every 10 years in adults who have already received a prior dose of Tdap. In adults who have never received a previous Tdap dose, Tdap is indicated unless contraindications exist.

Answer C: Tetanus, diphtheria, acellular pertussis, and influenza are incorrect because influenza vaccine is not indicated in this patient. This patient has already received a dose of the influenza vaccine during this flu season.

Answer E: Tetanus, diphtheria, and influenza are incorrect because neither the Td nor influenza vaccines are indicated in this patient. The Td vaccine is indicated every 10 years in adults who have already received a prior dose of Tdap. The influenza vaccine is only indicated once per flu season.

Bullet Summary:
The tetanus, diphtheria, and acellular pertussis (Tdap) vaccine is usually administered to adolescents at age 11-12 and is indicated at least once in adults who have not previously received Tdap.


Question: A 66-year-old man presents to the clinic for evaluation of a skin lesion on his hand. The lesion has grown rapidly over the previous 2 weeks. He endorses trauma to the area when he accidentally scraped his hand against a window and notes that there was some bleeding. His medical history is significant for chronic renal failure for which he received a renal transplant 5 years prior, as well as multiple surgeries for skin cancer. His current medications include aspirin, atorvastatin, prednisone, tacrolimus, and mycophenolate mofetil. His temperature is 98.6°F (37°C), blood pressure is 136/91 mmHg, pulse is 82/min, and respirations are 11/min. Physical exam is notable for a 2 x 2.5 cm nodular lesion of the dorsal hand as seen in Figure A. Which of the following is the most likely diagnosis?

Answer: Keratoacanthoma

Explanation:
This patient presents with a rapidly enlarging, well-circumscribed, volcano-like papule with a central keratotic core consistent with the diagnosis of keratoacanthoma.

Keratoacanthomas represent a well-differentiated variant of cutaneous squamous cell carcinoma. They present as a rapidly enlarging skin lesion with a characteristic hyperkeratotic core. Most lesions occur on the sun-exposed areas of the body, especially the head, neck, and extremities. Risk factors for developing a keratoacanthoma include immunosuppression, arsenic exposure, old scars or burns, xeroderma pigmentosum, or exposure to high levels of ionizing radiation. Most keratoacanthomas tend to involute within several months after initial onset; however, surgical excision can be performed because of the histologic similarity to squamous cell carcinoma. Biopsy of lesions with malignant transformation will show atypical keratinocytes and malignant cells, invasion into dermis, and keratin “pearls” on histology.

Kwiek and Schwartz present a review of keratoacanthoma diagnosis and treatment. They discuss how these lesions characteristically exhibit spontaneous regression after rapid growth. They recommend surgical excision as first-line therapy for the lesion.

Figure/Illustration A is a clinical photograph showing a well-circumscribed, dome-shaped papule with a hyperkeratotic core (red circle) consistent with keratoacanthoma.

Incorrect Answers:
Answer A: Basal cell carcinoma is the most common skin cancer in humans. It most commonly presents as a pearly pink papule or ulcer with telangiectasias and a rolled border. Compared to keratoacanthoma, basal cell carcinomas are slow-growing and are only locally invasive. Surgical excision is the treatment of choice for most basal cell carcinomas.

Answer C: Molluscum contagiosum is a common viral infection caused by a poxvirus that is most frequently seen in children. It presents with solitary or multiple umbilicated papules and is spread by person-to-person contact. Immunosuppressed individuals, such as those with HIV/AIDS, may have disseminated molluscum contagiosum, which is highly recalcitrant to treatment.

Answer D: Pyogenic granulomas are vascular proliferations that present as rapidly growing, pink to red, friable papules that are prone to bleeding with minor trauma. They are most commonly seen in children and pregnant women. The oral mucosa is a common area of presentation, although pyogenic granulomas may present in any skin location. Treatment is through mechanical removal via surgical excision, laser ablation, or electrical curettage.

Answer E: Verruca vulgaris is a common viral infection of the skin caused by several subtypes of human papilloma virus (HPV). They present as rough-textured or filiform papules. Close examination may reveal pinpoint areas of red/black, which represent thrombosed blood vessels within the wart. Treatment options for common warts include salicylic acid or cryotherapy; however, recurrence after treatment is common.

Bullet Summary:
Keratoacanthomas presents as rapidly enlarging, well-circumscribed, volcano-like papules with a central hyperkeratotic core.