USMLE Step 3
Practice Test 12 for USMLE Step 3: real questions and explanations from the Varsity Tutors practice-test pool.
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A 68-year-old man with chronic kidney disease stage G4 (eGFR 28 mL/min/1.73m²) is admitted for severe cellulitis of the lower leg. He has a history of anaphylaxis to penicillin. The physician plans to start empiric antibiotic coverage for both MRSA and Pseudomonas aeruginosa. Which antibiotic regimen requires the most careful dose adjustment and therapeutic monitoring due to his renal impairment?
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A 68-year-old man with chronic kidney disease stage G4 (eGFR 28 mL/min/1.73m²) is admitted for severe cellulitis of the lower leg. He has a history of anaphylaxis to penicillin. The physician plans to start empiric antibiotic coverage for both MRSA and Pseudomonas aeruginosa. Which antibiotic regimen requires the most careful dose adjustment and therapeutic monitoring due to his renal impairment?
Explanation: Both vancomycin and aminoglycosides (like tobramycin) are primarily cleared by the kidneys and have significant nephrotoxicity and other toxicities (ototoxicity for aminoglycosides). They have narrow therapeutic windows, requiring careful initial dose adjustment based on eGFR and subsequent therapeutic drug monitoring (trough levels) to ensure efficacy and minimize toxicity. The other regimens contain agents that either do not require renal dose adjustment or require less intensive monitoring.
A 12-month-old girl is brought for her well-child visit. Her parents report she is a "picky eater." Her diet consists primarily of whole milk, which she drinks from a bottle throughout the day, totaling about 36 ounces (1080 mL) daily. She eats small amounts of crackers and fruit puree. Physical examination shows a pale and interactive child. Her weight and height are at the 50th percentile.
In addition to dietary counseling, which of the following is the most appropriate next step?
Explanation: This child's history of excessive cow's milk intake (>24 ounces/day) and limited diet of iron-rich foods places her at high risk for iron deficiency anemia. Cow's milk is low in iron, and excessive intake can cause microscopic gastrointestinal bleeding and interfere with iron absorption. The clinical finding of pallor further raises suspicion. Therefore, the most appropriate next step is to screen for anemia with a complete blood count (which would show microcytic anemia) and to assess iron stores with a ferritin level. (B) Children between ages 1 and 2 should drink whole milk for adequate fat for brain development. The issue is the quantity of milk, not its fat content. (C) If the child is iron deficient, an iron supplement is needed, not a multivitamin without iron. (D) While picky eating can be normal, this child's specific dietary pattern has significant medical risks that should not be dismissed.
A 28-year-old competitive runner was diagnosed with a PE two weeks ago. He was started on apixaban and his shortness of breath has resolved. He is hemodynamically stable and eager to resume training. What is the most appropriate advice regarding physical activity?
Explanation: Early ambulation and a gradual return to physical activity are encouraged after an acute PE as soon as the patient is hemodynamically stable and symptoms allow. Prolonged immobility is a risk factor for VTE. The main restriction while on anticoagulation is to avoid activities with a high risk of traumatic injury and bleeding (e.g., contact sports). Therefore, a gradual, sensible return to running is appropriate. Bed rest is contraindicated. An immediate return to full-intensity training without a gradual ramp-up is not advisable.
A 68-year-old woman's first DEXA scan shows a T-score of -2.7 at the lumbar spine and -1.8 at the femoral neck. She has no history of fractures. Her medical history is significant for hypertension, treated with a thiazide diuretic.
Based on these results, what is the most appropriate next step in management?
Explanation: The diagnosis of osteoporosis is made with a T-score of -2.5 or lower at any site (hip, femoral neck, or lumbar spine). This patient's lumbar spine T-score of -2.7 meets the diagnostic criteria for osteoporosis. Therefore, initiation of pharmacologic therapy (e.g., an oral bisphosphonate like alendronate) is indicated to reduce her risk of fracture, in addition to counseling on adequate calcium/vitamin D intake and weight-bearing exercise. Repeating the DEXA scan in a year would unnecessarily delay treatment. Supplementation alone is insufficient for treating established osteoporosis. While thiazides can have a modest beneficial effect on bone density, this does not negate the diagnosis or the need for treatment.
A 55-year-old man with a history of unprovoked PE has been treated with rivaroxaban 20 mg daily for the past 4 months. He is certain he has not missed any doses. He presents to the emergency department with acute pleuritic chest pain. A CT angiogram confirms a new segmental PE. What is the most appropriate next step in management?
Explanation: A recurrent PE while on a therapeutic dose of a direct oral anticoagulant (DOAC) constitutes a treatment failure. The standard of care in this situation is to switch to a different class of anticoagulant, with low-molecular-weight heparin (LMWH) being the preferred agent. LMWH provides reliable anticoagulation and has a different mechanism of action. Increasing the rivaroxaban dose to the initial loading dose is not an evidence-based strategy for treatment failure. An IVC filter is only indicated if there is a contraindication to all forms of anticoagulation. Adding aspirin increases bleeding risk without established benefit for VTE treatment failure.
A 45-year-old man with recently diagnosed schizophrenia, paranoid type, is being discharged from his first psychiatric hospitalization. He was stabilized on a long-acting injectable antipsychotic. He is unemployed, has no family support, and will be living in a transitional housing program. The inpatient team is developing a discharge plan to minimize the risk of relapse and re-hospitalization.
Which of the following is the most critical component to include in this patient's discharge plan?
Explanation: Assertive Community Treatment (ACT) is an evidence-based, intensive, team-based service model designed for individuals with severe mental illness who are at high risk of relapse and have difficulty engaging in traditional outpatient services. Given the patient's new diagnosis, lack of social support, and housing situation, an ACT team can provide comprehensive, wrap-around services including case management, medication administration, and therapy in the community, which is the most critical intervention to ensure continuity of care and prevent re-hospitalization. While other options are beneficial, the ACT program provides the necessary intensive, coordinated support structure for this high-risk transition.
HPI/PP Visit: 22F G1P1, 6 weeks postpartum, exclusively breastfeeding, amenorrheic. She wants to rely on lactational amenorrhea method (LAM) and asks criteria for effectiveness. Infant feeds every 4 hours at night; she occasionally pumps and bottle-feeds. Interpregnancy: wants to avoid pregnancy for 1 year. What counseling should be provided to this patient regarding interpregnancy care?
Explanation: This question tests understanding of postpartum and interpregnancy care within the context of obstetrics and gynecology for USMLE Step 3. Postpartum care involves managing the recovery of the mother, addressing complications, and planning for future pregnancies. Key elements include physical recovery, mental health, and family planning. This case involves specific postpartum challenges such as reliance on lactational amenorrhea for contraception. The clinical scenario highlights the need for counseling on LAM criteria. The correct answer is based on WHO guidelines which recommend LAM is effective only with exclusive frequent feeds and under 6 months in such situations to ensure optimal patient outcomes. A common distractor might suggest LAM effective until first postpartum menses regardless of feeding, which fails to address the key aspect of care by overlooking feeding requirements. To teach this concept effectively, emphasize evidence-based guidelines and integrate patient-centered care approaches. Encourage practice in evaluating postpartum care needs through simulated case studies and reviewing current guidelines.
A 67-year-old man with stable angina who is a former smoker with a 40-pack-year history is on optimal medical therapy. As part of his ongoing care, you discuss appropriate cancer screening. He had a normal colonoscopy 2 years ago.
In addition to age-appropriate cancer screening, which of the following screening tests is specifically indicated for this patient?
Explanation: When evaluating an older male patient with cardiovascular risk factors, you need to consider screening recommendations based on specific risk profiles and evidence-based guidelines. This 67-year-old man with a significant smoking history (40 pack-years) and cardiovascular disease warrants screening for abdominal aortic aneurysm (AAA). The U.S. Preventive Services Task Force recommends one-time AAA screening with abdominal ultrasound for men aged 65-75 who have ever smoked. This patient fits these criteria perfectly - he's 67 and is a former smoker. AAA screening is particularly important because rupture carries extremely high mortality, but elective repair has good outcomes when aneurysms are detected early. Answer A is incorrect because low-dose CT chest screening is recommended for current smokers or those who quit within 15 years, aged 50-80, with 20+ pack-year history. As a "former smoker," we don't know his quit timeline, making this less definitively indicated than AAA screening. Answer B is wrong because PSA screening remains controversial with mixed recommendations. The USPSTF gives it a "C" recommendation (selective screening after discussion), making it less clearly indicated than AAA screening. Answer C is incorrect because carotid duplex screening isn't routinely recommended for asymptomatic patients, even those with cardiovascular risk factors, due to lack of evidence for improved outcomes. Remember for Step 3: Focus on well-established, evidence-based screening guidelines rather than "nice to have" tests. AAA screening has clear criteria and strong evidence for benefit in high-risk populations like older male smokers.
A 66-year-old woman with HFrEF (LVEF 35%) is stable on GDMT and is in sinus rhythm with a heart rate of 72 bpm. Her blood pressure is 110/70 mmHg. She has no contraindications to any medications. Her current regimen includes carvedilol 12.5 mg twice daily, lisinopril 20 mg daily, and spironolactone 25 mg daily. Which of the following medication adjustments is the next priority?
Explanation: The foundational principle of HFrEF management is to titrate evidence-based medications to their target doses as tolerated. This patient is on a sub-target dose of her beta-blocker (carvedilol 12.5 mg bid, target 25 mg bid). Before adding new classes of drugs, it is essential to optimize the doses of the foundational therapies (ACEi/ARB/ARNI, beta-blocker, MRA). Her blood pressure and heart rate allow for up-titration of carvedilol. Switching to an ARNI (B) or adding an SGLT2 inhibitor (C) are appropriate steps, but typically after foundational drugs are at or near target doses. Ivabradine (D) is not indicated as her heart rate is <70 bpm and her beta-blocker is not yet at the maximum tolerated dose.
A 70-year-old man is two hours into his outpatient hemodialysis session. The nurse reports that he is complaining of dizziness and nausea. His blood pressure has dropped from 150/85 mm Hg to 88/52 mm Hg. The ultrafiltration goal for the session is 3.5 liters. Which of the following is the most appropriate initial intervention?
Explanation: Intradialytic hypotension is a common complication of hemodialysis, primarily caused by rapid fluid removal exceeding the plasma refilling rate. The immediate management involves two key steps: first, reducing or temporarily stopping ultrafiltration to halt further volume loss, and second, rapidly expanding the intravascular volume with an intravenous bolus of isotonic crystalloid (e.g., 100-250 mL of normal saline). Placing the patient in the Trendelenburg position is also helpful. Albumin is a second-line agent for refractory cases. Stopping the session is premature, and midodrine is an oral agent used for prevention, not acute treatment.
A 29-year-old woman with recurrent major depressive disorder has been in remission for 9 months on escitalopram 20 mg daily. She reports that her mood is excellent, but she is very distressed by anorgasmia, which began shortly after starting the medication. She states this is causing significant strain in her relationship. She is hesitant to change medications because this is the first one that has worked for her.
Which of the following is the most appropriate next step in management?
Explanation: The correct answer is C. SSRI-induced sexual dysfunction is a common and distressing side effect. For a patient who has responded well to the SSRI and wishes to continue it, augmentation with bupropion is a first-line strategy. Bupropion is a norepinephrine-dopamine reuptake inhibitor that often improves sexual function and can also augment the antidepressant effect. Reassurance (A) is inappropriate as the side effect has persisted for 9 months. Switching to venlafaxine (an SNRI) (B) is unlikely to help, as SNRIs also have high rates of sexual dysfunction. Drug holidays (D) are not recommended for antidepressants with intermediate half-lives like escitalopram and can lead to withdrawal symptoms or breakthrough depression.
Which interdisciplinary team member should be consulted for this aspect of the patient's care?
Explanation: This question tests the management of chronic pediatric conditions, specifically focusing on long-term care strategies and coordination with interdisciplinary teams. Chronic conditions like type 1 diabetes in teens can involve psychosocial issues like disordered eating, requiring mental health support. In this vignette, intentional insulin omission for weight control signals an eating disorder risk needing specialized intervention. Choice A is correct because consulting a mental health specialist addresses diabulimia per ADA recommendations. Choice B is incorrect because orthopedic evaluation isn't indicated without neuropathy evidence. To help students: Emphasize screening for psychosocial complications in diabetes. Practice identifying red flags for referral in adolescent care.
A 30-year-old G1P1 presents to her primary care physician 2 months after an uncomplicated delivery with a 3-week history of progressive dyspnea on exertion, orthopnea, and bilateral lower extremity edema. Her pregnancy was normotensive. Her blood pressure is 110/70 mm Hg, heart rate is 115/min, and respiratory rate is 24/min. Lung auscultation reveals bibasilar crackles. Jugular venous distention is noted.
Explanation: The patient's presentation of new-onset heart failure symptoms (dyspnea, orthopnea, edema, crackles, JVD) in the late postpartum period is highly suspicious for peripartum cardiomyopathy (PPCM). PPCM is an idiopathic cardiomyopathy that presents with heart failure secondary to left ventricular systolic dysfunction towards the end of pregnancy or in the months following delivery. An echocardiogram is the gold standard diagnostic test, as it will directly visualize cardiac chambers, assess systolic and diastolic function, and quantify the ejection fraction, which is characteristically reduced in PPCM. (A, D) A D-dimer or V/Q scan would be used to evaluate for pulmonary embolism, which can present with dyspnea but is less likely to cause the full constellation of heart failure signs seen here. (B) A chest X-ray would be suggestive, likely showing cardiomegaly and pulmonary venous congestion, but it is not as specific or definitive as an echocardiogram for evaluating cardiac function.
HPI/PP Infection: 30F G1P1, 9 days postpartum after prolonged labor and vacuum-assisted delivery, presents with fever 38.7°C, uterine tenderness, and malodorous lochia. Breastfeeding. PMH: none. Vitals: HR 118. Exam otherwise normal. Interpregnancy: asks if infection affects future fertility. What is the most appropriate next step in management for this patient?
Explanation: This question tests understanding of postpartum and interpregnancy care within the context of obstetrics and gynecology for USMLE Step 3. Postpartum care involves managing the recovery of the mother, addressing complications, and planning for future pregnancies. Key elements include physical recovery, mental health, and family planning. This case involves specific postpartum challenges such as fever, uterine tenderness, and malodorous lochia. The clinical scenario highlights the need for antibiotic treatment for endometritis. The correct answer is based on ACOG guidelines which recommend beginning broad-spectrum antibiotics for postpartum endometritis in such situations to ensure optimal patient outcomes. A common distractor might suggest providing reassurance and encouragement of hydration only, which fails to address the key aspect of care by delaying treatment of infection. To teach this concept effectively, emphasize evidence-based guidelines and integrate patient-centered care approaches. Encourage practice in evaluating postpartum care needs through simulated case studies and reviewing current guidelines.
History & Lifestyle: 25-year-old woman presents for preventive care. • Sexually active; no prior cervical cancer screening. • No immunocompromising conditions. • No DES exposure. • Not pregnant. Family History: Aunt with breast cancer; no cervical cancer. Preventive Care Review: Asks when she should start Pap testing and how often. Exam unremarkable.
What preventive measure is most appropriate for the patient's age group?
Explanation: This question tests understanding of preventive care and screening in primary care (USMLE Step 3). Preventive care involves applying evidence-based guidelines to recommend appropriate screenings and lifestyle modifications. In this vignette, the 25-year-old woman has no prior cervical screening, the most appropriate measure is cervical cytology every 3 years, aligning with USPSTF guidelines. Choice A is correct because it matches USPSTF recommendations for cytology every 3 years from ages 21-29. Choice D is incorrect because it suggests no screening until age 30, but screening starts at 21. For teaching, emphasize the importance of staying updated with guidelines, identifying patient-specific risk factors, and prioritizing screenings that provide the greatest benefit. Encourage students to practice applying guidelines in varied scenarios to build confidence in clinical decision-making.
A 67-year-old woman with a 6-year history of Parkinson's disease is experiencing bothersome constipation and early satiety. She has a bowel movement only once every 4-5 days, with significant straining. These symptoms are causing her more distress than her mild tremor. Her medications are carbidopa/levodopa and selegiline. She has tried increasing fiber and water intake with minimal benefit.
Which of the following is the most appropriate next step in managing her gastrointestinal symptoms?
Explanation: Constipation and gastroparesis are very common and often disabling non-motor symptoms of Parkinson's disease, resulting from autonomic dysfunction affecting the enteric nervous system. After lifestyle measures fail, the first-line pharmacologic treatment is an osmotic laxative, such as polyethylene glycol. Selegiline is an MAO-B inhibitor and lacks significant anticholinergic effects that would cause constipation. A colonoscopy is not indicated in the absence of red flag symptoms (e.g., bleeding, anemia, marked weight loss) as constipation is an expected feature of her known disease. Metoclopramide is a dopamine antagonist and is contraindicated in Parkinson's disease as it can acutely worsen motor symptoms.
A 50-year-old woman is admitted to the burn ICU with 60% total body surface area full-thickness burns after a house fire. She required escharotomies of her chest and limbs. Over the first week, she remains hemodynamically unstable, develops acute kidney injury, and remains ventilator-dependent. The family asks about the biggest threat to her life over the next several weeks.
Assuming she survives the initial resuscitation phase, which of the following represents the most significant cause of mortality in the subsequent weeks?
Explanation: After the initial 48-72 hours of resuscitation from burn shock, the leading cause of death in patients with major burns is infection. The loss of the skin barrier, the presence of necrotic tissue, and the systemic immunosuppression associated with severe burns create an extremely high risk for invasive bacterial and fungal infections originating from the wounds. These infections frequently lead to sepsis and multisystem organ failure. While renal failure (A) is a serious complication, it is often a consequence of sepsis. Contractures (B) are a long-term morbidity issue, not a primary cause of mortality. Psychological trauma (D) is a critical component of recovery but not a cause of death in the acute/subacute phase.
A 58-year-old African American man with a family history of prostate cancer in his father at age 68 presents for his annual exam. He is asymptomatic. He has read about PSA testing and asks if he should have it done.
What is the most appropriate next step?
Explanation: For men aged 55 to 69 years, the USPSTF gives a Grade C recommendation for prostate cancer screening with PSA, meaning the decision should be individualized. The most appropriate action is for the primary care physician to engage in shared decision-making, discussing the potential benefits (small reduction in mortality) and harms (false positives, overdiagnosis, complications of treatment) to help the patient make an informed choice that aligns with his values and preferences. His risk factors (age, race, family history) make this conversation particularly important.
A 59-year-old woman on maintenance hemodialysis for 4 years has the following laboratory results: serum calcium 8.4 mg/dL (normal 8.5-10.5), serum phosphorus 7.2 mg/dL (normal 2.5-4.5), and intact parathyroid hormone (PTH) 1100 pg/mL (normal for ESRD <600). She is on a stable dose of sevelamer. Despite dietary counseling, her phosphorus and PTH levels remain elevated. Which of the following is the most appropriate addition to her regimen?
Explanation: This patient has severe secondary hyperparathyroidism, a component of chronic kidney disease-mineral and bone disorder (CKD-MBD), characterized by hyperphosphatemia and markedly elevated PTH. After optimizing phosphate binders and diet, the next step is to target the parathyroid gland directly. Cinacalcet is a calcimimetic that increases the sensitivity of the calcium-sensing receptors on the parathyroid gland to calcium, thereby decreasing PTH secretion without increasing serum calcium or phosphorus. Active vitamin D analogs (like calcitriol or paricalcitol) could also be used, but they can increase calcium and phosphorus absorption, which is undesirable here. Cholecalciferol is an inactive form of vitamin D. Parathyroidectomy is reserved for refractory cases. IV calcium would worsen hyperphosphatemia.
A 5-year-old girl with a history of hypoplastic left heart syndrome who completed a Fontan procedure at age 3 is seen for follow-up. She is clinically well, with stable oxygen saturations of 90-94% on room air. Her parents ask about the primary health concerns she will face as she gets older because of her unique circulation.
The physician should counsel the parents that this patient is at a significantly increased long-term risk for which of the following conditions?
Explanation: When evaluating long-term complications in patients with Fontan circulation, focus on how the altered hemodynamics affect organ systems over time. The Fontan procedure creates a single-ventricle circulation where systemic venous return flows passively to the pulmonary arteries without a pumping chamber, resulting in chronically elevated central venous pressures. The correct answer is D because chronic liver disease and fibrosis represent the most significant long-term risk in Fontan patients. The persistently elevated central venous pressure (typically 12-15 mmHg compared to normal 2-8 mmHg) causes chronic hepatic congestion. This leads to progressive liver fibrosis, cirrhosis, and eventually hepatocellular carcinoma in some patients. This complication, known as Fontan-associated liver disease (FALD), affects nearly all long-term Fontan survivors and is now a leading cause of morbidity and mortality in this population. Option A is incorrect because progressive aortic stenosis isn't a characteristic complication of Fontan circulation. Option B is wrong because Fontan patients typically develop polycythemia (increased red blood cells) due to chronic mild hypoxemia, not iron-deficiency anemia. Option C is incorrect because while endocarditis risk exists in congenital heart disease, it's not the primary long-term concern specific to Fontan circulation compared to liver disease. Remember that Fontan physiology creates a high-pressure, low-flow venous system. When you see Fontan follow-up questions, immediately think about complications related to elevated venous pressures: liver disease, protein-losing enteropathy, arrhythmias, and thromboembolism. Liver disease is the most universal and progressive of these complications.
A 48-year-old woman weighing 150 kg (BMI 51 kg/m²) is being treated for an unprovoked pulmonary embolism. The medical team is selecting an oral anticoagulant for her long-term management. Which of the following is the most appropriate consideration?
Explanation: When treating venous thromboembolism in patients with extreme obesity (BMI >40 kg/m² or weight >120 kg), you need to consider how body weight affects anticoagulant dosing and monitoring capabilities. Warfarin remains the preferred choice for morbidly obese patients because it can be precisely monitored and dose-adjusted using INR values, regardless of body weight. The INR directly measures the anticoagulant effect, allowing clinicians to ensure therapeutic levels are maintained even in patients with altered drug distribution due to extreme obesity. Choice A is incorrect because fixed-dose direct oral anticoagulants (DOACs) like apixaban haven't been adequately studied in patients weighing >120 kg. The standard fixed doses may provide subtherapeutic levels in morbidly obese patients, potentially leading to treatment failure. Choice B is wrong because low-molecular-weight heparin is typically used for short-term or bridging therapy, not long-term management. It's also impractical for extended outpatient use due to the need for daily injections. Choice C is incorrect because dabigatran, like other DOACs, lacks sufficient data in extreme obesity. While it's true that dabigatran has less weight-based dosing variation than some other drugs, there's still concern about adequate drug exposure in patients >120 kg, and unlike warfarin, you cannot monitor its anticoagulant effect with routine lab tests. Remember: In extreme obesity (BMI >40 or weight >120 kg), choose anticoagulants that allow therapeutic monitoring. Warfarin's ability to be monitored with INR makes it the safest choice when DOAC efficacy data is limited.
A 33-year-old man with a history of intravenous heroin use is being prepared for transfer from the ICU to the ward. He was treated for tricuspid valve endocarditis and completed 4 weeks of a planned 6-week course of IV nafcillin. He is medically stable and afebrile. He becomes angry when told he needs two more weeks of IV antibiotics and states he is leaving the hospital against medical advice (AMA).
Which of the following is the most appropriate next step for the physician?
Explanation: When a patient wishes to leave AMA, the physician's first responsibility is to ensure the patient has decision-making capacity. This involves assessing their ability to understand the risks, benefits, and alternatives of treatment (including leaving) and to communicate a choice. Exploring the patient's reasons for wanting to leave can also reveal barriers to care that may be addressable. A psychiatric hold is not appropriate unless the patient is a danger to self or others due to a psychiatric condition. Arranging OPAT is a potential option, but only after capacity is confirmed and a shared decision-making process occurs. Using financial threats is coercive and unethical.
A 39-year-old woman with ileocolonic Crohn disease has persistent fatigue. Her hemoglobin is 9.8 g/dL and MCV is 75 fL. Her ferritin is 10 ng/mL (normal >30 ng/mL) and transferrin saturation is 8% (normal 20-50%). She has been taking oral ferrous sulfate for 3 months without improvement in her anemia or symptoms. Her fecal calprotectin is 650 mcg/g (normal <50 mcg/g).
Which of the following is the most appropriate next step in management?
Explanation: When you encounter iron deficiency anemia in inflammatory bowel disease patients, you need to distinguish between simple iron deficiency and iron deficiency secondary to active inflammation. The key is recognizing that untreated inflammation prevents effective iron absorption and utilization, making iron supplementation futile until the underlying disease is controlled. This patient has classic iron deficiency anemia (low hemoglobin, low MCV, low ferritin, low transferrin saturation) but the critical clue is her markedly elevated fecal calprotectin of 650 mcg/g. Calprotectin is a biomarker of intestinal inflammation - normal levels are under 50 mcg/g, and her level indicates severely active Crohn disease. The failure to respond to 3 months of oral iron therapy despite appropriate supplementation confirms that active inflammation is blocking iron absorption and utilization through hepcidin-mediated mechanisms. Option D is correct because controlling the underlying Crohn disease inflammation is essential before iron therapy can be effective. Without treating the active disease, any form of iron supplementation will likely fail. Option A (IV iron) might seem logical since oral iron failed, but IV iron won't work effectively while severe inflammation persists. Option B (transfusion) isn't indicated - her hemoglobin of 9.8 g/dL, while low, doesn't meet transfusion thresholds in a stable patient. Option C (higher oral iron dose) ignores that absorption is impaired due to inflammation, not inadequate dosing. Remember: In IBD patients with refractory iron deficiency anemia, always check inflammatory markers. Treat the inflammation first, then reassess iron status.
A 29-year-old woman of East Asian descent presents with a 3-month history of fatigue, low-grade fevers, and arthralgias. She also reports pain and weakness in both arms when she blow-dries her hair or carries groceries. On examination, her blood pressure is 160/95 mmHg in the right arm but unobtainable by cuff in the left arm. Bruits are audible over both subclavian arteries. Her erythrocyte sedimentation rate is 95 mm/hr. Which of the following is the most likely diagnosis?
Explanation: This patient's presentation is classic for Takayasu arteritis, a large-vessel vasculitis that primarily affects the aorta and its major branches. It typically occurs in women younger than 50, often of Asian descent. The clinical picture includes systemic constitutional symptoms (fever, fatigue), evidence of vascular inflammation (elevated ESR), and signs of vessel stenosis such as blood pressure discrepancies between limbs, arterial bruits, and limb claudication. Giant cell arteritis affects patients >50. FMD does not cause systemic inflammation. Polyarteritis nodosa is a medium-vessel vasculitis that typically spares the aorta.
A 29-year-old woman with epilepsy since childhood is transitioning from pediatric neurology to adult care. Background: On levetiracetam; seizure-free 2 years; wants to drive; starting pregnancy planning. Current status/Plan: Needs counseling on folic acid, teratogenic risks, and driving laws; periodic drug level checks not routinely needed for levetiracetam. Team: Pediatric neurologist, adult neurologist, PCP, OB/GYN, care coordinator. Coordination: Adult neurology requests prior EEG/MRI and seizure history; PCP to coordinate preventive care. Transition plan: Patient wants minimal visits. Which strategy best supports the patient's transition from pediatric to adult care?
Explanation: This question tests the ability to manage care coordination and transitions in primary care as per USMLE Step 3 standards. Effective care coordination involves seamless communication among healthcare providers and ensuring continuity of care, which is crucial for patient safety and reducing readmissions. In the given scenario, the patient's transition plan must include specific follow-up actions like shared summaries and combined counseling, with responsibilities clearly assigned to prevent gaps in care during this epilepsy transition. The correct answer demonstrates the application of these principles by ensuring appropriate follow-up and clear communication among the care team through patient-centered planning. A common distractor might suggest stopping meds or delaying transfer, which often leads to fragmentation of care and seizure risks. Teaching strategies include reinforcing the importance of clear documentation, regular team meetings, and involving the patient in the care plan to ensure adherence and satisfaction. Encourage students to practice scenario-based planning to visualize transitions effectively, emphasizing reproductive counseling in neurology.