Vascular Disease USMLE Step 1 Practice Question
A 28-year-old woman with no significant past medical history presents to the emergency department with acute onset severe bilateral lower extremity pain and cyanosis. She reports a 2-day history of fever, headache, and neck stiffness that preceded the leg pain by 12 hours. Vital signs: BP 92/58 mmHg, HR 118 bpm, RR 22/min, temperature 38.9°C. Physical examination reveals bilateral absent femoral pulses, cyanosis of both feet, and a petechial rash on the trunk and extremities. Neurologic examination shows neck stiffness. Laboratory studies show: D-dimer 8.2 μg/mL (normal <0.5), fibrinogen 95 mg/dL (normal 200–400), platelets 65,000/μL (normal 150,000–400,000), PT/INR elevated, aPTT elevated, and hemoglobin 10.2 g/dL. Bilateral femoral artery duplex shows absent flow. Which of the following is the most likely diagnosis?
Answer choices
- AAntiphospholipid syndrome with acute arterial thrombosis
- BAcute thrombotic thrombocytopenic purpura
- CMeningococcal septicemia with disseminated intravascular coagulationCorrect answer
- DSpontaneous bilateral aortoiliac dissection
- EPolyarteritis nodosa with acute arterial occlusion
- FWarfarin-induced skin necrosis from occult malignancy
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