Coagulation Disorders USMLE Step 1 Practice Question
A 28-year-old woman with no significant past medical history presents to the emergency department with spontaneous gingival bleeding and a petechial rash on her lower extremities that appeared over the past 2 days. She reports no fever, no recent viral illness, and denies taking any medications or supplements. Vital signs: BP 118/76 mmHg, HR 88 bpm, RR 16, temperature 37.2°C, SpO2 98% on room air. She has no hepatosplenomegaly and no lymphadenopathy on examination. Laboratory studies show: platelet count 9,000/μL, hemoglobin 13.2 g/dL, WBC 7,200/μL, PT 12 seconds, PTT 34 seconds, fibrinogen 340 mg/dL. Peripheral blood smear shows reduced platelets with normal morphology and no schistocytes. Bone marrow biopsy reveals normal numbers of megakaryocytes with normal maturation and morphology. Which of the following is the most likely diagnosis?
Answer choices
- ADisseminated intravascular coagulation
- BThrombotic thrombocytopenic purpura
- CDrug-induced thrombocytopenia from a herbal supplement
- DAcute leukemia
- EImmune thrombocytopeniaCorrect answer
- FSystemic lupus erythematosus with secondary antiphospholipid syndrome
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