(BMJ)—A 3-year-old girl presented with a 1-month hx of progressive discoloration at the tip of her R index finger. No hx of injury or insect bite; no pain, pruritus, or paresthesia. Parents reported that the girl habitually rubbed her scalp with this finger. Exam: brown patch on tip of R index finger. No discoloration on other fingers, oral mucosa, teeth, or eyes. Finger range of motion normal. Application of 75% ethanol didn’t affect the discoloration. What’s the dx?

Acral nevus
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Pernio
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Exogenous staining
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Frictional dermatitis
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Buerger disease
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(BMJ)—A man in his 50s presented with a 2-week hx of a large bruise on his L foot and a 2-month hx of a rash on his bilateral lower limbs. PMHx: HCV treated 3 years earlier; HIV on antiretrovirals; remote hx of alcohol and injection drug use. No trauma/fever/night sweats/weight loss/other bleeding. Exam: poor dentition, no effusion of L ankle. Labs: low Hgb; WBC/platelets/mean corpuscular volume, WNL. What’s the dx?

Vitamin B12 deficiency
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Henoch-Schönlein purpura
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Scurvy
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Meningococcal septicemia
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Idiopathic thrombocytopenic purpura
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