A 17-year-old boy comes to the office due to a skin rash that has been present for a day. One week ago, he had a sore throat that improved with oral penicillin therapy. Skin examination shows several violaceous, raised, nonblanchable lesions distributed over the bilateral lower extremities. Histologic findings of the biopsied rash are shown in the image below. Which of the following is the most likely diagnosis in this patient?

Question

A 17-year-old boy comes to the office due to a skin rash that has been present for a day.  One week ago, he had a sore throat that improved with oral penicillin therapy.  Skin examination shows several violaceous, raised, nonblanchable lesions distributed over the bilateral lower extremities.  Histologic findings of the biopsied rash are shown in the image below.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

Eductional Objective: Cutaneous small vessel vasculitis is associated with medication (eg, penicillins, cephalosporins) use and typically presents with palpable purpura in the lower extremities.  Characteristic histopathologic findings include marked perivascular inflammation of small blood vessels with fibrinoid necrosis and a predominance of neutrophils and fragmented neutrophilic nuclei (leukocytoclastic vasculitis).

A 17-Year-Old Boy Comes to the Office Due to a Skin