A 39-year-old man with human immunodeficiency virus (HIV) infection was referred for evaluation of generalized cutaneous lesions with a 2-week history of fever and malaise. In the last 3 days of that period, widespread papules and nodules appeared over his face, trunk, arms, and legs. Some were ulcerated and covered with thick hemorrhagic crusts (Figure 1). No mucosal lesions were seen. The patient's last CD4 lymphocyte count was 520/μL (to convert to × 109/L, multiply by 0.001), and the viral load was undetectable. He was receiving highly active antiretroviral treatment with combinations of lopinavir-ritonavir and emtricitabine–tenofovir disoproxil fumarate (standard dosage, 300 mg/d), but adherence was poor. A skin biopsy specimen was taken from a representative lesion on the arm for histologic examination (Figure 2 and Figure 3).