Coalescing purpuric plaques
A 55-year-old woman presented with a three-week history of purpura on her shins. She had no cutaneous or systemic complaints. The patient's medical history was significant only for hypertension, which was controlled by atenolol. Physical examination found her to be otherwise healthy. Laboratory studies for antistreptolysin, hepatitis, and antinuclear antibodies (ANAs) were within normal limits. A stool guaiac test was normal. Biopsy showed inflammation of small blood vessels with “nuclear dust,” fragments of inflammatory cells.
A 35-year-old HIV-positive man presented with purple plaques on his back. His CD4 count was 210/µL. The lesions had developed several months earlier when his CD4 count was much lower. His medications included Combivir (lamivudine/zidovudine) and nelfinavir. A biopsy revealed increased spindle cells with vascular slits. Vascular structures demonstrated endothelial cells with extravasated erythrocytes and hemosiderin-laden macrophages. A guaiac test and abdominal and pulmonary CTs were normal.