Series Editor: Herbert L. Fred, MD

Prepared by Judith R. Curtis, BS, Medical Student, and Daniel J. Sheehan, MD, Assistant Professor, Division of Dermatology, Medical College of Georgia, Augusta

Recurring Palpable Purpura
A 45-year-old nursing home attendant presented with recurring palpable purpura on her lower extremities (Figure). Her previous work-up, including an HIV test, hepatitis panel, complete blood cell count, and comprehensive metabolic panel, had negative or normal results. On this occasion, she had bilateral purpuric bullous papules and plaques on her legs. A punch biopsy showed leukocytoclastic vasculitis. A culture from a furuncle on her thigh grew methicillin-susceptible Staphylococcus aureus. After treatment with cephalexin, indomethacin, and mupirocin ointment, the furuncle and purpuric lesions improved.

Points to remember: Leukocytoclastic vasculitis (LCV) is an inflammatory condition involving small cutaneous vessels. The pathogenesis involves immune complex deposition followed by cellular infiltrates, cytokine release, and vessel damage. It normally presents as palpable purpura, which may ulcerate or coalesce to form plaques. A biopsy revealing neutrophilic infiltrates with fibrinoid necrosis of the small- to medium-sized blood vessels establishes the diagnosis of LCV.

The etiology is often unknown, but certain drugs, infections, and connective tissue diseases have been implicated. Our patient’s lesions most likely were triggered by a cutaneous bacterial infection. A work-up for systemic involvement is indicated. Treatment ranges from removal of the identifiable cause to administration of anti-inflammatory and immunosuppressive agents

Diagnosis: Leukocytoclastic vasculitis.