Leukocytoclastic Vasculitis: An Early Skin Biopsy Makes a Difference.

Leukocytoclastic vasculitis (LCV) is an uncommon condition with a broad differential diagnosis. Although the clinical history, physical examination, and laboratory workup are pivotal when formulating a differential diagnosis of LCV, a skin biopsy is required in most cases to elucidate the cause. The diagnostic yield of a skin biopsy increases within the first 24 to 48 hours of the lesion onset indicating the importance of obtaining a prompt skin sample. We present the case of a 60-year-old man who presented to the emergency department with a three-day history of fevers, headaches, and a painful skin rash. He endorsed rhinorrhea and sore throat a week ago. Physical examination was notable for an erythematous papular rash with palpable violaceous purpura located mainly at the distal right leg and thigh. He also complained of painful bilateral hand edema. His complete blood count and chemistries were unremarkable. His C-reactive protein was 147 mg/L (normal value <8 mg/L), and sedimentation rate was 51 mm (normal value <15 mm). Immunoglobulin A was 509 mg/dL (normal value 82-460 mg/dL). Further workup including viral hepatitis serologies, antinuclear antibodies, complements, antineutrophil cytoplasmic antibodies, cryoglobulins, rheumatoid factor, and blood cultures yielded negative results. Therefore, it was believed that his rash was likely associated with his recent upper respiratory infection. A skin biopsy done on the first day of admission was positive for LCV without immunoglobulin A deposition. He was managed with prednisone and anti-inflammatory medications with improvement of his rash.