P429: A case of ibuprofen induced hypersensitivity vasculitis

Hypersensitivity vasculitis is usually represented histopathologically as leukocytoclastic vasculitis or necrotizing vasculitis. There are many potential causes of hypersensitivity vasculitis, such as chronic diseases, infections, or drugs, but it may also be idiopathic. Among them, drugs are the most common cause especially antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs). A 37-year-old man presented with hemorrhagic bullous lesions on his both feet and legs with edema. He had myalgia and began to take ibuprofen 600mg/day which continued for six days. He had no other underlying diseases. Pathologic study showed neutrophil and eosinophil infiltration, endothelial cell swelling, extravasation of erythrocytes, and fibrinoid degeneration. Other studies, including rheumatologic laboratory tests, routine chemistry tests, and viral immunology tests, showed non-specific findings, except for leukocytosis (12740/μL with neutrophilia, 92%), microscopic hematuria and proteinuria. Through these clinical and histopathologic findings, he was diagnosed as ibuprofen induced hypersensitivity vasculitis with renal involvement. He stopped taking ibuprofen and intravenous methylprednisolone daily 125mg was used for 4 days, tapering by 12.5mg every 2 days. Furthermore, he was referred to nephrology for renal involvement work-up and management.