Allopurinol-Induced Leukocytoclastic Vasculitis With Systemic Inflammatory Response: A Case Report From Azerbaijan.

Allopurinol is a commonly prescribed xanthine oxidase inhibitor used in the management of hyperuricemia and gout. Although generally well tolerated, it is associated with rare but potentially life-threatening hypersensitivity reactions, including allopurinol-induced vasculitis. We present the case of a 66-year-old woman who developed an acute cutaneous eruption 14 days after initiating allopurinol 100 mg daily for the management of recurrent gout. She subsequently developed systemic inflammatory manifestations, hepatic involvement, hematologic abnormalities, and immunologic activation consistent with drug-induced vasculitis following exposure to allopurinol. Laboratory findings demonstrated marked elevation of inflammatory markers, liver enzymes, immunoglobulin E levels, and evolving hematologic changes, including eosinophilia followed by lymphocytosis. The patient required plasmapheresis as part of management. This case highlights the importance of early recognition of drug-induced vasculitis and the need for prompt intervention to prevent progression to severe systemic complications.