Metformin-induced systemic vasculitis: A rare case report and literature review

Abstract

Leukocytoclastic vasculitis is a cutaneous small-vessel vasculitis characterized by inflammation and necrosis of the vessel wall. It is usually limited to the skin but may rarely affect organs such as the kidney. A 58-year-old female patient presented with palpable petechiae-purpura on the skin after initiating metformin for type 2 diabetes mellitus. Renal biopsy was performed due to hematuria and proteinuria. The renal biopsy showed proliferative glomerulonephritis. After other causes of vasculitis were excluded, a diagnosis of metformin-induced vasculitis was considered. The patient was started on methylprednisolone and azathioprine treatment. Skin findings disappeared completely after two months, and glomerulonephritis resolved at 9 months.