Introduction: Several cases of vasculitis associated with antineutrophil cytoplasmic antibodies (ANCA) have been reported in patients treated with synthetic anti-thyroid drugs but only 2 cases have incriminated benzylthiouracil.
Observation: A 36 year-old woman, 3 years after treatment with benzylthiouracil, rapidly developed progressive kidney failure, related to a pauci-immune extra-capillary glomerular nephropathy and necrotic vasculitis lesions. The search for p-ANCA was positive with anti-myeloperoxidase specificity.