Rare adverse effect of a common drug: nitrofurantoin-induced ANCA-associated vasculitis.

Nitrofurantoin is commonly prescribed to treat urinary tract infections (UTI). Reported adverse effects include gastrointestinal, pulmonary, hepatic and neurological disorders. We report a case of a 67-year-old woman treated for UTI with nitrofurantoin who presented with antineutrophilic cytoplasmic antibody (ANCA)-associated renal and skin vasculitis 3 days after starting treatment. The symptoms resolved following withdrawal of the drug and treatment with steroids. This is the first reported case of nitrofurantoin causing ANCA-associated vasculitis.