Leukocytoclastic vasculitis and interstitial nephritis with carbimazole treatment.

Carbimazole is a common treatment for hyperthyroidism in the UK. Its main side effects include a rash, agranulocytosis and rarely a lupus-like syndrome. Although vasculitis associated with antineutrophil anticytoplasmic antibodies (ANCA) has been reported on several occasions following treatment with propylthiouracil, vasculitis with carbimazole appears to be less common. We report a case of leukocytoclastic vasculitis with carbimazole therapy accompanied by acute renal failure secondary to interstitial nephritis. Interstitial nephritis has previously been reported with propylthiouracil but not carbimazole.