Hypersensitivity syndrome: a rare but severe adverse effect of antithyroiddrugs

We report the case of a female patient with a severe hypersensitivity syndr ome caused by carbimazole. She was treated for Graves' disease for a few we eks when she was referred for skin rash, increased liver enzymes and hypere osinophilia. No immunological abnormalities were detected. Discontinuation of carbimazole resulted in quick recovery. Pathogenesis of the hypersensiti vity syndrome is discussed. Antithyroid drugs are rarely involved in the sy ndrome but cases with vasculitis have been described. In our patient, the r ole of excessive dose is possible.