Thyroid crisis following interstitial nephritis.

A 54-year-old man with Graves' disease had been treated with thiamazole (5 mg/day). His thyroid hormone level was increased after exodontia in February 2006. Although his prescribed dose of thiamazole was increased after exodontia on the fourth day, he developed thyroid crisis on exodontia 52 nd day. Laboratory findings also showed renal dysfunction (from Cr 1.0 mg/dL in July 2005 to Cr 1.8 mg/dL on exodontia 37th day). His thyroid hormone level was normalized after subtotal thyroidectomy; however, serum Cr level was still high. He was diagnosed with interstitial nephritis as a result of renal biopsy, and he was treated with prednisolone 30 mg/day. This present case developed thyroid crisis even though the quantity of thiamazole was increased after exodontia. It seems that interstitial nephritis, as well as exodontia, is an aggravation factor of thyroid function. After a poor response to anti-thyroid drugs, it is necessary to prevent thyroid crisis by determining the aggravating factor and to then provide appropriate treatment.