Abstract
We report a patient who developed drug-induced hypersensitivity syndrome while on oral carbamazepine and mexiletine therapy. A 56-year-old man with zoster-associated pain began taking mexiletine 12 days after administration of carbamazepine. Maculopapular skin lesions developed on the right thigh and the body temperature rose to around 38°C, 20 days after taking carbamazepine. He quit carbamazepin; however, the skin lesions worsened. He quit mexiletine 2 days after stopping carbamazepine. The white cell count in peripheral blood increased to 11,170/mm3; AST was 105 U/L, and ALT 280 U/L. There were atypical lymphocytes in the peripheral blood. The body temperature decreased after the patient received oral betamethasone 1 mg/day; however, the skin lesions further worsened and covered almost the whole body. He received pulsed intravenous methylprednisolone 1 g/day for 3 days. The body temperature, which once elevated > 39°C, rapidly decreased. The skin lesions gradually resolved. The presence of generalized skin lesions, fever, lymphadenopathy, leukocytosis, and elevated transaminases strongly suggested that the patient developed drug-induced hypersensitivity syndrome to carbamazepine or mexiletine.
