Fixed drug eruption induced by indapamide. Cross-reactivity with sulfonamides.

Indapamide is a nontiazidic sulfonamide diuretic which has not been previously reported as a cause of fixed drug eruption. We describe a patient who experienced several episodes of fixed drug eruption during treatment with indapamide. The diagnosis was confirmed by positive controlled oral challenge test. The possible existence of cross-reactivity with other sulfonamide derivatives was investigated by controlled oral challenge test with sulfamethoxazole, sulfadiazine and furosemide, with the tests with sulfamethoxazole and sulfadiazine resulting positive.