Fixed drug eruption caused by sulfaguanidine.

We report a patient who developed a fixed drug eruption (FDE) due to sulfaguanidine. This drug has not been previously implicated as a cause of FDE. The diagnosis was confirmed by an oral provocation and a biopsy of the lesion. Oral provocations with other sulfonamides, sulfamethoxazole and sulfadiazine, were well tolerated.