• To our knowledge, this is the first histopathologic report of skin eruptions due to oral methazolamide. From the four cases studied, we conclude that there are at least two histopathologic types: one is characterized by perivascular lymphocytic infiltrate with a vacuolar alteration at the dermoepidermal junction, the other by perivascular eosinophils, lymphocytes, and scattered mast cells. There also seem to be at least two patterns of skin eruptions: one maculopapular and the other urticarial. The type of skin eruption and the histopathologic type appear to be related.