Immunoglobulin A (IgA) pemphigus is an autoimmune bullous disease with IgA deposition between epidermal cells. A 43-year-old man visited our department because of an eating disorder caused by tongue pain. He had a history of hepatic steatosis, and there was no remarkable family history. Seven days after presentation, herpetic stomatitis spread throughout the gum area, and he was hospitalized. Seven days after admission, folliculitis-like findings were noted in the chest, abdomen, back, and trunk, accompanied by clinically significant skin folliculitis in both groin areas. Therefore, Behcet's disease was suspected. He was referred to the department of dermatology, and a pathological biopsy of the groin area was performed on the same day. A direct immunofluorescence test was positive for anti-epidermal cell membrane antibodies (IgA). The patient was therefore given a diagnosis of IgA pemphigus. Prednisolone was administered orally, and the intraoral symptoms improved 12 days after hospitalization. Subsequently, the generalized folliculitis improved 17 days after hospitalization, and he was discharged from the hospital.
