Pemphigus vulgaris with psoriasis vulgaris successfully treated with methotrexate and low-dose methylprednisolone.

Psoriasis and pemphigus are clinically well-characterized chronic, inflammatory skin diseases. Many case reports have described the coexistence of psoriasis and bullous pemphigoid. However, the present report is about a rare case of pemphigus vulgaris in a patient with psoriasis vulgaris. We had a 68-year-old male psoriatic patient who developed blisters lesions and erosions on the trunk and extremities. The histopathology of a blister lesion showed the intraepidermal blisters that contained serous fluid and inflammatory cells. Both of desmoglein core protein 1 antibody and desmoglein core protein 3 antibody were detected. Diagnoses of pemphigus vulgaris and psoriasis vulgaris were made. The patient was treated with methotrexate (12.5 mg/week) and methylprednisone (16 mg/day) after his admission. Two weeks after admission, the patient's lesions gradually subsided. This case reminds us that the therapeutic effect of pemphigus vulgaris may be related to the incidence of psoriasis.