A Case of Cutaneous Side Effect of Methotrexate Mimicking Behçet's Disease.

Methotrexate (MTX) is an antimetabolite which interferes with DNA synthesis, and it is used for the treatment of moderate to severe psoriasis, atopic dermatitis and a wide variety of cutaneous diseases. Although many adverse effects of MTX, including cutaneous ulcerations, have been documented, multifocal mucosal ulceration mimicking Behçet's disease has not been reported. In our case, a 63-year-old female presented with oral, vaginal ulcer and multiple purpuric patches on both legs. Considering patient's clinical course and histopathologic findings, we presumed that these reactions may be the side effect of MTX administered for treatment of necrotizing scleritis. Herein we report the cutaneous side effect of MTX that manifested clinically like Behçet's disease.