Methotrexate-induced cutaneous ulceration in patients with erythrodermic mycosis fungoides.

Methotrexate-induced cutaneous ulceration has rarely been reported in patients with mycosis fungoides. We report 4 patients with mycosis fungoides who developed cutaneous ulceration as an initial manifestation of methotrexate toxicity. Methotrexate dose at the time of ulceration ranged from 10-60 mg. All 4 patients were erythrodermic, which may have predisposed them to this toxic effect. It is important to recognize cutaneous ulceration as an uncommon, but potentially serious, side effect of methotrexate in these patients, and to differentiate it from ulceration due to progressive lymphoma.