抄録
We report a case of oral ulceration that occurred during the course of rheumatoid arthritis treated with methotrexate. The patient was a 71-year-old man with oral ulceration of the floor of the mouth. The ulcer showed no induration, with a flat, clean surface and no bleeding. Biopsy revealed ulcer formation with marked inflammatory cell infiltration in the submucosa and dysplasia-like changes in epithelium. Topical steroids were ineffective. After reducing the dose of methotrexate, we observed that the lesion had epithelialized. The oral toxicity of low-dose methotrexate therapy is discussed.
