Methotrexate-Induced Oral Erythema Multiforme: a Case Report

Abstract

Erythema multiforme (EM) is an inflammatory mucocutaneous disorder. It can be triggered by herpes simplex virus infection or adverse drug reaction. Oral EM is characterized by oral mucosal ulcerations and lip lesions without any skin lesions. A 65-year-old man was referred for painful ulcerations covered with necrotic tissue on the vermillion of the upper and lower lips, lateral border of the tongue, and buccal mucosa. Medical history revealed methotrexate treatment for rheumatoid arthritis. Histopathologic analysis showed ulceration areas and moderate to dense perivascular, mainly lymphocytic inflammatory infiltrate. The sudden onset of extensive ulcerations in the oral cavity, a positive drug history, and histopathologic analysis led to the diagnosis of oral EM. Although oral EM is confined to the oral cavity, subsequent attacks can produce more severe forms of EM. Hence, it is important to identify oral EM for early diagnosis, adequate treatment, and follow-up.