A case of severe stomatitis associated with pancytopenia that developed during methotrexate therapy for rheumatoid arthritis

Abstract

Methotrexate (MTX) has become the primary drug used to treat rheumatoid arthritis (RA). A 76-year-old woman visited our clinic for the first time in January 2017 because of ulceration and contact pain in the bilateral buccal mucosa and lingual margin, which had developed while receiving MTX therapy for RA. The patient had difficulty in dietary intake caused by intraoral pain associated with stomatitis and was thus hospitalized to undergo pain control and nutritional care. A diagnosis of MTX poisoning was made based on evidence showing an association with pancytopenia. After the withdrawal of MTX and administration of active folate, pancytopenia and stomatitis improved. Pancytopenia is an adverse side effect of MTX that is often fatal, while stomatitis is considered a prodromal symptom of pancytopenia. Stomatitis caused by MTX can be detected early by an examination performed by a dental or oral surgeon. Accordingly, to avoid an increase in severity in an affected patient, coordination with the attending physician in charge of their RA therapy is important.