The frequency and clinical characteristics of methotrexate (MTX) oral toxicity in rheumatoid arthritis (RA): a masked and controlled study.

To assess the frequency and clinical characteristics of methotrexate (MTX) oral toxicity in rheumatoid arthritis (RA) patients, 51 RA patients receiving MTX and 46 RA patients not receiving MTX were studied. A questionnaire, the credibility of which was tested on four separate patient groups including a group with Behcet's Syndrome, was used as a tool to determine the prevalence of stomatitis by a blind observer. In this first controlled study of the oral toxicity of MTX, prevalence of stomatitis was found in 37.2% in the group taking MTX and 19.5% in the group not taking MTX (P = 0.054). No statistical differences were detected with respect to number, duration, frequency, and site of stomatitis. Two of the 51 MTX taking patients temporarily reduced their MTX dosage and only one patient temporarily terminated MTX treatment. MTX and toxicity is usually of no major clinical concern in the treatment of RA.