Title: Low dose methotrexate pneumonitis in rheumatoid arthritis.
Abstract: The antimetabolite drug methotrexate has recently been used in the treatment of rheumatoid arthritis refractory to conventional antirheumatic drugs.1-3 The doses of methotrexate used in such cases are much lower than those used in the treatment of malignancy or skin disorders. Instances of diffuse interstitial pneumonitis apparently related to the use of methotrexate in such low doses are uncommon.45 We report a case in which diffuse pneumonitis developed after low weekly and low accumulative doses of methorexate and which showed spontaneous resolution after the drug had been discontinued.