A Case of Methotrexate: Associated Interstitial Pneumonitis in Rheumatoid Arthritis

Kim, Ji Yeon; Kim, Wan Uk; Kim, Sung Il; Yoo, Wan Hee; Park, Sung Hwan; Hong, Yeon Sik; Kim, Seok Chan; Cho, Chul Soo; Kim, Ho Youn; Lee, Youn Soo

Abstract

The use of oral methotrexate in a low dose given once weekly has become the mainstay of therapy for active and sustained rheumatoid arthritis. Pneumonitis can be expected to occur in patients taking low doses of methotrexate for rheumatoid arthritis. The pathology suggests that methotrexate pneumonitis is a hypersensitivity reaction although arguments have been put forth that it is idiosyncratic. Treatment of presumed methotrexate pneumonitis, even while waiting for special stains, cultures, or tissue sections from bronchoscopic biopsy, should be glucocorticoids given intravenously or by mouth. Empirical antibiotic treatment can be used until infectious causes are ruled out. In recent years there has been an increase in the number of reports of pulmonary complications associated with low-dose methotrexate therapy for rheumatic diseases. Among these complications interstitial pneumonitis has been most often reported (more than 35 cases since the first report in 1983). We report a case of methotrexateassociated pulmonary complication in rheumatoid arthritis confirmed by transbronchoscopic lung biopsy, which resolved by treatment of corticosteroid therapy.