Low dose methotrexate therapy for rheumatoid arthritis complicated by pancytopenia and Pneumocystis carinii pneumonia.

Abstract

In a patient with rheumatoid arthritis pancytopenia and Pneumocystis carinii pneumonia occurred during low dose methotrexate therapy. This case emphasizes the potential development of opportunistic infections even with low dose methotrexate. Pneumocystis carinii pneumonia resembles methotrexate induced pneumonitis. Therefore opportunistic infections should be considered before a definite diagnosis of methotrexate induced pneumonitis is made.