Pneumonitis due to cytomegalovirus during chronic methotrexate treatment.

Although hypersensitivity pneumonitis is the most common pulmonary complication described during treatment with methotrexate, other complications like lymphoproliferative and infectious disease may be considered in the study of respiratory disease associated to methotrexate. The existence of an increased risk to developing infectious diseases may be similar to that observed during treatment with antagonists of tumor necrosis factor and corticosteroids, where Cytomegalovirus pneumonia is a serious complication; early diagnosis and treatment will prevent a potentially fatal outcome.