Pulmonary function changes in patients with psoriasis on methotrexate therapy.

Methotrexate is known to induce pulmonary fibrosis. The present study was undertaken to assess pulmonary toxicity, if any, in psoriasis patients on methotrexate therapy and correlate the dose and duration of the treatment with any changes in pulmonary function. Ten patients who had taken methotrexate for one year and ten patients receiving methotrexate were included in the present study. Detailed lung function studies including arterial blood gas analysis were carried out. In both groups, the only pulmonary function abnormalities detected were FEF200-1200, FEF25-75%, residual volume (RV), and RV/TLC%, which showed a decline after six months of treatment. However, this was not significant. No changes were detected in the arterial blood gas values following methotrexate therapy. Therefore, the present study did not find any significant deterioration of lung functions in psoriasis patients on methotrexate therapy.