Low-dose methotrexate-induced acute interstitial pneumonitis: Report of two cases from South India and review of literature.

Methotrexate (MTX) is an antimetabolite used as a disease-modifying agent for various rheumatological conditions. We report two patients who were treated with daily low-dose MTX and developed acute interstitial pneumonitis requiring hospital admission. MTX-induced pneumonitis is a rare life-threatening side effect, high index of clinical suspicion is required, treatment is mainly withdrawal of MTX, supportive therapy, and adjunctive steroids, outcome is good if condition is recognized early, and appropriate treatment is given.