Interstitial pneumonia due to sulfasalazine.

A 45-year old man with ulcerative colitis developed a dry cough, dyspnoea and pulmonary infiltrates after two months of sulfasalazine treatment. Transbronchial lung biopsy showed interstitial pneumonia. Withdrawal of the drug and institution of corticosteroids resulted in rapid recovery. After challenge with sulfasalazine, symptoms and signs of interstitial pneumonia reappeared.