[Acute alveolitis due to mesalazine]

A 66-year-old male developed lymphocytic alveolitis with bronchiolitis after 3 month's treatment with mesalazin for ulcerative colitis. The patient's symptoms disappeared after halting mesalazin and increasing the steroid dose, the reduced diffusing capacity ameliorated and the thoracic X-ray normalized. The question whether this was a case of pulmonary involvement in inflammatory bowel disease or a drug side effect.