[Pneumonitis caused by mesalazine].

5-aminosalicylic acid (5-ASA) has been used to treat inflammatory bowel disease satisfactorily. Lung disease related to 5-ASA administration has been described only rarely. We report a case of alveolitis related to 5-ASA treatment in a woman with Crohn's disease. We review the literature and describe clinical, biological and radiological manifestations, along with the clinical course of this complication.