RESUMO
Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease. Mesalizine for the first-line therapy of UC has adverse effects include pancreatitis, pneumonia and pericarditis. UC complicated by two coexisting conditions, however, is very rare. Moreover, drug-related pulmonary toxicity is particularly rare. An 11-year-old male patient was hospitalized for recurring upper abdominal pain after meals with vomiting, hematochezia and exertional dyspnea developing at 2 weeks of mesalizine therapy for UC. The serum level of lipase was elevated. Chest X-ray and thorax computed tomography showed interstitial pneumonitis. Mesalizine was discontinued and steroid therapy was initiated. Five days after admission, symptoms were resolved and mesalizine was resumed after a drop in amylase and lipase level. Symptoms returned the following day, however, accompanied by increased the serum levels of amylase and lipase. Mesalizine was discontinued again and recurring symptoms rapidly improved.