Pulmonary abnormalities in inflammatory bowel disease.

Extraintestinal manifestations of inflammatory bowel disease (IBD) is a common clinical problem affecting up to half of all IBD patients; pulmonary disease, however, ranks among less common extraintestinal manifestations of IBD. Pulmonary disease in patients with IBD is most frequently drug induced due to treatment with sulfasalazine or mesalamine leading to eosinophilic pneumonia and fibrosing alveolitis or due to treatment with methotrexate leading to pneumonitis. Recently, various opportunistic infections have been shown to be a further important cause of pulmonary abnormalities in those IBD patients who are treated with immunosuppressants such as anti TNF-α monoclonal antibodies, methotrexate, azathioprine or calcineurin antagonists. In not drug related pulmonary disease a wide spectrum of disease entities ranging from small and large airway dysfunction to obstructive and interstitial lung disorders exist. Patients with lung disorders and inflammatory bowel disease should be evaluated for drug-induced lung disease and opportunistic infections prior to considering pulmonary disease as an extraintestinal manifestation of inflammatory bowel disease.