A Case of Balsalazide-Induced Limited Form of Granulomatosis with Polyangiitis with Bronchiolitis Obliterans Organizing Pneumonia-like Variant in Ulcerative Colitis.

5-Aminosalicylate agents are the main therapeutic agents for ulcerative colitis. Balsalazide is a prodrug of 5-aminosalicylate and has fewer side effects than the other 5-aminosalicylate agents. Pulmonary complications resembling granulomatosis with polyangiitis in ulcerative colitis are extremely rare. Here, we report a patient with ulcerative colitis on balsalazide presenting respiratory symptoms and multiple pulmonary nodules from a chest radiography that was pathologically diagnosed with a limited form of granulomatosis with polyangiitis with bronchiolitis obliterans organizing pneumonia-like variant. To our knowledge, this is the first report of a balsalazide-induced limited form of granulomatosis with polyangiitis with bronchiolitis obliterans organizing pneumonia-like variant.