[A case of granulomatosis with polyangiitis with Crohn's disease-like findings].

A 22-year-old woman who was diagnosed with Crohn's disease experienced diarrhea and bloody stool. She was suspected of have aggravated Crohn's disease and was transferred to our hospital. Upper gastrointestinal endoscopy revealed multiple esophageal ulcers and erosive gastritis, while colonoscopy revealed multiple ulcers in the rectum to the sigmoid colon. Initially, the evidence suggested that the Crohn's disease had worsened, and consequently, prednisolone (PSL) therapy was initiated. However, the patient's condition was determined to be atypical inflammatory bowel disease, which was indicated by endoscopic findings and skin symptoms and because various test results did not meet the diagnostic criteria for Crohn's disease. As a result, her diagnosis was changed to granulomatosis with polyangiitis. Here, we report a case of granulomatosis with polyangiitis with gastrointestinal symptoms similar to Crohn's disease, both of which have been suggested to involve Th1/Th17 cells.