Churg–strauss syndrome: importance of colonoscopy and endoscopic biopsy in establishing diagnosis

A 31‐year‐old Japanese man was admitted with complaints of left lower abdominal pain and diarrhea. He had a history of bronchial asthma since he was 26 years old. On admission, his eosinophil count was 4100/mm ³ and increased as high as 12 000/mm ³ . A neurological examination disclosed mononeuritis multiplex with paresthesia in both lower and upper extremities. Because of hematochezia, colonoscopy was performed and disclosed multiple colonic ulcers and erosions from the rectum to the ascending colon. Endoscopic biopsy showed fibrinoid necrosis of small‐sized vessels with moderate infiltration of eosinophils in the mucosa and submucosa. He was suspected of being a case with Churg–Strauss syndrome (CSS; allergic granulomatous angiitis), and prednisolone of 30 mg/day was administered. After the administration of prednisolone, his eosinophil count decreased dramatically. His symptoms also improved gradually, except for numbness in the extremities. Three weeks later, colonoscopy revealed improvement of the mucosal appearance, but the colonic ulcers and erosions were still present. Endoscopic biopsy showed exravascular granuloma with moderate infiltration of eosinophils in the submucosa. Colonoscopy and endoscopic biopsy may be important in establishing the diagnosis of CSS with intestinal symptoms.