Differential diagnosis in ulcerative colitis in an adolescent: Chronic granulomatous disease needs extra attention

Chronic granulomatous disease(CGD) is a primary immune deficiency that is commonly diagnosed under the age of 5 years(95%) and is rarely seen in adulthood. CGD may manifest as inflammatory bowel disease(IBD) in childhood. Without proper diagnosis, these patients may be monitored for years as IBD; some may even be regarded as steroid-resistant ulcerative colitis(UC) and end up having a colectomy. In this case report, we described a patient who had been followedup for years as UC and subsequently underwent colectomy, but was finally diagnosed in adulthood as primary immune deficiency.