Background: Chronic granulomatous disease is a rare inherited disorder of the innate immune system. In patients with a clinical history of recurrent or persistent infections, especially infections caused by uncommon species, chronic granulomatous disease should be considered.
Case presentation: We report the case of a 5-year-old boy with a presumptive diagnosis of Crohn's disease with extraintestinal manifestations. Chronic granulomatous disease was suspected in this case after Serratia marcescens was isolated from a skin ulcer culture. Granulomas were confirmed on histology and chronic granulomatous disease was diagnosed.
Conclusion: This case emphasizes the importance of high clinical suspicion of an alternative diagnosis of immune deficiency in patients with presumed inflammatory bowel disease and opportunistic infections, especially when disease occurs in early life.