Introduction

Inflammatory bowel disease (IBD) is a chronic relapsing and remitting disease that is increasing in incidence throughout the Western world.1 Although multiple questions regarding its aetiology remain, immunosuppressive therapy is used as the mainstream treatment in both adults and children.2 Concerns have been raised regarding theirsafety and potential side effects on a short-term and long-term basis. Several databases have been initiated to evaluate this effect. Based on recent reports of an increased incidence of hepatosplenic T cell lymphoma in young male IBD patients receiving a combination therapy of anti-tumour necrosis factor antibodies and azathioprine (Aza), malignancy is the most dreaded complication.3 Nevertheless, as in all immunosuppressed patients, opportunistic infections are an important caveat.4 Here, we would like to focus on the risk for opportunistic infections due to immunosuppression in paediatric IBD and various aspects of prevention. Unfortunately, because paediatric data on this topic are scarce, data from adult IBD and rheumatoid arthritis populations are included.