Interleukin‐10 receptor mutation presenting with severe nappy ulceration and infantile inflammatory bowel disease

Summary Inflammatory bowel disease ( IBD ) can be divided into Crohn disease, ulcerative colitis and inflammatory bowel disease unclassified ( IBDU ). In most patients, these disorders present in adolescence or early adulthood. Patients with infantile IBD can have an associated underlying immunodeficiency disorder caused by a mutation in interleukin ( IL )‐10 or its receptor. We describe a child presenting with intractable bloody diarrhoea since 2 weeks of age and with severe nappy ulceration, who was ultimately diagnosed as having inflammatory bowel disease ( IBD ) due to an immunodeficiency in the IL ‐10 receptor. This report highlights the importance of considering this rare immunodeficiency in patients with infantile IBD presenting with severe perianal disease to a dermatologist.