Aim: To determine the incidence, presentation, and initial management of paediatric inflammatory bowel disease in New Zealand.
Methods: A prospective study in collaboration with the New Zealand Paediatric Surveillance Unit was undertaken between 2002-2003. Paediatricians and healthcare professionals working with children were surveyed monthly for cases of paediatric inflammatory bowel disease.
Results: There were 52 cases(30 males); 34 (66%) Crohn's disease, 9 (17%) ulcerative colitis, and 9 (17%) inflammatory bowel disease type unclassified. The estimated incidence of paediatric inflammatory bowel disease, Crohn's disease, and ulcerative colitis were 2.9, 1.9, and 0.5 per 100,000 per year respectively. Mean age at diagnosis was 11 years with a delay of 8.4 months from clinical presentation to diagnosis. 85% were European, while no Maori or Pacific Islanders had Crohn's disease or ulcerative colitis. The most common symptoms at presentation were abdominal pain (63%), rectal bleeding (57%), diarrhoea (55%), and weight loss (43%). 39% of Crohn's disease patients had perianal disease at presentation. Only 18% of the Crohn's disease patients presented with the classic triad of symptoms-abdominal pain, weight loss, and diarrhoea. Haematological laboratory abnormalities were more common in Crohn's disease. 5-aminosalicylic acid agents were the most common initial therapy followed by systemic steroids. 25% of the paediatric inflammatory bowel disease cohort received immunomodulators.
Conclusions: The incidence of paediatric inflammatory bowel disease in New Zealand is comparable but at the lower end relative to North America and United Kingdom. There is more Crohn's disease than ulcerative colitis and only a minority of Crohn's disease patients presented with the classic triad of abdominal pain, weight loss, and diarrhoea. 5-aminosalicylic acid preparations and steroids as first line treatment of Crohn's disease were much more common than nutritional therapy. It is rare for New Zealand Polynesian children to develop paediatric inflammatory bowel disease.