Extraintestinal manifestations of pediatric inflammatory bowel disease: prevalence, presentation and anti-TNF treatment

BACKGROUND There is a paucity of data on extraintestinal manifestations (EIM) and their treatment in pediatric patients with inflammatory bowel disease (IBD). METHODS Since 2008, the Pediatric Swiss IBD Cohort Study has collected data on the pediatric IBD population in Switzerland. Data on 329 patients were analyzed retrospectively. RESULTS 55 patients (16.7%) suffered from 1-4 EIM (39 Crohn's disease, 12 ulcerative colitis and 4 IBD-Unclassified (IBD-U) patients). At IBD onset, presence of EIM was more frequent than in the adult population (8.5% vs. 5.0%, p = 0.014). EIM were more frequent in CD when compared to UC/IBD-U (22.5 vs. 10.3%, p = 0.003). The most prevalent EIM were peripheral arthritis (26/329, 7.9%) and aphthous stomatitis (24/329, 7.3%). 27.6% of all EIM appeared before IBD diagnosis. Median time between IBD diagnosis and occurrence of first EIM was 1 month (-37.5-149.0). 31 of the 55 patients (56.4%) were treated with one or more anti-TNF agents. IBD patients with EIM were more likely to be treated with anti-TNF compared to those without (56.4% vs. 35.0%, p = 0.003). Response rates to anti-TNF depended on underlying EIM and were best for peripheral arthritis (61.5%) and uveitis (66.7%). CONCLUSIONS In a cohort of pediatric IBD patients, EIM were frequently encountered. In up to 30%, EIM appeared before IBD diagnosis. Knowledge of these findings might translate into an increased awareness of underlying IBD, thereby decreasing diagnostic delay. Anti- TNF for the treatment of certain EIM is effective although a substantial proportion of new EIM might present despite ongoing anti-TNF therapy.