Prevalence and outcomes of arthritis in pediatric IBD: A multicenter study from the Italian Society of Pediatric Gastroenterology Hepatology and Nutrition.

Background And Aims: The aim of the present study was to assess prevalence and disease outcomes of arthritis in a nationwide cohort of pediatric patients with inflammatory bowel disease (IBD).

Methods: We collected data of pediatric IBD patients experiencing arthritis from the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition IBD registry. We gathered baseline and one-year follow-up data on concomitant IBD and arthritis diagnosis.

Results: 150 patients [(99 Crohn's Disease (CD), 51 Ulcerative Colitis (UC) and Unclassified IBD (IBDU)] with arthritis out of 3061 (1301 CD and 1760 UC) patients were identified, with an overall prevalence of 4.9 %. Arthritis was more frequent in CD than in UC (7.6 % vs 2.9 %, p < 0.01). Peripheral arthritis was more frequently diagnosed in patients with active IBD than in those with quiescent disease (94.6 % vs 67.3 %, p < 0.01). At one-year follow-up, clinically active IBD was independently associated with lower peripheral arthritis remission rates, whereas it did not impact axial arthritis remission. The presence of additional EIMs was associated with lower IBD clinical remission rates.

Discussion: Clinically active IBD impacts peripheral arthritis but not axial one, whose activity appeared to be independent by intestinal disease. The presence of additional EIMs has a negative prognostic impact on IBD course.