Perianal Crohn Disease Is More Common in Children and Is Associated With Complicated Disease Course Despite Higher Utilization of Biologics

ABSTRACT Background and Objectives: Both perianal and pediatric‐onset Crohn disease (CD) disease are associated with complicated disease course and higher drug utilization. we aimed to explore the differences between pediatric and adult‐onset perianal CD and their disease course. Methods: We included all patients with newly diagnosed CD from 2005 to 2019 at two Israeli Health Maintenance Organizations, covering 78% of the population. A combination of ICD‐9 codes, radiology and procedures was used to define fistulizing perianal CD (PCD) and its severity according to the association with simple and complex perianal disease. Results: A total of 12,905 patients were included (2186 [17%] pediatric‐onset, 10,719 [83%] adults), with a median follow‐up of 7.8 years. PCD was diagnosed in 1530 (12%) patients, with higher incidence in children (308 [14%] children vs 1222 adults [11%]; P < 0.001). Children had higher incidence of severe PCD (141/308 [47%] vs 433/1222 [35%]; P < 0.001). At 5 years, children with PCD were more likely than adults to be treated with biologics (212 [69%] vs 515 [42%]; odds ratio [OR] 2.6 [95% confidence interval (CI) 1.6–4.0]; P < 0.001) and immunomodulators (238 [74%] vs 643 [53%]; OR 2.8 [95% CI 2.1–3.6]; P < 0.001). PCD in children was still associated with poorer disease outcomes as shown for surgeries (36 [12%] vs 93 [8%]; P = 0.02) and steroid‐dependency (52 [17%] vs 156 [13%]; P < 0.001). Multivariable modeling indicated that the severity of PCD is a stronger predictor of disease course than age. Conclusion: PCD is more common in pediatric‐onset CD and is associated with higher drug utilization and worse disease outcomes, in large due to higher rate of severe PCD in children.