Characteristics and long-term outcomes of children with perianal Crohn's disease.

Background/aims: The incidence of perianal lesions (PL) in children with Crohn's disease (CD) is higher in East Asia than in Western countries. Early intervention for PL is essential to prevent sphincter dysfunction and ostomy placement. In this study, we aimed to investigate the clinical features, treatment, and consequences of pediatric CD with PL.

Methods: We retrospectively reviewed a cohort of children diagnosed with CD from 2010 to 2020 at a Japanese children's hospital. Demographics, treatments, and outcomes were evaluated and compared among subgroups.

Results: Among 112 pediatric patients with CD, 36 (32.1%) had experienced PL during the observational period. The median ages at diagnosis and follow-up periods were 131 and 70 months, respectively. Six (85.7%) patients in the very early-onset (VEO) group (CD diagnosed before 6 years old) and 24 (82.8%) in the older age group had PL upon diagnosis of CD (P= 0.851). Biologics were given to 94.4% of patients: infliximab (67.7%), adalimumab (58.8%), ustekinumab (44.1%), risankizumab (11.8%), and vedolizumab (5.9%). Biologics were introduced within 1 year in 89.5% and 40.0% of patients diagnosed in 2016-2020 and 2010-2016, respectively (P= 0.002). Seton was frequently used in the older age group (87.5 vs. 42.9%, P= 0.190). Ostomy was frequently required in the VEO group (42.9% vs. 0.0%, P= 0.006).

Conclusions: Patients with VEO-CD and PL had a notably high risk of ostomy placement. The earlier introduction of biologics and surgical interventions reduced corticosteroids use and ostomy placement in pediatric CD patients with PL.