Distinct phenotypes of children with perianal perforating Crohn's disease

Purpose Perianal perforating disease (PF) has been reported in approximately 15% of children with Crohn's disease (CD). It is unknown whether children who present with PF at the time of diagnosis have a different course than those that develop PF while on therapy. Methods From a prospective, single institution observational registry of children diagnosed with CD, we identified children with perianal perforating CD, defined as perianal abscesses and/or fistulae. Patients who presented with perianal perforating CD (PF-CD ₀) were compared to those who developed perianal perforating CD (PF-CD₁) after initial diagnosis. Results Thirty-eight of 215 (18%) children with CD had PF-CD during a median follow up of 4.5 years. Patients with PF-CD₀ (n = 26) tended to be more likely male (81% vs. 50%, p = 0.07) and younger (9.3 yrs vs. 12.5 yrs, p = 0.02). PF-CD₁ (n = 12) patients were more likely to require diverting ileostomy (42% vs. 8%, p = 0.02) and colectomy (33% vs. 4%, p = 0.03). Multivariable analysis predicted increased rate of diverting ileostomy in the PF-CD₁ group (p = 0.007, OR 19.1, 95% CI 1.6-234.8). Conclusion Pediatric CD patients who develop PF while on therapy for CD have a more severe phenotype and are more likely to require diverting ileostomy or colectomy compared to those who present with PF-CD.