Perianal Disease Modifiers Are Associated With Less Severe Luminal Disease Activity in Children With Crohn's Disease at Diagnosis

Abstract

Background: There is lack of data regarding the associations between perianal fistulizing disease and other disease characteristics at diagnosis in children with Crohn&apos;s disease (CD). We sought to investigate the associations between perianal fistulizing disease and other disease characteristics at diagnosis in children with CD. Methods: This was a multicenter, registry-based, inception cohort study conducted in Korea. Children newly diagnosed with CD were included. Baseline clinicodemographics; results from laboratory, endoscopic, histologic exams; and Paris classification factors were collected, and associations between factors were investigated. Results: A total 699 patients were included. The median age at diagnosis was 14.3 years (IQR, 12.3-15.9 years), and the male-to-female ratio was 2.66:1. Perianal disease modifiers comprised 50.6% (n = 354 of 699) of the patients. The proportion of perianal disease modifiers was higher in males (81.1% vs 64.1%; P < .001), in those with upper gastrointestinal tract involvement (85.3% vs 75.7%; P = .002), and in those with B1 behavior (89.5% vs 79.7%; P < .001). Albumin was higher (P = .006) and CRP was lower (P < .001) in patients with perianal disease modifiers. Females had a higher proportion of B2/B3 behavior (21.4% vs 14.4%; P = .029), higher Pediatric Crohn&apos;s Disease Activity Index scores (median 40 vs 32.5; P < .001), higher CRP (P = .017), higher Simple Endoscopic Score for Crohn&apos;s Disease scores (P = .01), and more frequent detection of noncaseating granulomas in the lower gastrointestinal tract (P = .008). Conclusions: Perianal fistulizing disease was more common in boys who exhibited milder disease activity, indicating the importance of recognizing perianal fistulizing disease as a clinical clue to the early diagnosis of underlying luminal CD.