Background and aims: Ulcerative proctitis (UP) is an uncommon presentation in pediatric patients with ulcerative colitis. We aimed to characterize the clinical features and natural history of UP in children, and to identify predictors of poor outcomes.
Methods:The retrospective cohort study involved 37 sites affiliated with the IBD Interest group of ESPGHAN. Data were collected at different time points from patients aged<18 years diagnosed with UP between 01/01/2016-31/12/2020.
Results:We identified 250 patients with UP with a median follow-up of 2.7 (IQR 1.7-3.9) years. were included. Median age at diagnosis was 14.5 (IQR 12.3-15.9) years. Median follow-up was 2.7 (IQR 1.7-3.9) years. The most common presenting symptoms were bloody stools (93.6%), abdominal pain (60.4%) and diarrhea (52.8%). At diagnosis, the median pediatric ulcerative colitis activity index (PUCAI) score was 25 (IQR 20-35), the median fecal calprotectin level was 720 mcg/g (IQR 310-1800), notably 16 patients (11.7%) had a calprotectin level <100mcg/g. Most patients exhibited moderate-severe endoscopic inflammation. Oral, topical or By the end of induction, administration of orally, topically or combination of both resulted in clinical remission rates of 51.8%, 50.0% 73.3%, respectively at weeks 8-12?. The rates of treatment escalation to biologics at 1, 3 and 5 years were 10.6%, 22.7% and 44.6%. in multivariate analysis, Tthe PUCAI score at diagnosis was highly associated with escalation of therapy and subsequent events with acute severe colitis eventsand or IBD-associated admissions (multivariate analysis). By the end of follow-up, 3.4% of patients underwent colectomy. Cecal patch (P=0.009), higher PUCAI score (P=0.009) and lack of steroid-free clinical remission (P=0.005) by the end of induction were associated with proximal disease extension, identified in 48.3%..
Conclusion:Pediatric patients with UP exhibit high rates of proximal disease extension and treatment escalation.