Annika Ström[1,2], Sabine Jansson[1,2], Mads Damsgaard Wewer[2,3], Johan Burisch [2,3,4], Mikkel Malham[1,2,5,6], Vibeke Wewer[1,2,4]

Affiliates

Department of Paediatric and Adolescent Medicine, Copenhagen University Hospital, Amager and Hvidovre Hospital, Hvidovre, Denmark[1], Copenhagen Center for Inflammatory Bowel Disease in Children, Adolescents, and Adults, Amager and Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark [2], Gastrounit, Medical Division, Copenhagen University Hospital, Amager and Hvidovre, Hvidovre, Denmark[3], Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark[4], Department of Paediatric Gastroenterology and Nutrition, Royal Hospital for Children and Young People, Edinburgh, United Kingdom[5], Copenhagen Health Complexity Center, Department of Public Health, University of Copenhagen, Copenhagen, Denmark[6]

Abstract

Background: Perianal Crohn’s disease (CD) occurs in both adult and paediatric patients and is characterised by inflammation at the anal region and can present with skin tags, fissures, fistulae, abscesses, and stenosis of varying complexity. We aimed to estimate the occurrence and describe the disease course of perianal disease in patients with paediatric-onset CD.
Methods: In a nationwide population-based cohort study, we investigated the incidence of perianal disease in paediatric-onset CD patients, and risk of abdominal surgery, colorectal and anal cancer, and mortality in patients with and without perianal disease by using data from national health registers in Denmark. This study included all incident paediatric-onset CD patients (<18 years at CD diagnosis) in Denmark from 1980 to 2018. Follow-up continued until emigration, death, or December 31, 2022. We used multivariate Cox regression analysis with biological age as the timescale to estimate hazard ratios (HR). The risk estimates were further adjusted (aHR) for sex and calendar year of CD diagnosis.
Results: We included 2,356 patients with paediatric-onset CD. During follow-up, 769 (33%) patients were diagnosed with perianal CD, of whom 427 (55.5%) were males. Median age at perianal diagnosis was 17.6 years (interquartile range [IQR]: 14.6–22.9). The cumulative incidence of perianal CD was 14.0%, 21.1%, and 28.1% after 1, 5, and 10 years from CD diagnosis, respectively. Among the 769 patients with perianal CD, 460 (59.8%) had perianal abscesses, 399 (51.9%) perianal fistula, and 627 (81.5%) patients underwent perianal surgery. The risk of major abdominal surgery was significantly higher for patients with perianal CD (adjusted hazard ratio [aHR] 1.5, 95% confidence interval [CI]: 1.3–1.8) compared to those without perianal disease. We found no difference in bowel related cancer risk between patients developing perianal disease and those who did not (aHR 0.6 [95% CI: 0.2–2.1]). During follow-up, 68 (2.9%) patients died, 35 (51.5%) of whom had perianal disease corresponding to an aHR of 1.40 (95%CI: 0.8–2.3).
Conclusion: In this nationwide cohort of patients with paediatric-onset CD, 33% developed perianal disease. Patients with perianal CD had a 50% higher risk of major abdominal surgery compared to patients without perianal CD. We did not find a significant difference in the risk of cancer or mortality. For mortality, however, the result was not as clear.

Poster_P1 Annika Ström