Inflammatory bowel disease associated with chronic inflammatory skin diseases

A new study revealed that inflammatory bowel disease was associated with various chronic inflammatory skin diseases. IBD incidence was increased in patients with hidradenitis suppurativa, and CD was increased in patients with psoriasis. The study results were published in the journal British Journal of Dermatology.  

Several studies done in the past have linked various chronic inflammatory skin diseases (CISDs) with inflammatory bowel disease (IBD). But there are mixed conclusions hence researchers conducted a study to compare the incidence of IBD – ulcerative colitis (UC) and Crohn's disease (CD) – in patients with a CISD vs. similar persons without a CISD. 

Using nationwide, longitudinal, commercial insurance claims data from the USA, a cohort study was done on adults and children between 2004 and 2020 diagnosed with either psoriasis, atopic dermatitis, alopecia areata, vitiligo, or hidradenitis suppurativa. Comparator patients were identified through risk-set sampling. They were considered eligible if they were seen by a dermatologist at least twice and not diagnosed with a CISD. Patient follow-up was done until either IBD diagnosis, death, disenrollment, or end of the data stream, whichever came first. IBD events, UC or CD, were identified via validated algorithms using hospitalization or diagnosis with endoscopic confirmation. Incidence rates were computed before and after adjustment via propensity-score decile stratification to account for IBD risk factors. Hazard ratios (HR) and 95% confidence intervals (CIs) were estimated to compare the incidence of IBD in CISD vs. non-CISD.