Risks of Inflammatory Bowel Disease in Individuals with Alopecia Areata: A Case-Control Study

Alopecia areata (AA) is a common autoimmune condition, affecting both physical and psychological well-being. IBD, encompassing ulcerative colitis and Crohn's disease, is marked by chronic intestinal inflammation. Since AA is associated with numerous autoimmune diseases, a potential link between AA and inflammatory bowel disease (IBD) has been suggested, though evidence remains limited. This study aimed to investigate the association between AA and IBD using data from a nationwide retrospective cohort. This large population-based case-control study analyzed data from Maccabi Healthcare Services (MHS), between 2005 and 2019. AA patients were matched to healthy controls in a 1:2 ratio by age and sex. The study included 100,203 individuals (33,401 AA cases and 66,802 controls). IBD was observed in 1.03 % of AA patients compared to 0.66 % of controls, demonstrating a significant association (OR = 1.55, 95% CI [1.35-1.79]). This association persisted across all age subgroups.