Inflammatory bowel disease is associated with an increased risk of inflammatory skin diseases: A population-based cross-sectional study

Background Inflammatory bowel disease (IBD) is a chronic disease of the gastrointestinal tract attributed to aberrant activity of the immune system. Increasing evidence suggests that patients with IBD are at an increased risk of inflammatory skin diseases (ISDs). Objective We sought to clarify the association between IBD and ISDs using a nationwide health claims database maintained in Korea. Methods We interrogated Korean health claim database data from 2009 to 2013. We enrolled all patients with IBD, and age- and sex-matched control subjects, and evaluated the risks of ISDs, including psoriasis, rosacea, and atopic dermatitis, and the risks of autoimmune skin diseases, including vitiligo and alopecia areata. We used multivariable logistic regression to this end. Results ISDs including rosacea, psoriasis, and atopic dermatitis were significantly associated with IBD, whereas the associations between IBD and autoimmune skin diseases including vitiligo and alopecia areata were less marked or nonexistent. Ulcerative colitis and Crohn's disease were both associated with ISDs. Limitations We were unable to distinguish phenotypes and severities of skin diseases. Conclusion IBD was significantly associated with ISDs, but less so or not at all with autoimmune skin diseases.