Are Atopic Dermatitis and Inflammatory Bowel Diseases Associated?

While atopic dermatitis (AD) appears to have a causal effect on inflammatory bowel disease (IBD), the opposite was not found, researchers concluded in an observational study published in the Inflammatory Bowel Diseases.

“This study supports a causal effect between AD and IBD—but not between IBD and AD,” the report read. “There seems to be considerable differences between ulcerative colitis (UC) and Crohn disease (CD) regarding their specific associations with AD. These findings have implications for the management of IBD and AD in clinical practice.”

Through a 2-sample Mendelian randomization study, the researchers used independent genetic instruments to investigate the association between AD and IBD in the UK Biobank sample (7045 cases, 456,327 controls) and a European IBD sample (12,882 cases, 21,770 controls).

In the UK Biobank study, AD was strongly associated with higher risk of IBD (odds ratio [OR], 1.107; 95% confidence interval [CI], 1.035; 1.183), as well as in the European IBD study (OR, 1.114; 95% CI, 0.956; 1.298). Combining the results from both the studies, the meta-analyses confirmed a strong association in totality (OR, 1.11; 95% CI, 1.04; 1.18).

When evaluating the association of IBD on AD, analyses revealed a strong association with UC (OR, 1.149; 95% CI, 1.018; 1.297) and a suggestive association with CD (OR, 1.034; 95% CI, 1.004; 1.064) The results supported the causal effect between AD and IBD—but not between IBD and AD.

—Priyam Vora

Reference:
Meisinger C and Freuer D. Causal association between atopic dermatitis and inflammatory bowel disease: A 2-sample bidirectional mendelian randomization study. Inflamm Bow Dis. 2022: 28(10); 1543–1548. DOI: https://doi.org/10.1093/ibd/izab329