Association between Isotretinoin Exposure and Inflammatory Bowel Disease: A Nationwide Case-Control Study in South Korea.

Context Isotretinoin is commonly prescribed for the treatment of acne. However, its association with inflammatory bowel disease (IBD) could not be confirmed due to inconsistencies in the literature. Furthermore, no related study has been conducted on an Asian population. Aims The aim of this study was to investigate the association between isotretinoin and inflammatory bowel disease. Methods and Material A nationwide, population-based, case-control study using the National Health Insurance Service database of South Korea was conducted. The case group comprised 107,434 patients with IBD, while the control group comprised 393,830 patients who were matched using a 1:4 propensity score. Data on isotretinoin exposure within the previous 5 years were extracted, and a multivariable-adjusted, conditional, logistic, regression analysis was performed. Results After adjusting for age, sex, underlying disease, the Charlson co-morbidity index, and tetracycline use, a significant association between isotretinoin exposure and IBD was found, with an odds ratio of 1.20 (95% confidence interval, 1.10-1.30). Furthermore, the association appeared to become stronger with longer exposure, more of a cumulative dose, and a longer time since the first exposure. When analyzed separately for ulcerative colitis and Crohn's disease, isotretinoin exposure was significantly associated with both diseases. Conclusions Our study reveals a dose-response relationship between isotretinoin exposure and IBD risk in an Asian population. Healthcare professionals should be aware of the association and consider alternative medications for acne treatment, particularly in patients who are at a higher risk of developing IBD.