Risk of new onset inflammatory bowel disease among acne vulgaris patients exposed to isotretinoin.

Abstract Background Data on risk of inflammatory bowel disease (IBD) among isotretinoin exposed acne vulgaris (AV) patients is controversial. Objective To compare IBD risk in isotretinoin exposed and unexposed AV patients. Methods Retrospective cohort analysis of AV patients with and without isotretinoin exposure identified using electronic health records. Primary outcomes were 6-months and 1-year IBD incidence. Results Crude 6-month IBD incidence was 0.08% (21/27,230) among isotretinoin exposed AV patients compared to 0.04% (254/631,089) among those unexposed. Crude 1-year IBD incidence was 0.10% (28/27,230) among isotretinoin exposed AV patients and 0.08% (477/631,089) among those unexposed. Odds of developing IBD within 6 months were 87% higher among isotretinoin exposed AV patients compared to those unexposed (aOR, 1.87; 95% CI, 1.20-2.93), though the absolute difference was small (risk difference, 2.6 more cases per 10,000 patients; 95% CI, 0.7-4.5 more cases per 10,000 patients). There was no significant difference in odds of developing IBD at 1-year between isotretinoin exposed and unexposed AV patients (aOR 1.40; 95% CI, 0.95-2.05). Limitations Isotretinoin exposed patients may be more likely to have IBD detected by a healthcare provider. Conclusion IBD incidence among isotretinoin exposed AV patients is very low and the risk appears similar to unexposed patients with AV.