Acne therapy with isotretinoin is well tolerated in patients with established inflammatory bowel disease: a retrospective, single center study.

BACKGROUND

Early case reports and observational studies have suggested an association between isotretinoin and inflammatory bowel disease (IBD). However, large cohort studies and meta-analyses have not demonstrated a meaningful association between isotretinoin use and IBD development. Most prior research has focused on incident IBD risk, with limited attention to disease activity among patients with established IBD.

METHODS

We conducted a single-center retrospective cohort study of patients with Crohn's disease (CD) or ulcerative colitis (UC) treated with isotretinoin between 2015 and 2025. Inclusion required at least 1 IBD assessment within the 4 months before and 12 months after isotretinoin initiation. Disease activity was assessed using Harvey-Bradshaw Index (HBI), partial Mayo score (pMS), inflammatory biomarkers, and in some patients, intestinal ultrasound and fecal calprotectin. The primary outcome was composite IBD status change, defined as new clinical activity (Δ ≥ 1 in HBI/pMS), or isotretinoin discontinuation attributed to IBD activity.

RESULTS

Thirty-seven patients met inclusion criteria (57% CD, 43% UC). Most patients were in clinical remission at baseline (86%). Following isotretinoin exposure, 92% remained in remission, with no significant changes in HBI, pMS, erythrocyte sedimentation rate, C-reactive protein, or fecal calprotectin. IBD status change occurred in 4 patients (11%), with events largely attributable to underlying IBD-related factors, including biologic transitions, anti-drug antibody development, or medication dose adjustments.

CONCLUSIONS

Among patients with established, well-controlled IBD, isotretinoin was not associated with clinically meaningful worsening of disease activity, supporting its use in carefully selected patients with stable disease.