This systematic review and meta-analysis evaluated the incidence of IBD (new-onset or worsening Crohn disease or ulcerative colitis) in HS patients treated with IL-17 inhibitors, comparing event rates between treatment and placebo groups across 24 studies (10 RCTs, 11 nonrandomized studies, 3 case reports) identified through November 2025.
In 10 RCTs, new-onset IBD occurred in 6/2572 IL-17 inhibitor-treated patients (0.23%) vs. 0/1066 placebo patients through week 16 — no significant difference (risk difference 0.002; 95% CI, −0.003 to 0.007). Nonrandomized studies showed a pooled IBD incidence of 3.90% (95% CI, 2.30%–6.50%), though crude incidence was 1.49% (7/469 patients). Across all study types, 17 new-onset and 4 IBD flare events were reported.
- RCT follow-up was limited to 16 weeks, too short to capture delayed IBD onset. - Very low event rates reduced statistical power to detect a true difference. - Inconsistent IBD reporting across studies made pooled interpretation difficult.
IL-17 inhibitors do not appear to significantly raise IBD risk in HS patients over the short term, but clinicians should screen for IBD history before starting therapy and monitor for GI symptoms, given the baseline elevated IBD risk in HS populations and limited long-term data.
