Inflammatory bowel disease (IBD) is associated with an increased risk of hidradenitis suppurativa (HS), according to a study presented at AIBD 2024.

“HS is a chronic inflammatory skin condition often associated with IBD, particularly Crohn’s disease (CD) and ulcerative colitis (UC),” said the researchers.

Using data from the TriNetX database between 2004 and 2024, the researchers conducted a retrospective study involving 205,386 patients diagnosed with IBD. [AIBD2024, abstract S21]

Among patients with IBD, 2.99 percent had HS, which occurred more frequently in males than in females (3.48 percent vs 2.78 percent).

Notably, a higher prevalence of HS was observed among patients with Crohn’s disease than those with UC (2.14 percent vs 1.38 percent), with an incidence rate of 5.71 cases per person-day.

In a propensity-matched analysis, IBD patients with HS had a significantly higher rate of bowel obstruction than IBD patients without HS (odds ratio [OR] 1.728, 95 percent confidence interval [CI], 1.630?1.833; p=0.01).

The rate of colectomy and risk of intestinal perforation did not differ significantly between patients with IBD who had HS and those who did not (OR, 1.07, 95 percent CI, 0.920?1.262; p=0.35 and OR, 1.09, 95 percent CI, 0.846?1.417; p=0.49, respectively).

“HS was associated with more severe disease activity in both CD and UC patients, with the association being stronger in CD patients,” said the researchers.

In a further analysis of IBD patients with HS, the mortality rates were higher in the UC than the CD cohort (OR, 1.406, 95 percent CI, 1.094?1.807; p=0.007), but the all-cause hospitalization rates did not differ between the two cohorts.

On the other hand, patients with CD and HS were more likely to experience complications, including colectomy (OR, 0.597; p=0.016), fistula (OR, 0.159; p=0.001), stricture/obstruction (OR, 0.393; p=0.001), abscess (OR, 0.266; p=0.001), and ulcers (OR 0.475), than those with UC and HS.

“Overall, this study highlights an increased prevalence of HS in patients with IBD, particularly in those with CD, and a higher risk of bowel obstruction in patients with both conditions,” the researchers concluded.

“HS may indicate a more severe disease activity in IBD, especially in CD, warranting further research to explore shared inflammatory mechanisms and optimize treatment,” they added.