WASHINGTON (FRONTLINE MEDICAL NEWS) Patients with hidradenitis suppurativa (HS) face an increased risk of also developing inflammatory bowel disease (IBD), Ahuva Cices said at the annual meeting of the American Academy of Dermatology.

In a case-control study, Ms. Cices found that those with a new diagnosis of HS were twice as likely as controls to also be diagnosed with inflammatory bowel disease, either concurrently or shortly afterward.

“Our findings support a comorbid relationship between these two disorders, and suggest that hidradenitis suppurativa should be considered a risk factor for IBD and impart increased clinical suspicion for undiagnosed IBD,” said Ms. Cices of Northwestern University, Chicago.

She and her coinvestigators at Northwestern searched a large academic medical center database for patients with a diagnosis of HS from 2005 to 2015. These 1,332 patients were matched with about 2,600 control subjects. Of the individuals with HS, 20 were also concurrently or subsequently diagnosed with IBD. The mean lag time to an IBD diagnosis was 9 months.

The mean age of the patients with both conditions was almost 40 years. Most (75%) were female – significantly more than in the control group (42%). About half of the patients (45%) were black – also significantly more than in the control group (10%).

In a multivariate analysis, a diagnosis of HS conferred a doubling in the risk of a concurrent or subsequent diagnosis of IBD (odds ratio, 2.11), which was statistically significant.

The pathophysiologic link between the two diseases has been theorized but not confirmed, Ms. Cices said.

“The multifactorial pathways of HS and IBD are complicated, but they both involve inflammatory responses to normal flora, immune dysfunction, and dysregulation of Notch, the sulfotransferase enzyme, [tumor necrosis factor–]alpha, and T-helper 17 cells.”

She had no relevant financial disclosures.