Editor's Note: It’s important to note that findings of comorbidity studies like this one only suggest a potential association. To determine any cause and effect relationship, further study is required.

A recent nationwide study in Taiwan has found an increased risk of inflammatory bowel disease (IBD) in people with rosacea, and of these, IBD was significantly more likely to occur in males.

In the new study, Dr. Chun-Ying Wu and colleagues examined the diagnoses of IBD, including Crohn’s disease or ulcerative colitis, in 89,356 subjects with rosacea and twice that many control subjects without the disorder from Taiwan’s national insurance database.  

The researchers found that individuals with rosacea were 1.94 times more likely to have IBD than those without. Male rosacea patients were 3.52 times more likely to have IBD than the control group.  The risk was less, however, in rosacea patients who took longer courses of antibiotics, the researchers said, although this finding did not reach statistical significance.

Inflammatory bowel disease occurs in parts of the gut containing the highest bacterial concentrations, they noted, and the composition of intestinal flora was observed to be altered in patients with IBD compared to healthy control subjects. However, no specific microorganism has been directly identified in the pathogenesis of IBD, and clinical trials have produced controversial results. 

Though there were no statistically significant differences in the incidence rates between various antibiotic treatment groups among the patients with rosacea in the study, there may still be a protective effect between long-term use of antibiotics and IBD development, the researchers said. 

Results in an earlier study appeared to indicate that change in intestinal bacteria may potentially be responsible for activity related to inflammation in rosacea, and they said if so this might explain in part the effectiveness of antibiotics in treating rosacea. They noted that broad-spectrum antibiotics have been reported to be associated with altered intestinal microorganisms.

Reference:

Wu CY, Chang YT, Juan CK, et al. Risk of inflammatory bowel disease in patients with rosacea: Results from a nationwide cohort study in Taiwan. J Am Acad Dermatol 2017 May;76(5):911-917.