Rosacea and gastrointestinal disorders: a population-based cohort study.

BACKGROUND Rosacea is a common inflammatory facial skin condition. Recent genetic and epidemiological studies have suggested pathogenic links between rosacea and gastrointestinal disorders, but data are limited. OBJECTIVES The objective was to investigate the association between rosacea and coeliac disease (CeD), Crohn disease (CD), ulcerative colitis (UC), Helicobacter pylori infection (HPI), small intestinal bacterial overgrowth (SIBO) and irritable bowel syndrome (IBS), respectively. METHODS We performed a nationwide cohort study. A total of 49 475 patients with rosacea and 4 312 213 general population controls were identified using nationwide administrative registers. We established the prevalence of the aforementioned disorders, and used Cox regression analysis to obtain hazard ratios (HRs) of the risk of new-onset CeD, CD, UC, HPI, SIBO and IBS, respectively, in patients with rosacea. RESULTS The prevalence of CeD, CD, UC, HPI, SIBO and IBS, respectively, was higher among patients with rosacea when compared with the control subjects. Adjusted HRs revealed significant associations between rosacea and CeD (HR 1·46, 1·11-1·93), CD (HR 1·45, 1·19-1·77), UC (HR 1·19, 1·02-1·39), and IBS (HR 1·34, 1·19-1·50), respectively, but not HPI (HR 1·04, 0·96-1·13) or SIBO (HR 0·71, 0·18-1·86). CONCLUSIONS Rosacea is associated with certain gastrointestinal diseases, but the possible pathogenic link is unknown. Gastrointestinal complaints in patients with rosacea should warrant clinical suspicion of disease.