It has been argued that the relationship between inflammatory bowel disease (IBD) and rosacea is bi-directional, but this hypothesis has not been explicitly tested. This systematic review examines the bi-directional prospective relationships between IBD and rosacea.
A comprehensive search through PubMed and EMBASE was undertaken for studies investigating the association between two mainly forms of IBD [ulcerative colitis (UC) and Crohn's disease (CD)] and rosacea published in English until Jan 2018. Reviewers assessed the eligibility of each report by exposure/outcome measurement and study design. Two sets of pooled risk estimates were calculated using fixed or random effects: the direction from IBD to rosacea and rosacea to IBD.
Five publications on 13 separate study results involving 5,051,356 participants were eligible for this meta-analysis. A total of 6 outcomes established the direction of association from IBD to rosacea, and 7 outcomes examined the direction of association from rosacea to IBD. Compared to a non-rosacea population, the pooled RR (95% CI) for overall IBD, UC and CD were 1.32 (1.18-1.49), 1.19 (1.02-1.38) and 1.52 (1.25-1.84), respectively (P < 0.05). Meanwhile, the summary RR (95% CI) of rosacea in overall IBD, UC and CD patients were 1.66 (1.50-1.84), 1.69 (1.48-1.93) and 2.08 (1.26-3.46), respectively (P < 0.05).
Our meta-analysis confirmed a significant bi-directional association in occurrence of IBD and rosacea. Future studies should specifically investigate possible shared pathophysiological mechanisms between the two disorders.