Association between atopic dermatitis and extracutaneous bacterial and mycobacterial infections: A systematic review and meta-analysis

Background: Atopic dermatitis (AD) is associated with increased bacterial colonization and infection of skin and multiple risk factors for extracutaneous infections. However, previous studies found conflicting results about whether AD is associated with increased extracutaneous infections. Objective: To determine whether extracutaneous bacterial and mycobacterial infections are increased in AD. Methods: A systematic review was performed of all published observational studies with controls in MEDLINE, EMBASE, Global Resource of EczemA Trials, Cochrane, and Web of Science that assessed extracutaneous infections in AD. Pooled meta-analysis was performed by using random-effects weighting. Results: Overall, 7 studies met inclusion criteria. All 7 studies found an increased odds for at least 1 extracutaneous infection, including endocarditis, meningitis, encephalitis, bone and joint infections, and sepsis, in AD patients. In pooled meta-analysis, AD in children and adults was associated with a higher odds of ear infection (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.16-1.43), strep throat (OR 2.31, 95% CI 1.66-3.22), and urinary tract infection (OR 2.31, 95% CI 1.66-3.22) but not pneumonia (OR 1.72, 95% CI 0.75-3.98). No publication bias was detected. Limitations: Individual-level data were not available. Conclusion: AD patients have higher odds of extracutaneous infections. Future studies are needed to confirm these associations and determine their mechanisms.