Association of atopic dermatitis with vitiligo: A systematic review and meta-analysis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with multiple immune-mediated disorders. A comprehensive meta-analysis assessing the prevalence or risk of vitiligo in AD patients is lacking. OBJECTIVE: To compare the prevalence and assess the risk of vitiligo in patients with AD by performing a meta-analysis of observational studies. METHODS: PubMed, Scopus, and Cochrane databases were systematically searched until August 25, 2019, following the PRISMA guidelines. Published English-language articles including case-control, cross-sectional, or cohort studies that reported either odds or risk of vitiligo in AD patients were included. Full-text review and study assessment were performed by the two authors independently. Random-effects meta-analysis model was used to calculate the odds ratio (OR) and risk ratio (RR) with the corresponding 95% confidence interval (CI). The risk of bias was assessed using the Newcastle-Ottawa Scale. RESULTS: Seven studies with a total of 1 540 688 unique AD patients were included. The random-effects meta-analysis of case-control and cross-sectional studies showed a significant association of AD with vitiligo (OR, 3.21; 95% CI, 1.90-5.43). Subgroup analyses also showed a significant association for both adult AD (OR, 4.46; 95% CI, 1.65-12.07) and childhood AD (OR, 2.83; 95% CI, 1.53-5.25). Pooling of the results of 2 cohort studies showed an increased risk of vitiligo in patients with AD (RR, 1.64; 95% CI, 1.27-2.13). CONCLUSIONS: Results from this study support an association of AD with vitiligo. Exploration of possible mechanisms responsible for this association could be important to develop proper treatment approaches for the affected patients.