Air Pollution and Health Care Use for Atopic Dermatitis: A Systematic Review.

Increasing air pollution is common around the world, but the impacts of outdoor air pollution exposure on atopic dermatitis (AD) are unclear. We synthesized the current global epidemiologic evidence for air pollution exposure and associated medical visits for AD among adults and children. This review followed PRISMA guidelines, and searches were conducted on PubMed, MEDLINE, Web of Science, and EMBASE databases. The searches yielded 390 studies, and after screening, 18 studies around the world with at least 5,197,643 medical visits for AD were included for the final analysis. We found that exposure to particulate matter less than 2.5 microns in diameter (PM 2.5 ) [(10/11) of studies], particulate matter less than 10 microns in diameter (PM 10 ) (11/13), nitrogen dioxide (NO 2 ) (12/14), and sulfur dioxide (SO 2 ) (10/13) was positively associated with AD visits. Results were equivocal for ozone [(4/8) of studies reported positive association] and limited for carbon monoxide [(1/4) of studies reported positive association]. When stratifying results by patient age, patient sex, and season, we found that the associations with particulate matter, NO 2 , and O 3 may be affected by temperature. Exposure to selected air pollutants is associated with AD visits, and increasingly poor air quality may increase global health care use for AD.