Adult atopic dermatitis and exposure to air pollutants-a nationwide population-based study.

BACKGROUND: There is a trend toward an increased worldwide prevalence of allergic diseases. It is speculated that industrialization with resultant air pollution plays a role. However, there are sparse epidemiologic data on the relation between air pollution and atopic dermatitis (AD) in adults.

OBJECTIVE: To investigate the relation between exposure to air pollutants and adult AD in a cross-sectional study based on data from the National Health Insurance Research Database in Taiwan.

METHODS: We identified 1,023 adult patients with AD and 4,092 age- and sex-matched controls without allergic diseases in 2011. Using data from 71 Environmental Protection Agency monitoring stations across Taiwan, levels of exposure to air pollutants were determined by the location of a subject's place of residence. Multivariate logistic regression analysis, adjusted for age, sex, levels of urbanization, and family income, was performed.

RESULTS: We found an association between particulate matter <2.5 μm in diameter or the Pollutant Standards Index (the highest sub-index of the concentrations of 5 main air pollutants after transformation) and the development of adult AD. The adjusted odds ratios were 1.05 (95% confidence interval 1.02-1.08) and 1.02 (95% confidence interval 1.01-1.03), respectively.

CONCLUSION: These results demonstrated that air pollution, represented by particulate matter <2.5 μm in diameter or the Pollutant Standards Index, was modestly associated with the development of AD in adults.