BACKGROUND: We sought to determine the relationship between childhood eczema, climate and environmental pollutants.
METHODS: We analyzed data from the 2007-2008 National Survey of Children's Health including a representative sample of 91,642 children age 0-17 years and the 2006-2007 Environmental Protection Agency measurements of carbon monoxide (CO), nitrate (NO3 ), nitrogen dioxide (NO2 ), organic carbon (OC), sulfate (SO3 ), sulfur dioxide (SO2 ), particulate matter ≤2.5 micrometer (PM-2.5) and <10 micrometer (PM-10) and tropospheric ozone levels, and the National Climate Data Center measurements of relative humidity (%), issued UV index, outdoor air temperature and precipitation levels.
RESULTS: In multivariate survey logistic regression models controlling for age, sex, race/ethnicity, household income, US birthplace and history of moving to a new location, eczema was associated with higher mean annual NO2 (P=0.008), SO2 (P=0.006), SO3 (P=0.0002), arsenic (P=0.0007), nickel (P=0.0002), lead (P=0.03), vanadium (P<0.0001) and zinc (P=0.003), but lower NO3 (P=0.002), OC (P=0.03), PM-2.5 (P=0.006), cadmium (P<0.0001), copper (P=0.004) and potassium (P<0.0001). In contrast, moderate-severe eczema was associated with higher NO3 (P=0.03), OC (P=0.008) and PM-2.5 (P=0.01), copper (P=0.04), lead (P=0.008) and zinc (P=0.01), but lower CO (P=0.03). Principal component analysis was used and identified 4 combinations of pollutants and climate factors occurring in the US, of which 1 was associated higher prevalence and 2 were associated with lower prevalences of eczema (P<0.05).
CONCLUSIONS: Pollutants in conjunction with climate factors may differentially impact eczema prevalence and severity, some with apparent harmful effects. This article is protected by copyright. All rights reserved.
eczema prevalence; eczema severity; atopic dermatitis; small-particle air pollution; air pollutants; nitrate; nitrogen dioxide; sulfate; sulfur dioxide; ozone; particulate matter under 2; 5 m; particulate matter under 10 m; climate; relative humidity; ultraviolet index; air temperature; pediatric; children