Nonatopic eczema in elderly women: Effect of air pollution and genes

Background: Although many risk factors have been described for atopic eczema in children, little is known about the eczema phenotype in middle-aged or elderly adults. Objective: We sought to examine the association between air pollution, atopy, and eczema in adulthood. Methods: This analysis was based on 834 women from the Study on the influence of Air pollution on Lung Function, Inflammation and Ageing cohort in Germany. Incident symptoms of eczema after age 55 years and prevalent symptoms of eczema 12 months or less before investigation were assessed by means of questionnaire at the second follow-up (2007-2010). Total serum IgE levels were measured at baseline (1985-1994) and in 2007-2010. Exposure to air pollution was assessed by using land-use regression. Adjusted logistic regression models were applied to estimate the association between air pollution and incident and prevalent symptoms of eczema. Weighted genetic risk scores were used to investigate the effect of atopic eczema–related risk alleles on this association. Results: Exposures to oxides of nitrogen (nitrogen dioxide and nitrogen oxides) and particulate matter (fine particulate matter with an aerodynamic diameter of ≤2.5 μm [PM_2.5] and particulate matter with an aerodynamic diameter of <10 μm) were significantly associated with increased odds of incident eczema (eg, with PM_2.5 per 4.7 μg/m³; odds ratio, 1.45; 95% CI, 1.06-1.99). These associations were slightly more pronounced with nonatopic eczema (eg, with PM_2.5; odds ratio of 1.65 and 95% CI of 1.15-2.34 for participants without hay fever or increased IgE levels). Associations with air pollution were stronger in carriers of fewer risk alleles for atopic eczema. Conclusion: Nonatopic eczema in the elderly is associated with traffic-related air pollutants, and this phenotype differs from genetically driven atopic eczema.