Acknowledgments
We acknowledge the founders of the TAHS; National Health and Medical
Research Council (NHMRC) of Australia (research grants 299901 and
1021275); the University of Melbourne, Clifford Craig Medical Research
Trust of Tasmania; the Victorian, Queensland and Tasmanian Asthma
Foundations; Royal Hobart Hospital; Helen MacPherson Smith Trust;
GlaxoSmithKline; and John L Hopper. D. Lopez was supported by the
University of Melbourne and Becas Carlos Antonio Lopez scholarship. The
funding agencies had no direct role in the conduct of the study, the
collection, management, statistical analysis and interpretation of the
data, preparation or approval of the manuscript.
Main text word count: 3495
Abstract
Background: There is limited information on risk factors for
eczema in adults. Recent evidence suggests that air pollution may be
associated with increased incidence of eczema in adults. We aimed to
assess this possible association.
Methods: Ambient air pollution exposures (distance from a major
road, nitrogen dioxide [NO2], fine particulate
matter with an aerodynamic diameter ≤2.5 µm [PM2.5])
were assessed for the residential address of Tasmanian Longitudinal
Health Study participants at ages 43 and 53 years. Eczema incidence
(onset after age 43 years), prevalence (at 53 years) and persistence
were assessed from surveys, while sensitisation was assessed using skin
prick tests. The presence or absence of eczema and sensitisation was
classified into four groups: no atopy or eczema, atopy alone, non-atopic
eczema, and atopic eczema. Adjusted logistic and multinomial regression
models were fitted to estimate associations between ambient air
pollution and eczema, and interaction by sex was assessed.
Results: Of 3153 participants in both follow ups, 2369 had valid
skin prick tests. For males, a 2.3 ppb increase in baseline
NO2 was associated with increased risk of prevalent
eczema (OR=1.15 [95%CI 0.98-1.36]), both non-atopic (OR=1.39
[1.02-1.90]) and atopic eczema (OR=1.26 [1.00-1.59]). These
associations were not seen in females (P for interaction=0.08,
<0.01). For both sexes, a 1.6 µg/m3 increase
in PM2.5 exposure at follow-up was associated with
increased odds of aeroallergen sensitisation (OR=1.15 [1.03-1.30]).
Conclusion: Increased
exposure to residential ambient air pollutants was associated with an
increased risk of eczema, only in males, and aeroallergen sensitisation
in both genders.
Keywords: adults, atopy, dermatitis, eczema, middle-age, ambient
air pollution
Word count: 249