Importance: Improved understanding of allergic disease epidemiology lead to novel therapeutic and prevention strategies.
Objectives: To study the association between US birthplace and prevalence of childhood allergic disease and to determine the effects of prolonged US residence on allergic disease.
Design, setting, participants: Cross-sectional questionnaire distributed to 91, 642 children aged 0 to 17 years enrolled in the 2007-2008 National Survey of Children's Health.
Exposure: Place of birth.
Main outcome and measure: Prevalence of allergic disease, including asthma, eczema, hay fever, and food allergies.
Results: Children born outside the United States had significantly lower odds of any atopic disorders than those born in the United States (logistic regression OR, 0.48; 95% CI, 0.38-0.61), including ever-asthma (0.53; 0.39-0.72), current-asthma (0.34; 0.23-0.51), eczema (0.43; 0.30-0.61), hay fever (0.39; 0.27-0.55), and food allergies (0.60; 0.37-0.99). The associations between child's birthplace and atopic disorders remained significant in multivariate models including age, sex, race/ethnicity, annual household income, residence in metropolitan areas, and history of child moving to a new address. Children born outside the United States whose parents were also born outside the United States had significantly lower odds of any atopic disorders than those whose parents were born in the United States (P = .005). Children born outside the United States who lived in the United States for longer than 10 years when compared with those who resided for only 0 to 2 years had significantly higher odds of developing any allergic disorders (adjusted OR, 3.04; 95% CI, 1.08-8.60), including eczema (4.93; 1.18-20.62; P = .03) and hay fever (6.25; 1.70-22.96) but not asthma or food allergies (P ≥ .06).
Conclusions and relevance: Children born outside the United States have a lower prevalence allergic disease that increases after residing in the United States for 1 decade.