Children born outside the United States have lower rates of allergies, but after prolonged U.S. residence, reduced prevalence is reversed, researchers say.
Dr. Jonathan I. Silverberg of St. Luke's-Roosevelt Hospital Center and colleagues at the State University of New York Downstate Medical Center and Oregon Health Science Center examined a sample of nearly 92,000 children from the 2007-08 National Survey of Children's Health.
They investigated if there was an association between birthplace, length of U.S. residence and rates of asthma, eczema, hay fever and food allergy.
After statistical analysis of the sample, the researchers found compared with the U.S.-born children, the children born outside the United States indeed had lower rates of allergic disease.