Children born outside the United States have lower rates of allergic disease, but their risk for developing allergic conditions increases threefold after living in America for a decade.
By studying a sample of 91,000 children from the 2007-2008 U.S. National Survey of Children’s Health, researchers found that children who had been born in another country had lower overall rates of asthma, eczema, hay fever and food allergies. However, that trend reversed for eczema and hay fever (but not food allergies and asthma) as time went on.
Foreign-born children who had lived in the U.S. for more than 10 yearswere found to be more likely to develop hay fever and eczema than those who had been here for up to two years.
“Seeing this loss of childhood protection from eczema and hay fever implies that environmental factors may promote the development of allergic disease,” said Dr. Jonathan Silverberg of New York, lead author of the study presented at this year’s AAAAI meeting.