Allergy Rates Surprisingly Similar Across the U.S., Study Finds

Wherever you live in the United States, allergy rates are mostly the same, but young children in southern states are more likely to suffer allergies than their peers in other places.

That's the finding of a government study that looked at blood-test data from about 10,000 people included in the 2005-2006 National Health and Nutrition Examination Survey.

"Before this study, if you would have asked 10 allergy specialists if allergy prevalence varied depending on where people live, all 10 of them would have said yes, because allergen exposures tend to be more common in certain regions of the U.S.," Dr. Darryl Zeldin, scientific director of the National Institute of Environmental Health Sciences, said in an agency news release.

"This study suggests that people prone to developing allergies are going to develop an allergy to whatever is in their environment. It's what people become allergic to that differs," he explained.

While the overall rate of allergies was about the same in all regions of the United States, children aged 1 to 5 years in southern states had higher allergy rates than those in other parts of the country, the investigators found.

Those states were Texas, Oklahoma, Louisiana, Arkansas, Tennessee, Kentucky, Mississippi, Alabama, Georgia, West Virginia, Virginia, North Carolina, South Carolina, and Florida.

"The higher allergy prevalence among the youngest children in southern states seemed to be attributable to dust mites and cockroaches," study author Paivi Salo, an epidemiologist in Zeldin's research group, said in the news release.

"As children get older, both indoor and outdoor allergies become more common," Salo added, "and the difference in the overall prevalence of allergies fades away."

The study, published online recently in the Journal of Allergy and Clinical Immunology, also found that people aged 6 years and older, males, blacks and those without pets were more likely to have allergies.

Social and economic status did not appear to influence allergy risk, but richer people were more likely to be allergic to dogs and cats, while poorer people were more likely to be allergic to cockroaches and shrimp, the findings showed.

More information

The U.S. National Library of Medicine has more about allergies.