Despite vast differences of environment, a new study finds that overall allergy prevalence is the same across different regions of the United States. The one exception is that children aged 5 and under living in the southern states are more likely to be allergic.
“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.,” said lead study author Dr. Darryl Zeldin, from the National Institutes of Health.
“This study suggests that people prone to developing allergies are going to develop an allergy to – whatever is in their environment.”
For the study, scientists examined blood test results from 10,000 Americans from the National Health and Nutrition Examination Survey. They found that 45 percent of people aged 6 years old or older had detectable IgE specific to one or more of 19 food or environmental allergens.
While there was no difference in overall allergy prevalence by region, it was found that what people were specifically allergic to did vary by geographic location. For example, sensitization to indoor allergens, like dust mite and cockroach, was more prevalent in the South, while outdoor allergies were more likely in the western states. Food allergies were also found to be more prevalent  in the South.
The study suggests that moving to a new region isn’t likely to help with allergies.