In the largest, most comprehensive, nationwide study to examine the prevalence of allergies from early childhood to old age, scientists from the National Institutes of Health (NIH) report that allergy prevalence is the same across different regions of the United States, except in children 5 years and younger.

“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 Darryl Zeldin, M.D., scientific director of the National Institute of Environmental Health Sciences (NIEHS), part of NIH. “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.”