According to research published online in the Journal of Allergy and Clinical Immunology in February 2014, allergy prevalence in adults and children over the age of 6 is comparable among different regions of the United States. Prior to the analysis of data from the National Health and Nutrition Examination Survey 20052006, conventional thinking among allergy specialists was that the prevalence of allergies varied, depending on region.
This study was conducted by the National Institute of Environmental Health Sciences (NIEHS) of the National Institutes of Health (NIH) and was the largest, most comprehensive study on allergy prevalence to date in the United States. It involved about 10,000 people and showed that those who are prone to allergies will develop them to whichever allergens they are exposed to in their particular environment.
Researchers analyzed allergy blood test results for 9 antibodies in children aged 1 to 5, and nineteen antibodies in adults and children over the age of 6. They looked at a larger number of allergens across a wider age range and assessed more informationfor example, the extent of allergic reactions/sensitizationthan in previous studies.
While researchers determined that the overall prevalence of allergies does not vary from region to region, they did find a difference in children between the ages of 1 and 5. In this age group, children in the southern United States developed allergies more often than those living in other areas.
States with a higher allergy prevalence in children 1 to 5 years of age include the following:
- North Carolina
- South Carolina
- West Virginia
In addition to the findings above, researchers also found that certain factors increase allergy risk in people over the age of 6. According to the study, males, non-Hispanic blacks, and people who avoid contact with pets are at the highest risk for allergies.
In adults, socioeconomic status (SES)social standing or class as determined by a combination of education, income, and occupationdoes not predict allergy risk, but research shows that people in higher classes are most often allergic to dogs and cats, and those in lower classes are frequently allergic to shrimp and cockroach debris.
The study also disclosed regional differences in the prevalence of certain types of allergies. For example, indoor allergies and food allergies are more common in the southern United States and outdoor allergies are more common in the West.
Ongoing research is being conducted to further evaluate the effects of the environment on health and examine the possible link between exposure to allergens and overall well-being.
Source: National Institutes of Health (NIH)