Air-tight homes may be fueling rise in allergies

A new study finds more people testing positive for allergens. Attention is turning to culprits in the great indoors.

By Susan J. Landers, AMNews staff. Sept. 12, 2005.

Washington -- Allergies may be poised to affect even greater numbers of people, and could increase vulnerabilities to asthma, hay fever and eczema.

Findings based on data from the third National Health and Nutrition Examination Survey (NHANES-III) show that more than 54% of 6- to 59-year-old participants tested positive to at least one allergen, with reactions to dust mite, rye, ragweed and cockroach allergens the most common. Reactions to peanut allergens were least common.

In addition, the researchers found that the number of positive skin tests had greatly increased since an earlier survey, NHANES-II, was conducted.

The large NHANES nationally representative surveys are conducted periodically by the Centers for Disease Control and Prevention to assess the health and nutritional status of the U.S. population. These most recent findings, sponsored by the National Institute of Environmental Health Sciences and the National Institute of Allergy and Infectious Diseases, were published in the August Journal of Allergy and Clinical Immunology.

No one really knows why allergies and asthma are on the increase, although there are a number of theories. But their rise could mean more than runny noses and sneezing and could be connected to the recent increase in the number of people with asthma, said the researchers.

"Asthma is one of the world's most significant chronic health conditions," said NIEHS Director David A Schwartz, MD. "Understanding what may account for the rising worldwide asthma rates will allow us to develop more effective prevention and treatment approaches."