More than half of America suffers from allergies, study says

• More than half (54.3 percent) of the U.S. population is sensitive to one or more common allergens, placing them at increased risk for the development of asthma, hay fever, and eczema.
• The highest prevalence rates were for dust mite, rye, ragweed, and cockroach, with about 25 percent of the population testing positive to each allergen.
• Roughly 18 percent reacted to Bermuda grass, 17 percent to cat, 15 percent to Russian thistle, and 13 percent to white oak and mold.
• Peanut allergy was the least common, with 8.9 percent of subjects having a positive skin test response.
• The findings, published in the Journal of Allergy and Clinical Immunology, are based on results of allergy skin tests performed on roughly 10,500 U.S. adults as part of the third National Health and Nutrition Examination Survey (NHANES III).
• For the 6 allergens common to both surveys, the prevalence of a positive skin test was 2.1 to 5.5 times higher in NHANES III than in NHANES II, the investigators report.
• However, due to differences in skin test procedures between the two surveys, it cannot be definitively concluded that the increases in positive skin test response rates observed between the two surveys reflect a true rise in the prevalence of allergic reactions in the US population.
• Nonetheless, the researchers say such an increase "would be consistent with studies from other countries."
• An individual with a positive skin test result may be more vulnerable to developing asthma, hay fever, and eczema.
• "Asthma is one of the world's most significant chronic health conditions, David A. Schwartz of the NIEHS noted in a statement.
• "Understanding what may account for the rising worldwide asthma rates will allow us to develop more effective prevention and treatment approaches," he added.