(HealthDay) -- The prevalence of asthma, hay fever, and allergic sensitization is significantly lower among the Amish population than among Swiss children, according to a study presented at the annual meeting of the American Academy of Allergy, Asthma & Immunology, held from March 2 to 6 in Orlando, Fla.
Mark Holbreich, M.D., from Allergy and Asthma Consultants in Indianapolis, and colleagues investigated the prevalence of asthma, hay fever, and allergic sensitization among children in Swiss and Amish populations. A total of 28,686 questionnaires were distributed to families in Switzerland with children aged 6 to 12 years. Consenting children were evaluated for serum specific immunoglobulin E (IgE) to allergens. Among the Amish, a questionnaire was completed and children were invited to a skin prick test.
The researchers note that 65 percent of the questionnaires were returned in Switzerland and 85 percent were returned among the Amish. IgE measurements and skin prick testing were carried out in 89 and 75 percent, respectively. For the Amish, Swiss farm, and Swiss non-farm children, the researchers found that the prevalence of asthma was 5.2, 6.8, and 11.3 percent, respectively, and the prevalence of atopy was 7.2, 25.2, and 44.2 percent, respectively.
"The prevalence of asthma, hay fever and allergic sensitization in the Amish population is substantially lower that among Swiss farm children and lower than in most population studies. Traditional farm exposures and large family size may account for this impressive protective effect," the authors write.
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Abstract No. 494