Hay fever and asthma in relation to markers of infection in the United States

Abstract

Background: The hygiene hypothesis proposes that declining exposure to infections is implicated in the rising trend of allergy and asthma. Objective: We sought to test this hypothesis by examining the relationship of hay fever, asthma, and atopic sensitization with markers of infection in a large general population sample of the United States. Methods: We analyzed the data of 33,994 US residents recorded in a public database of a nationally representative cross-sectional survey (Third National Health and Nutrition Examination Survey, 1988-1994). The variables examined were sociodemographic information, lifetime diagnosis and age at first diagnosis of hay fever or asthma, current skin sensitization to 9 airborne allergens and peanut, and current serology for Toxoplasma gondii, herpes simplex viruses type 1 and 2, and hepatitis A, B, and C viruses. Results: Hay fever (adjusted odds ratio, 0.27; 95% CI, 0.18-0.41; P