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Objective-To present methodology to identify atopic parents and determine the prevalence of sensitization to 15 aeroallergens in their infant offspring.Study design-A birth cohort of infants was identified from birth records; an infant was enrolled if 1 of the parents reported allergy respiratory symptoms and had a positive skin prick test (SPT) to a common aeroallergen. At age 1 year, these infants were tested to the same aeroallergens.Results-Of the 680 enrolled infants, 28.4% were SPT+ to 1 or more aeroallergens and/or food, and 18.0% were positive to 1 or more aeroallergens. By category of allergens, 9.7% were sensitized to pollens, 7.5% to molds, 4.3% to house dust mite and/or cockroach, and 3.4% to dog and/or cat. Of the infants who were positive to an aeroallergen, 65.7% remained positive at age 2 years.Conclusions-Infants born to atopic parents with percutaneous sensitization to aeroallergens are at increased risk for aeroallergen sensitization during infancy, which persists to age 2 years. These findings suggest that current clinical practices, which generally avoid skin testing before age 2 years, be reassessed in this population of high-risk children.In the Third National Health and Nutrition Examination Survey, (NHANES III), conducted in 1988-1994, 50% of children age 4 to 17 years exhibited a positive skin prick test (SPT) to at least 1 of 4 aeroallergens. 1 Over the last 2 decades, these high rates of aeroallergen sensitization have been accompanied by an estimated doubling in the incidence of allergic respiratory diseases, with an 11% gap for asthma attacks (26% vs 15%) between black and white children. 2,3 Aside from food allergies and atopic dermatitis, the potential for development of atopic respiratory disorders in infancy is often deemphasized, even though sensitization to allergens at younger ages has been shown to be more important than sensitization later in childhood for the development of wheezing symptoms and asthma. 4,5 Thus, early recognition of aeroallergen sensitization during the first and second years of life may facilitate surveillance of infants at highest risk for later expression of allergic respiratory disease. 6Although parental history of asthma and allergic rhinitis 7-9 are important risk factors for childhood asthma, 10-12 little is known about percutaneous sensitization profiles of infants born to parents with confirmed aeroallergen sensitization. This is due in part to the difficulties NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript inherent in performing the SPT in infants as well as parents, despite the fact that this procedure can be safely performed in patients of all ages and is more sensitive than in vitro measurements of serum-specific IgE. 13 Moreover, in all but 1 birth cohort study of infants in which SPT has been performed, the number of aeroallergens evaluated was 7 or less. 14-17Here we report methods used to precisely identify atopic parents and successfully recruit their high-risk infants for the Cincinnati Childhood All...

Rationale: Murine models demonstrate a synergistic production of reactive oxygen species on coexposure to diesel exhaust particles and endotoxin. Objectives: It was hypothesized that coexposure to traffic-related particles and endotoxin would have an additive effect on persistent wheezing during early childhood. Methods: Persistent wheezing at age 36 months was assessed in the Cincinnati Childhood Allergy and Air Pollution Study, a high-risk birth cohort. A time-weighted average exposure to traffic-related particles was determined by applying a land-use regression model to the homes, day cares, and other locations where children spent time from birth through age 36 months. Indoor levels of endotoxin were measured from dust samples collected before age 12 months. The relationship between dichotomized (,/>75th percentile) trafficrelated particle and endotoxin exposure and persistent wheezing, controlling for potential covariates, was examined. Measurements and Main Results: Persistent wheezing at age 36 months was significantly associated with exposure to increased levels of traffic-related particles before age 12 months (OR 5 1.75; 95% confidence interval, 1.07-2.87). Coexposure to endotoxin had a synergistic effect with traffic exposure on persistent wheeze (OR 5 5.85; 95% confidence interval, 1.89-18.13) after adjustment for significant covariates. Conclusions:The association between traffic-related particle exposure and persistent wheezing at age 36 months is modified by exposure to endotoxin. This finding supports prior toxicological studies demonstrating a synergistic production of reactive oxygen species after coexposure to diesel exhaust particles and endotoxin. The effect of early versus later exposure to traffic-related particles, however, remains to be studied because of the high correlation between exposure throughout the first 3 years of life.

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