Does Environment Mediate Earlier Onset of the Persistent Childhood Asthma Phenotype?
Objective. We investigated the role of environmental and hereditary factors in determining whether persistent childhood wheezing phenotypes had an early or late onset. Methods. In a whole population birth cohort (n = 1456), children were seen at birth and at 1, 2, 4, and 10 years. At each visit, information was collected prospectively regarding wheeze prevalence and used to classify subjects into wheezing phenotypes. Information on genetic and environmental risk factors in early life was also obtained prospectively, and skin-prick testing to common allergens was performed at 4 years. Results. Early-onset persistent wheezers (n = 125) had wheeze onset in the first 4 years, still present at age 10, whereas late-onset persistent wheezers (n = 81) had wheeze onset after age 4 years that was still present at 10 years. Multivariate logistic regression analysis identified independent significance only for inherited factors (parental asthma, family history of rhinitis, eczema at 4 years, and a
