Environmental factors differentially influence the persistence or remission of infantile wheezing during the first three years of life

Abstract

Rationale The identification of environmental risk factors that influence the differentiation of wheezing phenotypes in early childhood is important to the study of asthma pathogenesis in children. Methods 269 children with at least one atopic parent enrolled in the COAST (Childhood Origins of ASThma) study were followed prospectively from birth to 3 years of age. Data were collected using serial questionnaires and examinations permitting an evaluation of the timing and nature of multiple environmental exposures. These exposures were then examined for their association with the following 2 groups of children: those who only wheezed during the first year of life [infantile wheezers (IW); n=49], and those that began wheezing during infancy and continued to wheeze until at least 3 years of age [recurrent wheezers (RW); n=45]. Results Exclusive formula feeding (29% vs. 11%; p=0.04) and dog (not cat) ownership (41% vs. 22%; p=0.05) were more common in infantile wheezers. Recurrent wheezers were more likely to have active atopic dermatitis at age 1 yr (36% vs. 16%; p=0.03). Recurrent wheezers tended to be exposed more often to smoke (38% vs. 22%; p=0.10) and to have one or more older siblings (76% vs. 61%; p=0.14). Daycare exposure was comparable in the two groups (RW 56% vs. IW 51%; p=0.66). Conclusion During early childhood, various environmental exposures differentially influence the persistence or remission of wheezing that begins during infancy.