Indoor environment, atopy and the risk of the asthma in children in New Zealand.

The objective of this study was to examine the relationship between the indoor environment, atopy and asthma in 7-9-year-old children. Cases and controls were randomly selected from children who participated in the International Study of Asthma and Allergies in Childhood (ISAAC) in Wellington, New Zealand. Cases were children with a previous diagnosis of asthma and current medication use (n = 233) and controls were children with no history of wheezing and no diagnosis of asthma (n = 241). Information was recorded about the indoor environment during the first year of life and currently. Dust was sampled from floors and beds and Der p 1 and Fel d 1 measured using enzyme-linked immunosorbent assays. Skin-prick tests were performed with eight common allergens. Sensitization to Dermatophagoides farinae (OR = 3.19; 95% CI 1.74-5.84), Dermatophagoides pteronyssinus (OR = 2.06; 95% CI 1.16-3.65) and cat (OR = 3.89; 95% CI 1.06-14.30) were independently associated with current asthma. The use of a sheepskin in the first year of life (OR = 1.91; 95% CI 1.11-3.33) was also independently associated with current asthma but current Der p 1 levels showed no association with current asthma. Exposures in early life may be more important than current exposures in determining asthma at age 7-9 years. Prospective studies are needed in New Zealand to determine the relative importance of early life exposures to Der p 1 and other risk factors for asthma.