THE PREVALENCE OF AND RISK-FACTORS FOR ATOPY IN EARLY-CHILDHOOD - A WHOLE POPULATION BIRTH COHORT STUDY

Objectives: A birth cohort was followed-up to age 4 years to record th e development of allergic disorders and to study the influence of gene tic and environmental factors. Methods: Information on family history and environmental factors was obtained at birth, and serum cord IgE wa s measured. At age 4 years, 1218 children were reviewed. Results: By a ge 4 years, 27% of the children had symptoms of allergic disease. Peri od prevalence of asthma increased from 8.7% in infancy to 14.9% at 4 y ears; Family history of atopy was the single most important risk facto r for atopy in children. Sibling atopy was a stronger predictor of cli nical disease than maternal dr paternal atopy, whereas paternal atopy, male sex, and high cord IgE were significant for the development of a llergen sensitization. Children of asthmatic mothers were three times more likely to have asthma (odds ratio [OR]: 3.0, 95% confidence inter val [CI]: 1.6-5.8) and rhinitis (OR: 2.9, CI: 1.1-7.4). Formula feedin g before 3 months of age predisposed to asthma at age 4 years (OR: 1.8 , CI: 1.2-2.6). The effect of maternal smoking on childhood wheeze see n at 1 and 2 years was lost by age 4, except for a subgroup with negat ive skin test responses (nonatopic asthma). Less than half (46%) of th e infantile wheezers were still wheezing at 4 years of age. Conclusion : Family history of atopy remains the most important risk factor for a topy in children, but other markers can be identified with a potential for Intervention at an early age.