Treatment with antibiotics in the neonatal period was an independent risk factor for wheezing that was treated with inhaled corticosteroids at 12 months of age. These results indirectly support the hypothesis that an alteration in the intestinal flora can increase the risk of subsequent wheezing.

Background: Atopic eczema in infants has increased in western societies. Environmental factors and the introduction of food may affect the risk of eczema. Aims: To investigate the prevalence of eczema among infants in western Sweden, describe patterns of food introduction and assess risk factors for eczema at 1 year of age. Methods: Data were obtained from a prospective, longitudinal cohort study of infants born in western Sweden in 2003; 8176 families were randomly selected and, 6 months after the infant's birth, were invited to participate and received questionnaires. A second questionnaire was sent out when the infants were 12 months old. Both questionnaires were completed and medical birth register data were obtained for 4921 infants (60.2% of the selected population). Results: At 1 year of age, 20.9% of the infants had previous or current eczema. Median age at onset was 4 months. In multivariable analysis, familial occurrence of eczema, especially in siblings (OR 1.87; 95% confidence interval (CI) 1.50 to 2.33) or the mother (OR 1.54; 95% CI 1.30 to 1.84), remained an independent risk factor. Introducing fish before 9 months of age (OR 0.76; 95% CI 0.62 to 0.94) and having a bird in the home (OR 0.35; 95% CI 0.17 to 0.75) were beneficial.

Allergic heredity plays a major role in the development of allergic rhinitis. In addition the introduction of food may influence the risk of subsequent allergic disease. The aim of this study was to analyse early risk factors and protective factors for allergic rhinitis at preschool age. Data were obtained from a prospective, longitudinal study of a cohort of children born in the region of western Sweden in 2003 and 8,176 families (50% of the birth cohort) were randomly selected. The parents answered questionnaires at 6 and 12 months and at 4½ yr of age. The response rate at 4½ yr was 4,496, i.e. 83% of the 5,398 questionnaires distributed at 4½ yr. At 4½ yr of age, 5.5% reported symptoms of allergic rhinitis during the last year. In the multivariate analysis, independent risk factors for allergic rhinitis were: allergic sensitisation to food allergens at 4½ yr (OR 10.21; 95% confidence interval 4.22–24.73), recurrent wheeze at 4½ yr (3.33; 1.56–7.10), doctor-diagnosed eczema at 4½ yr (2.72; 1.62–4.55), parental rhinitis (2.21; 1.39–3.53), eczema first year (1.97; 1.19–3.26) and male gender (1.82; 1.13–2.94). The risk was reduced with fish introduction before 9 months (0.49; 0.29–0.82). In conclusion, we found that previous and present allergic disease, heredity and male gender increased the risk of allergic rhinitis at 4½ yr of age. The introduction of fish before the age of 9 months reduced the risk.

BackgroundThe early introduction of fish has been reported to reduce the risk of wheezing disorder in early childhood, while broad-spectrum antibiotics in the first week have been associated with an increased risk. However, it is uncertain whether the effects remain into school age. The aim was to explore these risk factors for doctor-diagnosed asthma at 8 years.MethodsData were obtained from a prospective, longitudinal study of a cohort of children born in western Sweden. The parents answered questionnaires at 6 months and 1, 4.5 and 8 years of age. The response rate at 8 years was 80% of the questionnaires distributed (4051/5044), that is, 71% of the families entering the study (4051/5654).ResultsAt 8 years, 5.7% reported current doctor-diagnosed asthma. Of these, 65% had atopic asthma and 35% non-atopic asthma. In the multivariate analysis, atopic heredity, male gender and own allergic disease during infancy were risk factors for doctor-diagnosed asthma at 8 years. In addition, the introduction of fish before the age of 9 months independently reduced the risk (adjusted OR 0.6; 95% CI 0.4–0.96), while broad-spectrum antibiotics in the first week independently increased the risk of current asthma at school age (aOR 2.3; 1.2–4.2). Regarding types of asthma, the effects were significant in atopic asthma but not in non-atopic asthma.ConclusionThe early introduction of fish and neonatal antibiotic treatment influence the risk of asthma into school age. The significant effect on atopic asthma is of particular importance, as this phenotype is of major clinical significance.