Background: Allergic diseases are more prevalent in affluent countries, which has been attributed to life-style factors. Life-style habits may also differ between socioeconomic (SES) classes. The objective of this paper therefore was to evaluate if SES had an impact on the development of atopic disorders.
Methods: A total of 1314 German children were followed-up in an observational birth cohort study to 6 years of age. Parents filled in questionnaires, and had multi-allergen screening tests for sensitization. Indoor allergen concentrations were determined by ELISA. Children were examined regularly up to 6 years, specific serum IgE values were determined by CAP-Rast-Feia.
Results: The risk of aeroallergen sensitization (odds ratio 1.76; 95% CI 1.30-2.37), and the lifetime prevalence of hay fever (2.36; 1.76-3.17), and asthma (1.74; 1.08-2.80), but not of atopic dermatitis (AD: 0.90; 0. 54-1.51) was elevated in parents of high compared to low SES. With high SES the risk of smoking in pregnancy (0.35; 0.23-0.51), in the home (0.31; 0.21-0.46), pet ownership (0.37; 0.26-0.55), high mite (0.42; 0.25-0.74), and high cat (0.38; 0.18-0.82) allergen concentration in house dust was reduced, but elevated for breastfeeding over more than 6 months (4.67; 2.9-7.48). In children, even after controlling for other risk factors, only the risk of AD from 3 to 6 years (2.42; 1.42-4.14) was elevated in families with high SES, but not of AD in infancy or of any other atopic disorder.
Conclusions: While parents of high SES have a higher prevalence of inhalative allergies, their favourable life-style prevents the development of atopic disorders in their children, except for AD beyond infancy.