Atopic disease in preadolescence ‐ an evaluation of questionnaires, association with cord blood IgE and month of birth

During a prospective study of 1654 children, followed from birth for 11 years, we evaluated the validity of a detailed questionnaire for establishing the prevalence of atopic disease in preadolescence. In 133 randomly selected children the questionnaire‐based diagnoses were accurate in 128 (96.2%). If the cord blood IgE concentration was high (? 0.9 kU/l) then it was 1.7 times more common to have any prevalent atopic disease. The corresponding relative risk for multiple atopic disease was 11.5. Boys had high IgE levels significantly more often than girls, regardless of the degree of pubertal maturation. Sensitization to timothy pollen developed more often in children born during May compared to November. At least one allergy test (IgE, Phadiatop or SPT) was positive in 20 of 70 (28.6%) 11‐year‐old children with no history of atopic disease, indicating latent allergy. Among the healthy children with positive tests, those with cord blood IgE ? 1.3 kU/l were over‐represented. IgE concentrations at 11 years of age corresponded poorly with neonatal IgE concentrations, indicating that after birth environmental influences are more important for the present IgE level than genetic factors.