Prevalence of specific allergic diseases in school children as related to parental atopy.

Abstract

Our objective was to investigate the influence of parental allergy on the manifestations and course of allergic disease in children. A total of 15,234 school children aged 6 and 9 years were evaluated by means of questionnaires completed by their parents in a cross-sectional survey conducted in Tokushima, Japan. The prevalence and relative risk ratio (RRR) for parental allergy in children with atopic dermatitis, asthma and allergic rhinitis were 6.4% (RRR 2.5), 3.2% (RRR 2.4) and 15% (RRR 2.4), respectively. The risk of atopic dermatitis was particularly high in children whose parent had atopic dermatitis, with an RRR of 2.8 (father) and 3.7 (mother). Children with a parental history of asthma also had a high risk of that disorder (RRR of father 5.3, mother 6.2). However, the risk of allergic rhinitis was no different in children with a parental history of allergic rhinitis or from children with a parental history of asthma and atopic dermatitis. A history of allergic disease in both parents, especially of asthma and atopic dermatitis, increased the risk of allergic disease in the child. Milder symptoms, such as wheezy bronchitis, in schoolchildren were similarly related with the same hereditary tendency as the identical allergic disease. The disappearance of allergic symptoms with age also related to a hereditary component, being less likely in children with a history of parental allergy than in those without such an atopic history. The manifestations and course of allergic disease in school children relate to parental allergic disease.