Saliva contact during infancy and allergy development in school-age children.

Abstract

Parent-child saliva contact during infancy might stimulate the child's immune system for effective allergy prevention. However, few studies have investigated its relation to allergy development in school-age children. We sought to investigate the relationship between parent-child saliva contact during infancy and allergy development at school age. We performed a large multicenter cross-sectional study involving Japanese school children and their parents. The self-administered questionnaires including questions from the International Study of Asthma and Allergies in Childhood were distributed to 3570 elementary and junior high school children in 2 local cities. Data were analyzed for the relationship between saliva contact during infancy (age <12 months) and the risk of allergy development, specifically eczema, allergic rhinitis, and asthma. For detailed Methods, please see the Methods section in this article's Online Repository at www.jacionline.org. The valid response rate was 94.7%. The mean and median age of children was 10.8± 2.7 and 11 (interquartile range, 9-13) years, respectively. Saliva contact via sharing eating utensils during infancy was significantly associated with a lower risk of eczema (odds ratio, 0.53; 95% CI, 0.34-0.83) at school age. Saliva contact via parental sucking of pacifiers was significantly associated with a lower risk of eczema (odds ratio, 0.24; 95% CI, 0.10-0.60) and allergic rhinitis (odds ratio, 0.33; 95% CI, 0.15-0.73), and had a borderline association with the risk of asthma in school-age children. Saliva contact during infancy may reduce the risk of developing eczema and allergic rhinitis in school-age children.