PURPOSE OF STUDY.
The authors aim to compare the performance of skin prick test (SPT) and specific immunoglobulin E (sIgE) in 2-year-old children for predicting allergic disease at 6 years of age.
Participants were part of the Prevention of Allergy among Children in Trondheim (PACT) study, a large birth cohort study of the incidence of allergic disease in children conducted in Norway.
Two-year-old children were examined and parents were interviewed regarding the presence of allergic disease. Atopic dermatitis (AD) was assessed by both examination and the UK Working Party’s Criteria; severity of AD was assessed by using the Nottingham Eczema Severity Score. Asthma and allergic rhinitis (AR) were assessed by questions only. SPT and/or sIgE to foods (milk, egg, fish, peanut, hazelnut) and inhalants (dog, cat, birch, timothy) were performed. At 6 years of age, the children were again evaluated and the parents completed an identical questionnaire.
Complete data were available for 199 children, and incomplete data were available for another 469 children. Of the children with allergic disease at age 2, half no longer had allergic disease at age 6 years. The biggest predictor of allergic disease at age 6 years was allergic disease at age 2 years (odds ratio 4.7, 95% confidence interval: 2.4–9.5). In 2-year-old children without allergic disease, a positive SPT or sIgE was associated with increased odds of any allergic disease (AD, AR, asthma), with a positive predictive value of 50% with a positive SPT and 67% with a positive sIgE. There were no significant differences between food and inhalant sensitization as a predictor for allergic disease at age 6. There were no statistically significant differences between SPT and sIgE in terms of their ability to predict any allergy-related disease with the exception of allergic rhinoconjunctivitis, in which sIgE was significantly more predictive of disease at age 6 years than SPT (P = .03).
The authors conclude that sensitization at age 2 years as determined by SPT or sIgE may predict allergic disease in later childhood and that with the exception of allergic rhinoconjunctivitis, SPT and sIgE were similarly predictive.
This study demonstrates in a large group of children that evidence of sensitization by means of SPT and sIgE at age 2 years has a positive predictive value of 50% to 67% for the presence of allergic disease at age 6 years, with SPT and sIgE being similarly predictive. sIgE appears to be more predictive of allergic rhinoconjunctivitis at age 6 than SPT. This information could be useful for early identification and intervention to reduce pediatric morbidity from allergic disease.
- Copyright © 2015 by the American Academy of Pediatrics