PURPOSE OF THE STUDY.
To evaluate the relation between early presence of low levels of specific immunoglobulin E (s-IgE) sensitization to food and inhalant allergens and the development of allergic diseases during childhood.
Study subjects included 268 children born between 1997 and 2000 who were part of a prospective study cohort. All children were born term and healthy. One-third of the children had 2 parents with allergy, one-third had mothers with allergy, and one-third had parents with no allergy, suggested by history and confirmed by results of skin prick testing.
The children were followed up prospectively from birth to 5 years and had clinical evaluations at 6, 12, 18, and 24 months and 5 years for the development of eczema, wheezing or asthma, and rhinoconjunctivitis. s-IgE against hen’s egg white, cow’s milk, codfish, peanut, soybean, cat, dog, Dermatophagoides farinae, birch pollen, and timothy pollen was assessed at each visit by using the ImmunoCAP System (Phadia AB, Uppsala, Sweden). Low levels of allergen s-IgE included concentrations between 0.1 and 0.7 kU/L.
The most common s-IgE sensitizations at all ages were to egg and milk, and the presence of s-IgE to all allergens increased with increasing age. Low levels of s-IgE to milk and egg were related to eczema and further allergic sensitization at the age of 5 years. No relations between low levels of s-IgE at 6 and 12 months and respiratory symptoms at 5 years were found.
Children with low levels of s-IgE sensitization to food allergens had an increased risk of developing eczema by 24 months. Early-onset low levels of s-IgE can be related to further IgE sensitization during childhood.
With improved testing technology, it is now possible to accurately measure s-IgE concentrations as low as 0.1 kU/L. This study describes the importance of low levels of s-IgE in relation to symptoms being most pronounced at young ages. However, further investigation is needed to determine the clinical implication of low-level s-IgE sensitization as a diagnostic and predictive measure for atopic disease in childhood. The interpretation and clinical implication of early testing of s-IgE concentrations is challenging because the presence of s-IgE sensitizations often do not correlate with clinical symptoms. Due to this complexity, suspicion of atopic disease in children should lead to further evaluation by an allergy specialist.
- Copyright © 2012 by the American Academy of Pediatrics