PURPOSE OF THE STUDY.
Using prospectively collected data, this study sought to describe the natural history of peanut allergy in childhood and to provide thresholds for skin prick test (SPT) results and specific immunoglobulin E (sIgE) levels that predict probability of tolerance or persistence of peanut allergy.
This study included 1-year old infants with peanut allergy from the population-based, longitudinal HealthNuts study conducted in Australia.
Infants with challenge-confirmed peanut allergy (n = 156) were enrolled at 1 year of age and followed up at 4 years of age (n = 103) with SPTs, sIgE measurements, and oral food challenges (OFC) regardless of risk profile.
Peanut allergy resolved in 22% (95% confidence interval, 14%–31%) by age 4 years. At 1 year of age, SPT of ≥13 mm or sIgE ≥5 kIU/L predicted persistent peanut allergy, with positive predictive value (PPV) of 95%. At 4 years, SPT ≥8 mm and sIgE ≥2.1 kIU/L predicted persistent peanut allergy with PPV of 95%. SPT ≤8 mm and sIgE of ≤0.35 kIU/L each had 50% negative predictive value for resolution of peanut allergy at 4 years. All children with an increase in SPT size or sIgE level between ages 1 and 4 remained allergic; 47% and 26% of those with decrease in SPT size or sIgE level, developed tolerance, respectively. Factors not found to be predictive of persistent allergy to peanut included sensitization to other foods, atopic dermatitis, asthma, and sensitization to Ara h 2, tree nut, and dust mite.
This study reports a resolution rate of 22% in peanut-allergic children at age 4 years and provides SPT and sIgE values that will be useful in estimating probability of peanut tolerance at age 4 for years and in making decisions about whom should be offered OFC.
This study provides the first description of the natural history of peanut allergy between ages 1 and 4 years using prospectively collected data with oral food challenges at diagnosis and follow-up. Further study is needed to validate these SPT values and specific IgE levels in other geographic populations to help estimate probability of tolerance in older children and adults and to elucidate additional factors that may predict resolution of peanut allergy.
- Copyright © 2015 by the American Academy of Pediatrics