PURPOSE OF THE STUDY.
The goal of this study was to investigate factors associated with development of tolerance to 9 common food allergens.
The study population included 40 000 households with children in the United States.
A randomized, cross-sectional survey was completed by eligible adult caregivers regarding a child in the home. Allergies to the 9 most frequently reported current and outgrown food allergens (milk, peanut, shellfish, tree nut, egg, fish, wheat, soy, and sesame) were analyzed. Data regarding the age of first reaction, age at which the allergy was outgrown, and severity of the reaction (mild, moderate, or severe) were obtained.
Of the total 38 840 final surveys regarding children submitted, 8.3% of children had current food allergies, whereas 3.2% had outgrown food allergies. The data showed an average age of 3.6 years for the first reaction to any food. However, the mean age of the first reaction was younger for milk, egg, and soy reactions. Overall, the mean age for outgrowing food allergy was 5.4 years, although a younger mean age of tolerance was reported for milk, wheat, egg, and soy. Significantly higher frequency of tolerance was seen in milk, egg, or soy allergy, in contrast to those with shellfish, tree nut, and peanut allergies. Factors such as gender and race also influenced odds of tolerance, with boys having a higher tolerance rate than girls and a higher number of white versus black children reporting tolerance. Children with multiple food allergies showed significantly lower odds of developing tolerance, whereas those with a single food allergy had increased odds of tolerance. A higher probability of tolerance was seen with younger age of first reaction, as well as when eczema was the sole symptom of the food allergy. Children with severe reactions were less likely to have outgrown the food allergy.
Many factors (including the type of food, age at onset of reaction, race, and gender) may be associated with outgrowing food allergies.
Future tolerance of the food allergen(s) is one of the most frequently asked questions by caregivers of newly diagnosed children. Although this study has limitations, including the lack of oral challenge and likely recall bias, information about possible factors that may predict tolerance are described. Prospective studies investigating the natural history of food allergy will further aid the clinician in addressing the concerns of parents and would provide practitioners a larger scope of evidence with which to counsel their patients and families.
- Copyright © 2014 by the American Academy of Pediatrics