Frequent Baked Egg Ingestion Was Not Associated With Change in Rate of Decline in Egg Skin-Prick Test in Children With Challenge-Confirmed Egg Allergy

Abstract

To determine if the natural history of egg allergy would be altered by the frequent ingestion of baked egg in food challenge–confirmed egg-allergic children.A retrospective clinical cohort study of 125 children from the Department of Allergy and Immunology, Royal Children’s Hospital, Victoria, Australia, was completed. Participants from 1996 to 2005 with challenge-proven egg allergy were included, providing they had at least 2 egg skin-prick tests performed within this period.A telephone questionnaire was conducted to assess the frequency of baked egg ingestion as follows: (1) frequent (more than once per week), (2) regular (more than once every 3 months, up to once per week or less), or (3) strict avoidance (once every 3 months or less). A multiple linear regression analysis, adjusting for possible confounders, was used to examine the relationship between frequency of baked egg ingestion and the rate of decline in egg skin-prick test size.The mean rate of decline in egg skin-prick test size in all children was 0.7 mm per year (95% confidence interval [CI] 0.5–1.0 mm per year). The frequency of baked egg ingestion did not affect the rate of decline in egg skin-prick test size (P = .57). Individual results for each group were as follows: frequent ingestion (n = 21, mean 0.4 mm per year, 95% CI 0.3–1.2 mm per year), regular ingestion (n = 37, mean 0.9 mm per year, 95% CI 0.4–1.4 mm per year), and strict avoidance (n = 67, mean 0.7 mm per year, 95% CI 0.4–1.1 mm per year).Frequent baked egg ingestion was not associated with a different rate of decline in egg skin-prick test compared with strict avoidance in egg-allergic children.This study is different from previous studies from the Mount Sinai, New York, group (J Allergy Clin Immunol. 2008;122;977–983; J Allergy Clin Immunol. 2012;130(2):473–480) who have shown that regular ingestion of heated egg (defined as 1–3 servings per day) was associated with decreased skin-prick test wheal diameters to egg white and decreasing egg white, ovalbumin, and ovomucoid-specific immunoglobulin E antibody levels. This study does not specify the frequency of baked egg ingestion in the more than once a week group. It appears that this dosing interval may be critical to make the most impact immunologically. Clearly, ingestion once every 3 months or strict avoidance of egg does not appear to accelerate the development of egg tolerance.