Egg allergy is the second most common food allergy in children. Persistent food allergy increases the risk of anaphylaxis and reduces the quality of life.
To determine the efficacy of oral immunotherapy (OIT) with raw egg white powder and study its effects on humoral responses in children with persistent egg allergy.
Fifty children aged 6-17 years with egg allergy, diagnosed by double-blind, placebo-controlled food challenge, were randomized 3:2 to 8 months of OIT with a maintenance dose of 1 g of egg white protein or 6 months of avoidance after which the avoidance group crossed over to OIT. We examined changes in IgE, IgG4, and IgA concentrations to Gal d 1-4 during OIT compared to avoidance and assessed clinical reactivity at 8 and 18 months.
After 8 months, 22/50 children (44%) on OIT and 1/21 (4.8%) on egg avoidance were desensitized to the target dose, 23/50 (46%) were partially desensitized (dose < 1 g), and 5/50 (10%) discontinued. IgG4 concentrations to Gal d 1-4 and IgA to Gal d 1-2 increased significantly, while IgE to Gal d 2 decreased. A heatmap analysis of the IgE patterns revealed three distinct clusters linked with the clinical outcome. High baseline egg white-specific IgE (EW-IgE) and polysensitization to Gal d 1-4 related with failure to achieve the maintenance dose at 8 months. After 18 months of treatment, 36/50 patients (72%) were desensitized and 8/50 (16%) partially desensitized.
OIT with raw egg enables liberation of egg products into the daily diet in most patients. Subjects with high EW-IgE concentrations and sensitization to multiple egg allergen components at baseline benefit from prolonged treatment.