Oral Immunotherapy for Egg Allergy: A Double-Blind Placebo-Controlled Study, with Postdesensitization Follow-Up

Abstract

Background: Oral immunotherapy (OIT) may be an effective treatment for food allergy in children. It is not clear if the OIT-induced effect is achieved by desensitization (transient state dependent on regular antigen exposure), or by tolerance (persistent condition where the ability to consume the food is retained even after a period of withdrawal).

Objective: The aim of this study was to investigate the efficacy of OIT-egg desensitization in a double-blind placebo-controlled study, and to evaluate if, after desensitization, tolerance can be maintained.

Methods: Children with egg allergy were randomized to OIT or placebo for 4 months. At the end of the controlled phase, a double-blind food challenge was repeated to confirm the achieved desensitization. Those subjects found to be desensitized were placed on an egg-containing diet for 6 months, followed by an egg avoidance phase for 3 months, when the food challenge was repeated to determine the maintained tolerance.

Results: A total of 31 children were randomized to OIT with dehydrated egg white (n = 17) or placebo (n = 14). Of the 17 active patients (1 dropout), 16 achieved desensitization and started the 6-month egg-containing diet. After 3-month of egg avoidance, 31% remained tolerant. In the control group, only 1 passed the final food challenge. Egg-specific IgG4 increased only in the active group. Five active OIT patients had side effects.

Conclusion: Egg OIT results in desensitization in almost all subjects, although tolerance was maintained in only 1/3 of them after a 3-month period of withdrawal. Side effects were encountered, but the procedure appeared safe. In hen egg allergy, OIT is effective for desensitization.

Keywords: Dehydrated egg white; Egg allergy; Follow-up; Oral immunotherapy; Tolerance.