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

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.