Long-term outcomes of oral immunotherapy for anaphylactic egg allergy in children

BACKGROUND: Studies of long-term oral immunotherapy (OIT) in children with anaphylactic egg allergy are limited. OBJECTIVE: Our aim was to investigate the long-term outcomes of OIT for anaphylactic egg allergy. METHODS: The participants included children (aged ≥ 5 years) with a history of anaphylaxis in response to eggs and objective reactions to oral food challenge (OFC) with 250 mg of egg protein. In the OIT group, the home starting dose of egg protein set during 5 days of hospitalization was ingested once daily and gradually increased to 1000 mg. Over the next year, participants temporarily discontinued OIT for 2 weeks and underwent OFC with 3100 mg of egg protein annually until they passed. The historical control group comprised patients who did not receive OIT and repeated OFCs annually. RESULTS: In the OIT group (n = 20), the baseline median egg white– and ovomucoid-specific IgE levels were 45.5 and 38.5 kU(A)/L, respectively. The rate of passing OFC with 3100 mg of egg protein gradually increased in the OIT group, with rates of 20% at 1 year, 35% at 2 years, and 55% at 3 years, which were significantly higher than the rates in the historical control group at 3 years (5% [P < .001]). In the OIT group, 5 anaphylaxis events (0.04%) occurred at home, and 1 participant required intramuscular adrenaline. Furthermore, egg white- and ovomucoid-specific IgE levels decreased significantly after 3 years in both groups, whereas in the OIT group, these specific IgG and IgG(4) levels increased significantly after a year. CONCLUSION: Long-term OIT accelerated immunologic changes and enabled ingestion of 3100 mg of egg protein in half of the participants with anaphylactic egg allergy.