Time-limited Specific Oral Tolerance Induction in Children With Severe Egg Allergy

Specific Oral Tolerance Induction in Children With Severe Egg Allergy: A Randomized Controlled Trial Using a 6 Months Protocol

To evaluate the efficacy of a 6-month specific oral tolerance induction (SOTI) protocol in inducing tolerance (maximal dose of raw egg emulsion tolerated) in children with severe IgE-mediated egg allergy and a history of at least 1 anaphylactic reaction after accidental exposure to egg.

Oral immunotherapy consisted in the administration of increasing amounts of raw emulsion egg. The children started with 1 drop of undiluted raw egg emulsion (0.05 ml) flavored with vanilla and cacao, hidden by the parents in the child's breakfast (cow's milk, soymilk, fruit juice or other). The dose was doubled at intervals of about one month in the day hospital. The increases in dose were customized for each subject based on the frequency and severity of side effects, or when an inter-current illness or asthma worsening intervened during the SOTI.

The investigators limited the SOTI protocol to six months for all patients, irrespective of the dose reached, in order to favor the adherence of families to the study.

When objective symptoms seemed more important (grade 2, 3 and 4 reaction), medical treatment was given. Subjects were discontinued from the study in case of severe adverse reactions (grade 5 reaction). Parents were advised they could telephone investigators 24 hours a day

Inclusion Criteria:

• at least 1 anaphylactic reaction (grade 3, 4 and 5 according to Sampson's grading after accidental exposure to trace amounts of egg or egg-derivative products, requiring emergency treatment, at least 1 year before enrollment
• demonstration of egg white specific IgE by the skin prick test (SPT), end-point SPT, raw egg white prick-by-prick (PP) and egg white-specific IgE determination
• positive double-blind placebo-controlled food challenge (DBPCFC) at a dose of less than 0.9 ml of raw emulsion egg

Exclusion Criteria:

• age below 5 years
• poorly controlled asthma
• parents with a history of unreliable management of complications and treatment.