Abstract
BACKGROUND: Egg allergy is a common IgE-mediated food allergy in children. Oral immunotherapy (OIT) reduces allergic reactions via gradual allergen exposure. Although high maintenance doses (1-6 g egg protein) are often used, they carry higher risks of adverse reactions. Evidence on the safety and effectiveness of lower-dose egg OIT (E-OIT) remains limited. OBJECTIVE: We sought to determine whether a low dose of 300 mg E-OIT is safe and effective for desensitization. METHODS: Twenty-two participants were recruited from the Montreal Children's Hospital; 20 were randomized to an immediate-treatment group or an observation group (egg avoidance for 1 year before OIT). Cumulative tolerated dose (CTD), Gal d 1- and Gal d 2-specific IgE (sIgE) and -specific IgG4 (sIgG4), and skin prick test responses were measured at baseline, postescalation, and maintenance. Adverse events were recorded throughout the study. RESULTS: At baseline, CTD did not differ between groups (treatment: median, 14.1 mg; observation: 20.1 mg; P = 1). After 1 year of egg avoidance, CTD in the observation group remained low (32.3 mg; P = .06). Following E-OIT, the treatment group showed a significant increase in CTD to 2000 mg at postescalation (P = .004) and 6000 mg at the exit double-blind, placebo-controlled food challenge (P = .009). The observation group, after crossover, reached 1000 mg postescalation (P = .02) and 5000 mg at exit (P = .04). Adverse reactions occurred in 15.6% of 5971 doses, mostly mild. Skin prick test wheal diameters decreased significantly (P < .001); s-IgE levels declined whereas s-IgG4 levels increased (P < .001), and sIgG4/sIgE ratios improved. No significant clinical or immunologic changes occurred during the observation period. CONCLUSIONS: Targeting a low maintenance dose of 300 mg E-OIT produces significant clinical and immunologic changes in individuals with egg allergy while maintaining low risk of adverse reactions.