Early Oral Immunotherapy with Pasteurized Egg White in Children Younger than Two Years with IgE-Mediated Egg Allergy: A Prospective Study with Historical Controls

Background: Egg allergy is one of the most common food allergies in early childhood and is traditionally managed through strict avoidance diets, which may negatively affect nutrition and quality of life. Early oral immunotherapy (OIT) may represent an alternative therapeutic strategy; however, controlled studies in children younger than two years remain limited. Methods: We conducted a prospective observational study using historical controls. Thirty-one children younger than two years with IgE-mediated egg allergy underwent OIT using pasteurized liquid egg white (maximum dose: 30 mL; 3300 mg protein). Twelve children managed with an avoidance diet served as the historical control group. Outcomes included desensitization rates, adverse reactions, and longitudinal changes in skin prick test (SPT) wheal diameters, serum-specific IgE (sIgE), specific IgG4 (sIgG4), and sIgE/total IgE ratios. Results: At six months, 29/31 children (93.5%) in the OIT group did not experience allergic reactions after ingestion of any egg preparation, compared with none in the historical control group (p < 0.001). In the control group, 7/12 children (58.3%) continued to react to less-cooked egg preparations, whereas 5/12 (41.7%) remained reactive to all forms of eggs. During the induction phase, 24/31 OIT-treated children (77.4%) experienced mild adverse reactions, predominantly isolated cutaneous or gastrointestinal symptoms, and no patient required intramuscular adrenaline administration. In contrast, allergic reactions occurred in 11/12 controls, including anaphylaxis in 6/12 (50.0%) patients (p = 0.0301). The OIT group demonstrated significant reductions in SPT wheal diameters, sIgE levels, and sIgE/total IgE ratios (all p < 0.001), accompanied by increased sIgG4 levels. Conclusions: Early OIT with pasteurized egg white in children younger than two years with IgE-mediated egg allergy was associated with high desensitization rates, favorable short-term safety outcomes, and significant immunological changes. These findings support the potential role of early active intervention as an alternative to exclusive avoidance strategies in infants with egg allergy.