Special consideration is required for the component-resolved diagnosis of egg allergy in infants.

Abstract Background There are few reports regarding differences in reactivity to the major egg allergens according to children's age, although component-resolved diagnosis is gradually being used. Objective To investigate differences in reactivity to major egg allergens among various age groups of children with egg allergy. Methods Twenty-seven patients diagnosed with egg allergy were included. Egg allergy was defined as a convincing history of reproducible symptoms within 2 hours of egg consumption and an egg white–specific IgE level of at least 0.35 kU A /L. Patients were divided into 3 age groups: younger than 12 months (group A, 7 subjects), 12 to 23 months (group B, 8 subjects), and at least 24 months (group C, 12 subjects). Immunoblotting and enzyme-linked immunosorbent assay investigated IgE reactivity toward ovalbumin, ovomucoid, and ovotransferrin in eggs. Results Immunoblotting analysis showed that all patients in group A reacted to ovalbumin, whereas reactions to other proteins were not detected. All patients in group B displayed a reaction to ovalbumin and ovomucoid. IgE binding to ovotransferrin was shown in 3 patients in group B. All patients in group C displayed reactivity to ovalbumin, 5 patients showed a reaction to ovomucoid, and 8 patients displayed a reaction to ovotransferrin. As a patient's age increased, specific IgE binding to ovalbumin and ovotransferrin increased ( P  = .011 and .004). Conclusion IgE reactivity to egg allergens differs according to children's ages.