Objective: Hen`s egg is one of the most common causes of food allergy worldwide. A hen`s egg ladder is used to accelerate the acquisition of tolerance. This study investigated the frequency of tolerance achieved with the hen`s egg ladder and the factors influencing tolerance.

Materials and Methods: Patients with IgE-mediated hen`s egg allergy younger than five years of age who underwent egg laddering were reviewed.

Results: The study group consisted of 85 patients with a median (min-max) age at diagnosis of 11 months (3-48 months) with a male predominance (61.2%). The most common symptoms, in terms of frequency, were eczema (53%), urticaria (15.2%), angioedema (10.5%) and vomiting (9.4%). Six patients had anaphylaxis. The most common co-allergens were cow`s milk and peanuts. Of the 85 patients, 76 (89.4%) patients tolerated baked whole hen`s eggs, and 9 (10.6%) were allergic to baked hen`s eggs, including 5 to egg yolk and 4 to egg white. The median age at diagnosis was statistically significantly lower and the eosinophil count was significantly higher in the allergic group (p=0.010, p=0.033, respectively). In the study group, 70 (82.4%) were tolerant to whole hen`s eggs and 15 (17.6%) who had a positive OFC at any stage were allergic. The median age at diagnosis and the presence of anaphylaxis were found to be significantly higher in the persistent group (p=0.031 and p=0.008, respectively). Caesarean section was also found to be a factor delaying tolerance in all forms of hen`s egg allergy.

Conclusion: The frequency of tolerance is high in hen`s egg allergy. Tolerance to baked forms develops at an earlier age. The use of an egg ladder that gives priority to egg yolk is thought to induce early tolerance.