Hen's Egg Allergy: Immunological Mechanisms, Epidemiology, and Predictors of Persistence in Childhood

Hen's egg allergy is one of the most common food allergies worldwide and has a significant impact on children's health. Hen's egg allergy is primarily immunoglobulin E (IgE)-mediated reaction, and Gal d 1-5 are the most common allergens. Filaggrin mutations impair skin barrier function, promoting sensitization and persistent allergy. Family history, early atopic dermatitis, and limited microbial exposure can increase the risk of egg allergy. Additionally, there is a difference in the prevalence of hen's egg allergy between Eastern and Western countries. Egg allergy is closely linked to moderate-to-severe atopic dermatitis and follows the atopic march, with many children outgrowing it by school age; however, the early or persistent IgE sensitization increases the risk of asthma and rhinitis later in childhood. A high initial IgE level, large skin prick test wheals, multiple food allergy, severe eczema, Gal d 1 sensitization, filaggrin gene mutations, and epigenetic changes can be used to predict the risk of persistent egg allergy. Early introduction of allergenic foods, such as eggs, may safely reduce future allergy risk. Oral, sublingual, and epicutaneous immunotherapies offer desensitization options, but they rarely achieve long-term tolerance and raise safety concerns.