Egg Allergy Treatment for Children

Egg Allergy

Hen’s egg allergy is the second most common food allergy in infants and young children (cow's milk is the most common). Egg allergy occurs due to immunologic responses to proteins in egg and include immunoglobulin IgE antibody mediated as well as other non-IgE allergy presentations such as eczema and eosinophilic oesophagitis.

Egg allergy affects up to 2.5% of young children. Most children outgrow egg allergy in childhood.

Five major allergenic proteins from the egg have been identified responsible for IgE mediated reactions, these are designated Gal d 1 to 5, ovomucoid (Gal d 1), ovalbumin (Gal d 2), ovotransferrin (Gal d 3), lysozyme (Gal d 4) and ovomucin. Most of the allergenic proteins are found in egg white.

Majority of egg allergic individuals can tolerate extensively heated baked egg. Heating denatures proteins. Heating may reduce allergenicity of ovalbumin by altering digestion and absorption of these proteins in the gastrointestinal tract. Ovalbumin is heat labile, but ovomucoid protein is not altered by extensive heating. This suggests that children who have IgE primarily to ovalbumin are likely to tolerate heated forms of egg.

IgE mediated reactions are the most common type of allergic reactions to hen’s egg and usually occur immediately, within minutes to 2 hours after ingestion. Symptoms such as
urticaria, angioedema, respiratory symptoms and laryngeal oedema are common. Reactions can vary from mild to life-threatening anaphylaxis.

Non-IgE mediated reactions have a delayed onset of action. These are atopic dermatitis (eczema), gastrointestinal reactions including eosinophilic oesophagitis and food protein
induced enterocolitis syndrome FPIES.
Tolerance is achieved by majority of the children with egg allergy.

Diagnosis: Clinical history supported by the following tests. Assessments should be undertaken every 6-12 months.
IgE mediated allergy
Skin Prick Test
Blood test- Total IgE and IgE to egg white and yolk
Component egg protein test – Gal d1 to 4

Non IgE mediated allergy
Egg exclusion for 2 weeks, followed by 2 weeks of egg inclusion to confirm
These tests provide an indication of likelihood of clinical reactivity to egg but are not able to predict the severity of allergic reactions that may occur with each individual or the natural history of the аllеrgy. The rate of decline of specific IgE levels over time is a prognostic indicator for the development of tolerance.

Management:
Avoidance of egg and egg containing products

Evaluation of allergy followed by an oral challenge to extensively heated egg e.g. cake,
muffin
Egg ladder
MMR immunisation is not contraindicated in egg allergy