Egg Allergy in Children: Everything Parents Need to Know

What causes egg allergy?

Egg allergy is caused by an immune reaction to proteins in egg white — primarily ovalbumin, ovomucoid (Gal d 1), and ovotransferrin. Ovomucoid is the most heat-stable protein, meaning it survives cooking and is associated with more persistent allergy. Children with high levels of ovomucoid-specific IgE are less likely to tolerate baked egg and less likely to outgrow their allergy quickly. Egg yolk allergy is less common.

Symptoms of egg allergy

• Hives (urticaria) — raised, itchy welts on the skin, typically within minutes of egg exposure
• Redness or swelling around the mouth
• Swelling of the lips, tongue, or face
• Vomiting or nausea
• Stomach cramps or diarrhoea
• Runny nose, sneezing, or watery eyes
• Worsening eczema following egg ingestion
• Wheezing or difficulty breathing
• Anaphylaxis — in severe cases

Baked egg tolerance — a key concept

One of the most important features of egg allergy is that many children can tolerate well-baked egg (e.g. in cakes, biscuits, and bread) even when they react to lightly cooked or raw egg. This is because the high heat of baking denatures (changes the structure of) the egg proteins, making them less recognisable to the immune system. Children who tolerate baked egg are encouraged to eat it regularly, as this actively promotes the development of tolerance to less processed egg forms.

How egg allergy is diagnosed

Diagnosis involves a detailed clinical history, skin prick testing, and specific IgE blood tests. Component-resolved diagnostics — particularly ovomucoid (Gal d 1) — are highly valuable: high Gal d 1 levels predict that the child is unlikely to tolerate baked egg and that the allergy is likely to persist. A supervised baked egg challenge in clinic can confirm whether your child can safely eat baked egg products.

The egg ladder — a structured reintroduction protocol

The egg ladder is a stepwise protocol for gradually reintroducing egg in progressively less processed forms. It typically starts with well-baked egg in cakes and biscuits, then moves through scrambled egg, omelette, and finally raw egg (e.g. in mayonnaise or lightly cooked dishes). Each step is only attempted once the previous step has been tolerated for a period of time. The ladder should be followed under specialist guidance.

Will my child outgrow egg allergy?

Yes — the majority of children with egg allergy outgrow it by school age. Studies suggest that around 70% of children are tolerant of egg by age 7. Children who tolerate baked egg tend to outgrow their allergy faster. Ovomucoid (Gal d 1) levels on component testing can help predict the likelihood and timing of outgrowing the allergy.

Egg allergy and the MMR vaccine

Parents often worry about the MMR vaccine in children with egg allergy. Current UK guidelines confirm that the MMR vaccine is safe for all children with egg allergy, including those with a history of anaphylaxis to egg. The MMR vaccine is not grown in egg and does not contain significant egg protein. The flu vaccine may require specialist advice for children with severe egg allergy.

Managing egg allergy day-to-day

• Strict avoidance of egg and egg-containing products for children who react to baked egg
• Regular inclusion of baked egg for children who tolerate it — this promotes tolerance development
• Careful label reading — egg is a major allergen and must be declared on food labels
• Written emergency action plan and adrenaline auto-injector for children at risk of anaphylaxis
• School and nursery allergy management plan
• Annual specialist review to reassess allergy status and progress through the egg ladder