Are eggs a cause of food allergy?
Some foods are more liable than others to cause allergic reactions in susceptible people because of the kind of proteins they contain. Eggs contain proteins that, especially in the raw state, may cause allergies in sensitive people. Heating changes the nature of these proteins. This explains why people with a mild allergy to eggs may tolerate some cooked foods, such as cakes or egg pasta, even when they contain relatively large quantities of egg.
Who is most likely to have an egg allergy?
Egg allergy is most common in infants under the age of twelve months and then becomes progressively less of a problem. It is estimated that it affects between 0.5% - 2.5% of infants1, 2 and that most children who have an egg allergy will be able to tolerate eggs by the age of six. By the teenage years it is estimated that only around 30% of them remain egg allergic. In some cases the egg allergy may persist into adult life but a recent analysis found that only 0.5% of young adults in the UK are sensitive to eggs3. Those with other allergies, or with a family history of allergy, seem to be particularly vulnerable.
Can egg allergy in babies be prevented or reduced?
Emerging research shows that eating eggs when pregnant and introducing them when weaning may help reduce the chances of a baby being allergic to eggs in early life.
The latest advice from health experts is that it’s important not to delay the introduction of eggs to your baby’s diet, as this may help reduce the chances of developing an egg allergy later on. Research has shown that delaying the introduction of eggs and peanuts beyond 6-12 months may increase the risk of developing an allergy to these foods.
Read more about this research in the Journal of Health Visiting here.
For more information on feeding eggs to babies, including food safety advice, read about the advice on eggs for mums and babies.
How to recognise egg allergy
In babies, egg allergy usually manifests initially as eczema. Some susceptible babies, from families with a history of allergy, may be sensitised to egg allergens very early in life, when the baby is in the womb. Later, the presentation of an egg allergy, when a sensitised baby first eats egg, can be quite obvious. Most commonly it starts as a red rash around the mouth, within seconds of eating egg, followed in a few minutes by swelling around the mouth, on the face, and also inside the mouth. Some babies develop vomiting and, occasionally, loose stools. As they get older, children may develop respiratory symptoms such as wheezing, sneezing, or runny eyes. In some there may be a delayed response to eating eggs, with worsening of eczema or more chronic bowel symptoms with tummy swelling, pain, and either constipation or diarrhoea, and failure to gain weight.
Most allergic reactions are mild, but in a few children egg allergy can cause anaphylaxis (total collapse) although this is much rarer than in babies with milk or nut allergies. Egg allergy can also develop in adult life, although this is uncommon. The symptoms in an adult can be similar to those seen in childhood, but particularly include skin swellings or eczema and asthma, which can develop more gradually.
Does egg allergy last forever?
Although there are some food allergies that tend to be life-long - such as allergy to peanuts - egg allergy is not usually one of them. By the age of six or seven, many egg-allergic children can eat eggs and the emergence of an egg allergy after this age is uncommon. An analysis4 found that only 0.5% of young adults in the UK are sensitive to eggs.
What should I do if I think my child may have an egg allergy?
You should ask your GP for advice and a proper diagnosis. Eggs may be present in cakes, custard, mayonnaise and some pasta, as well as in some breads, in the glazes on buns or pies, and in some confectionery, so if all egg-containing foods are to be avoided by your child, you will need the help of a registered dietitian. It is advisable to keep a record of any occasions when an egg-containing food is eaten by mistake and of any symptoms that may follow, so that a judgment can be made as to whether the symptoms are diminishing.
Further details on Egg Safety
1 Rona RJ, Keil T, Summers C et al (2007) The prevalence of food allergy: A meta-analysis. Journal of Allergy and Clinical Immunology, 120:638-46
2 Xepapadaki et al. (2016) Incidence and natural history of hen's egg allergy in the first 2 years of life-the EuroPrevall birth cohort study. Allergy. 2016 Mar;71(3):350-7.
3 Savage JH, Matsui EC, Skripak JM et al (2007) The natural history of egg allergy, Journal of Allergy and Clinical Immunology, 120:1413-7
4 Burney P, Summers C, Chinn S, Hooper R, van Ree R, Lidholm J, Prevalence and distribution of sensitization to foods in the European Community Respiratory Health Survey: a EuroPrevall analysis, European Journal of Allergy and Clinical Immunology, 10:1111, p.1398-9995