Egg allergy: is egg allergy common?

 

Have you already eaten egg today? The probability is relatively high. Eggs are not only a staple ingredient in many cooking and baking recipes. They are also found in countless packaged foods, sauces, baked goods and much more. This is what makes it so difficult for people with an egg allergy to avoid the trigger of their allergy. 

Egg allergy is relatively widespread, especially among children. If you have been diagnosed with an egg allergy, you should not only skip eggs with your full English breakfast; you need to also study ingredient lists. This is because eggs are unfortunately also found in many packaged foods and ready-made products.

Read this article to find out what happens in the body when you have an egg allergy, what an allergic reaction to eggs may look like, and how to find out if you are affected by this allergy. We also provide you with some dietary tips in case you can no longer eat eggs.

What is an egg allergy?

Egg allergy is one of the most common food allergies, occurring in people all over the world. Babies and children under the age of five are particularly often affected. 

If you have an allergy, your immune system reacts to certain proteins found in chicken egg, especially the egg white. The body produces too many IgE antibodies. These antibodies trigger an exaggerated defensive reaction when the egg allergens enter the body. This then leads to the typical food allergy symptoms, such as skin rashes and gastrointestinal issues.^{[1, 2]}

It used to be said that eggs were bad for your cholesterol levels. Today, we know that eggs contain mainly the healthy HDL cholesterol and can therefore even have a positive effect on your cholesterol.^[3]

Egg allergy versus egg intolerance

When you suffer from a food intolerance, something different happens in your body. Often, something is wrong with the way your intestines process certain foods. While with a food allergy, it is your immune system reacting to a certain allergen, a food intolerance consists of a non-immunological reaction to certain foods.

An egg intolerance would therefore trigger different symptoms than an egg allergy, including flatulence, nausea, constipation, diarrhoea and vomiting.

To read more about the differences between a food allergy and food intolerance, head over to our Health Portal article.

What triggers an allergic reaction to eggs?

Substances that can trigger allergies in people are called allergens. These are almost always certain proteins that are found in pollen and food, for example. With an egg allergy, your body usually reacts to one or more of the following four proteins:

• Ovomucoid
• Ovotransferin
• Ovalbumin
• Lysozyme

Ovomucoid is a heat-resistant protein found in egg whites. This means that high temperatures cannot destroy it. The allergen therefore still remains in cooked and processed eggs and can thus still trigger an allergic reaction to eggs. The other typical egg allergens break down when exposed to heat, so they are only problematic when the egg is still raw.^{[1, 2]}

Lysozyme is an enzyme that can render the cell walls of certain bacteria harmless. It is not only found in egg white, but also in the tear fluid and saliva of humans. Food manufacturers use lysozyme as a preservative to protect food from bacteria.

In general, many people with egg allergies have no or only mild egg allergy symptoms with baked foods that contain eggs, such as cakes and muffins. According to a study, this is true for 65 to 81 per cent of egg allergy sufferers. As an allergy sufferer, however, you should definitely not try this without medical supervision.^[4]

Was causes egg allergy?

At the moment, scientists are still trying to understand how and why allergies develop. In any case, genes play a role. For example, children whose parents both have egg allergies have a higher risk of developing one.^[5]

If children are born with atopic dermatitis, they are also more likely to develop an allergy. Neurodermatitis, allergies and asthma often occur together and can influence each other. Doctors therefore classify the three diseases as atopic.^[6]

Is egg allergy common?

In Europe, according to the European Centre for Allergy Research Foundation, egg allergy has been found in 0.2 per cent of the population – the proportion of people who suspect they have an allergy is much higher at 2.5 per cent.^[1] Egg allergy is most common in children under the age of five. According to some studies, up to two per cent of children of this age are affected worldwide.^{[2, 4]}

Besides egg allergy, other common food allergies in the United Kingdom include milk allergy, nut allergy, fish allergy and shellfish allergy. You can usually take tests to screen for specific food allergies, like those mentioned above, or you can take food allergy tests, which screen for several food allergies at once. These tests work by analysing the IgE antibody concentration in your blood to up to 40 different foods.

Egg allergy in infants: is it widespread?

In most cases, children develop an egg allergy very early on, before they reach two years of age. It often disappears by itself over the course of childhood. According to one study, 37 per cent of the children affected by egg allergy will no longer experience an allergic reaction to eggs by the age of 10, and 68 per cent by the age of 16.^[7]

Researchers also found some evidence regarding which children found that their allergies disappeared and which did not. Apparently, allergies often remained in children who had particularly high levels of IgE antibodies to the allergens in their blood.^{[4, 7]}

What about egg allergy in adults?

It is very unlikely that you will develop an egg allergy in adulthood. However, some adults develop what is called bird-egg syndrome. These people are initially allergic to feathers and bird droppings.

Over time, they also develop a reaction to chicken eggs, especially the yolk, and sometimes also to chicken meat. This is due to serum albumin, a group of proteins found in both egg yolks and the meat and feathers of birds. However, these allergens are not heat-resistant.

Since chicken meat and eggs are usually cooked, they therefore rarely cause symptoms. What is more common with bird-egg syndrome is that skin contact with raw chicken meat leads to an allergic reaction.^{[1, 8]}

Cross reactivity: can egg allergy contribute to other allergies?

As with other allergies, an egg allergy can trigger cross-reactions. This happens whenever one allergen is similar to another in food or pollen, for example, and the body therefore reacts to both allergens.

An egg allergy can trigger cross-reactivity with the eggs of other animals, such as duck, quail and goose.^[4] Children who have an egg allergy are also at a higher risk of developing a peanut allergy, according to studies.^[9]

If you suspect that you might be allergic to other foods, due to food allergy symptoms, you can always take a food intolerance test and food allergy test to be on the safe side. For information, read our article on cross-reactivity in our Health Portal.

What are typical egg allergy symptoms?

Egg allergy is an allergy where the reaction happens immediately. This means that an allergic reaction to eggs occurs directly or shortly after you have eaten an egg. Symptoms can affect the gastrointestinal tract, but also the skin and the respiratory tract. Typical symptoms include

• burning in the mouth area;
• nausea, vomiting, abdominal pain, diarrhoea;
• hives; and
• respiratory problems.

Chicken eggs are also one of the foods that can cause severe allergic reactions. Studies show that up to 12 per cent of all anaphylactic shocks in children are due to an egg allergy.^[4] Anaphylaxis involves symptoms such as shortness of breath, palpitations, circulatory problems and dizziness and even unconsciousness. It can be fatal, but this is very rare with an allergic reaction to eggs.^{[1, 10]}

Is there a test for egg allergies?

If you suspect you have an egg allergy, there are several ways to check. Typical allergy-testing methods include a skin prick test and blood tests that screen for specific IgE antibodies. An egg allergy test can show that you are sensitised to eggs, meaning only that your immune system produces an increased number of antibodies against egg allergens. Doctors only diagnose an allergy if typical allergy symptoms are also present. 

A provocation test can provide even more clarity. Under medical supervision, you are given the allergen. Doctors then check whether you have an allergic reaction to eggs.^[17]

How can I test for egg allergies?

Prick tests, blood tests and provocation tests can usually be done at your doctor’s surgery. However, there are home health tests you can order online, for which you need only take a sample at home and send it to a laboratory. The laboratory then sends you your test results within a few days.

Egg allergy treatment: can egg allergy go away?

If you suffer from an egg allergy, the best egg allergy treatment is to completely eliminate eggs and products containing eggs from your diet. Eggs are hidden in many ready-made products, for example

• puddings, chocolate bars and other sweets;
• soups, sauces, salad dressings and mayonnaise;
• baked goods; and
• meat products and battered dishes.

So, you should always study the ingredient lists of packaged foods and ask about allergens in restaurants and bakeries.^[10]

If your child suffers from an egg allergy, you should also avoid these foods as a breastfeeding mother. This is because allergens can be passed on to your baby through breast milk.

How do I look for egg on packaging labels?

Food manufacturers in the United Kingdom now have to highlight certain allergens on the packaging of their products. Egg and egg products are among them. Restaurants and market stalls are also obliged to provide customers with information about the most common allergens, and thus also about eggs.^[12]

The statement ‘May contain traces of egg’ is voluntary. Theoretically, therefore, minor traces of the allergens can also be found in these packaged foods.^[13]

How do I replace eggs in cooking and baking?

Eggs feature in many baking and cooking recipes – mostly not because of their taste, but because they cause other ingredients to bind together. For allergy sufferers, however, there are various ways to replace eggs in recipes. Apple pulp, bananas, flaxseed and soy are all possible alternatives, depending on the dish. When it comes to the colour and taste of egg, spices such as black salt (kala namak) and turmeric can help.

Tip: If you have an egg allergy, you might be interested in reading more about the benefits of a vegan diet, as vegans, too, must refrain from eating eggs. Whether you find ideas for supplements or recipes, veganism could inspire you to live a healthy life without eggs!

What about egg in medicines and vaccines?

Medicines sometimes also contain eggs. For example, flu viruses are grown in chicken eggs to produce some flu vaccines. Therefore, the vaccines may contain small amounts of egg.^[14] 

Studies have shown that the vaccines to prevent the flu or cold are safe even for people with severe allergies and anaphylaxis. However, you should always tell your doctor about your allergy when you get a flu shot. Doctors can then choose a well-tolerated vaccine or monitor you after vaccination in case an allergic reaction occurs.^{[15, 16]}

In terms of the Covid-19 vaccines that are currently being rolled out on a large scale worldwide, egg allergy sufferers will be relieved to hear that there are no traces of egg proteins found in the Pfizer/BioNTech, AstraZeneca, Johnson & Johnson or Moderna Covid-19 vaccine.

Egg allergy treatment: is there any medication for an egg allergy?

There is currently no cure for egg allergy. However, you can reduce egg allergy symptoms with medication – antihistamines tablets are suitable for this. If you have already suffered an anaphylactic shock, your doctor will prescribe you an anaphylaxis emergency kit that you can use in case of another shock. The kit includes, among other things, an EpiPen that you can use to inject adrenaline into your thigh in an emergency.^[1]

Will I miss out on nutrients if I can’t eat egg?

As a great source of protein, eggs provide our bodies with many crucial nutrients, including zinc, vitamin D, vitamin B12, riboflavin and calcium.^[18]

If you are concerned that you may be deficient in minerals or vitamins as a result of omitting egg from your diet, it may be wise to regularly check your levels with a diagnostic test. Like the allergy tests, these can be either done at your doctor’s surgery or at home with a at-home test kit.

It is vital that, if you are diagnosed with a deficiency, such as a vitamin D deficiency or a vitamin B12 deficiency, that you discuss with your doctor how to optimise your nutrient intake – whether this is through a change in diet or through taking various dietary supplements.

Egg allergy – at a glance

What is an egg allergy?

An egg allergy is one of the most common food allergies, especially for babies and children – it often disappears by adulthood. Those affected mostly react to different proteins found in egg whites and yolks.

What are typical egg allergy symptoms?

Egg allergy symptoms are symptoms that can affect the gastrointestinal tract (diarrhoea, abdominal pain), the skin (redness, swelling, itching) and the respiratory tract (sneezing, coughing, shortness of breath). An egg allergy sufferer can also experience anaphylactic shock, the most severe allergic reaction.

Is there a test for egg allergies?

With a skin prick test or a blood test, you can determine whether your immune system produces too many antibodies against the allergens found in egg. If this is the case, you are sensitised to egg. If you have additional symptoms after eating eggs – that is, an allergic reaction to eggs – it is very likely that you have an egg allergy.

What can I do if I have an egg allergy?

There is currently no cure for an egg allergy. If you are allergic to eggs, the only thing that helps is to stop eating them. Be aware of egg products hidden in packaged foods, baked goods, sauces and other foods. Read ingredient lists carefully and ask for allergens in restaurants and at the bakery.

Sources

^[1]        European Centre for Allergy Research Foundation, ‘Hühnereiallergie’, ECARF, available at http://www.ecarf.org/info-portal/allergien/huehnereiallergie/, accessed on 13 March 2018.

^[2]        Urisu, A., Kondo, Y, Tsuge, I. ‘Hen’s Egg Allergy’, Chem Immunol Allergy, vol. 101, pp. 124–130, 2015, doi: 10.1159/000375416.

^[3]        Bundeszentrum für Ernährung, ‘Cholesterin: Mythos Frühstücksei: Fettbewusst essen – worauf es ankommt!’, available at https://www.bzfe.de/inhalt/erhoehte-blutfettwerte-ein-risiko-fuer-herz-und-kreislauf-2026.html, accessed on 14 March 2018.

^[4]        Tan, J. W., P. Joshi, P. ‘Egg allergy: An update’, J Paediatr Child Health, vol. 50(1), pp. 11–15, Jan. 2014, doi: 10.1111/jpc.12408.

^[5]        Bundeszentrum für Ernährung, ‘Allergie gegen Ei, Milch und Nüsse: Welchen Einfluss haben die Gene?’, 8 March 2018, available at https://www.bzfe.de/inhalt/allergie-gegen-ei-milch-und-nuesse-31404.html, accessed on 8 March 2018.

^[6]        American College of Allergy, Asthma & Immunology, ‘Egg Allergies in Children and Adults: Symptoms and Alternatives’, Healthline, 4 May  2012, available at https://www.healthline.com/health/allergies/egg, accessed on 14 March 2018.

^[7]        Savage, J. H. et al., ‘The natural history of egg allergy’, Journal of Allergy and Clinical Immunology, vol. 120(6), 2007.

^[8]        Hemmer, W., Klug, C., Swoboda, I. ‘Vogel-Ei-Syndrom und genuine Hühnerfleischallergie’, Allergo J, vol. 25(3), pp. 22–29, May 2016, doi: 10.1007/s15007-016-1073-2.

^[9]        Du Toit, G. et al., ‘Identifying infants at high risk of peanut allergy: the Learning Early About Peanut Allergy (LEAP) screening study. - PubMed’, Journal of Allergy and Clinical Immunology, vol. 131(1), 2013.

^[10]      American College of Allergy, Asthma & Immunology, ‘Egg Allergy’, ACAAI Public Website, 12 January 2015, available at https://acaai.org/allergies/types/food-allergies/types-food-allergy/egg-allergy, 13 March 2018.

^[11]      Bundeszentrum für Ernährung, ‘Eier: Gesund essen: Was macht Eier so wertvoll?’ available at https://www.bzfe.de/inhalt/eier-gesund-essen-4168.html, accessed on 13 March 2018.

^[12]      Deutscher Allergie- und Asthmabund, ‘Hühnerei-Allergie: DAAB’, 8 March 2018, available at http://www.daab.de/ernaehrung/huehnerei-allergie/, accessed on 8 March 2018.

^[13]      Bundesministerium für Ernährung und Landwirtschaft, ‘Lebensmittel-Kennzeichnung’, available at https://www.bmel.de/DE/Ernaehrung/Kennzeichnung/kennzeichnung_node.html, accessed on 9 October 2019.

^[14]      CDC, ‘Flu Vaccine and People with Egg Allergies’, Centers for Disease Control and Prevention, 28 December 2017, available at https://www.cdc.gov/flu/protect/vaccine/egg-allergies.htm, accessed on 14 March 2018.

^[15]      Balakireva, A. V., Zamyatnin, A. A. ‘Properties of Gluten Intolerance: Gluten Structure, Evolution, Pathogenicity and Detoxification Capabilities’, Nutrients, vol. 8(10), October 2016, doi: 10.3390/nu8100644.

^[16]      Greenhawt, M. J. et al. ‘Safe administration of the seasonal trivalent influenza vaccine to children with severe egg allergy’, Ann. Allergy Asthma Immunol., vol. 109(6), pp. 426–430, December 2012, doi: 10.1016/j.anai.2012.09.011.

^[17]      Worm, M. et al. ‘Guidelines on the management of IgE-mediated food allergies’, Allergo J Int, vol. 24, pp. 256–293, 2015, doi: 10.1007/s40629-015-0074-0.

^[18]      Drewnowski, A. ‘The Nutrient Rich Foods Index helps to identify healthy, affordable foods’, Am. J. Clin. Nutr. 2010;91:1095s–1101s. doi: 10.3945/ajcn.2010.28450D. 

^[19]      ‘Covid-19 Vaccines and Allergies’, Anaphylaxis Campaign, available at https://www.anaphylaxis.org.uk/covid-19-advice/pfizer-covid-19-vaccine-and-allergies/#:~:text=Do%20the%20COVID%2D19%20vaccines,are%20contraindicated%20in%20egg%20allergy, accessed on 4 June 2021.