Figure 1. Predefined decision tree for food allergy diagnosis in the...

What Is Egg Intolerance?

An egg intolerance is a non-life-threatening adverse response to the consumption of eggs. It typically causes gastrointestinal upset symptoms, such as bloating and diarrhea.

You might have an intolerance to the egg white, yolk, or both.

In some cases, an intolerance can last for years, while some people can have problems with eggs for life. It can also occur at any age.

Talk with a doctor if you think you or your child has a sensitivity to eggs so they can rule out allergies and help offer tips to manage.

An intolerance to eggs means your body adversely reacts to this particular food. It's also possible to have multiple food sensitivities, such as reactions to gluten, dairy, and soy.

An egg intolerance differs from an egg allergy, which is due to an immune reaction to egg proteins.

With an egg allergy, your immune system reacts by attacking substances your body can't tolerate. Right after you eat eggs, you might notice symptoms such as itchy rashes and swelling, especially around your face and throat.

Severe egg allergies can trigger a severe allergic reaction called anaphylaxis, which is a life threatening event that can stop breathing and consciousness.

An egg intolerance doesn't cause allergy symptoms or anaphylaxis. You'll still be able to tell you have a sensitivity to eggs, though, based on the symptoms you experience after eating them.

Some alternative or integrative practitioners may offer food sensitivity tests by looking for antibodies in the blood, but these are controversial and often not covered by insurance.

You may also be able to find a DNA kit online to help detect food sensitivities, but such tests may not be as accurate.

A perhaps more affordable — and accurate — way is to track your symptoms after eating eggs in a food diary. Detail is important here, as food intolerance symptoms aren't always immediate.

You might also want to note how long your symptoms last. After several weeks, your doctor can review this to help determine whether you have a food intolerance.

The most effective egg intolerance treatment is to avoid eggs as much as possible.

Your doctor may recommend an elimination diet, in which you essentially avoid eggs for up to 6 weeks at a time. You may then see how you feel and decide whether you want to gradually add eggs back into your diet.

Aside from whole eggs or egg whites, you'll also want to avoid dishes cooked with eggs. When eating out, ask if any dishes contain eggs to help prevent possible reactions after your meal.

It's also possible for children to grow out of an egg intolerance. Most children also outgrow egg allergies, with an estimated 70% getting over them by age 16.

An egg intolerance doesn't mean you'll develop an egg allergy.

Aside from the symptoms endured after eating eggs, there's also a risk of missing key nutrients that eggs provide. These include:

If you aren't able to have eggs at least a couple of times a week, talk with your doctor about whether you're low in these key nutrients. You may need to incorporate other foods or supplements to prevent nutritional deficiencies.

On the flip side, an egg allergy is much more dangerous. This is why it's important to make sure that you have an egg intolerance and not an allergy, just in case you accidentally consume eggs and egg products.

You can tell the difference between the two by the symptoms. While an allergy can cause diarrhea and other symptoms of stomach upset, an allergic reaction to eggs can also cause breathing difficulties and a drop in blood pressure.

An egg intolerance can be unpleasant, but the most effective way to alleviate symptoms is by practicing an elimination diet. Your reactions to foods can also change over time, especially through adulthood.

Egg allergies, on the other hand, are extremely dangerous, especially in children. Call your doctor if you think your child has a food allergy. Any anaphylactic symptoms require emergency medical care.

Why Some People Have Egg Intolerance: Possible Causes

Eggs are incredibly nutritious. They're a complete source of protein that provides energy to the body, contain choline, which is essential for brain and neurological health, and are rich in vitamin B12, vitamin D, selenium, and iodine. But despite having so many benefits, some people avoid it—not by choice, but simply because they cannot tolerate it. But what is egg intolerance, and is it really a thing? We at OnlyMyHealth inquired all about it from Divya Gopal, Consultant Dietitian and Nutritionist, Motherhood Hospitals, Banashankari, Bengaluru, who also shared how it is different from an egg allergy.

What Is Egg Intolerance?

Gopal described egg intolerance as a condition where the digestive system struggles to process eggs, leading to gastrointestinal symptoms such as stomach pain, bloating, gas, diarrhoea, and nausea.

She said, "These symptoms typically appear a few hours after consuming eggs and are a result of the body's inability to digest certain proteins found in eggs properly."

Also Read: Eggs For Breakfast: Expert Lists Benefits Of Eating Eggs In The Morning

But mind you, egg intolerance and egg allergy are two distinct conditions.

According to the expert, they are both characterised by adverse reactions to eggs, but they differ significantly in their underlying mechanisms, symptoms, and management.

Egg allergy involves the immune system, wherein the body's immune system mistakenly identifies proteins in eggs as harmful and releases histamines and other chemicals in response, explained Gopal.

On the contrary, egg intolerance involves the digestive system, which has difficulty processing proteins in eggs but does not involve the immune system.

Symptoms of egg allergy appear quickly, usually within minutes to a few hours after consuming eggs. These range from mild (hives, nasal congestion) to severe (anaphylaxis, which can be life-threatening and involves difficulty breathing, a drop in blood pressure, and loss of consciousness).

On the other hand, symptoms of egg intolerance typically appear several hours after consuming eggs. These primarily include gastrointestinal symptoms, including bloating, gas, stomach cramps, diarrhoea, and nausea. Other symptoms can include fatigue and headaches.

Possible Causes Of Egg Intolerance

Egg intolerance can occur due to various reasons. According to Gopal, these mainly include:

Enzyme deficiency: Some individuals may lack the necessary enzymes to break down certain proteins in eggs. This can lead to digestive discomfort.

Sensitivity to proteins: Egg whites and yolks contain different proteins that can be hard to digest for some people. Common proteins that cause intolerance include ovomucoid, ovalbumin, ovotransferrin in the egg white, and livetin and apovitillin in the yolk.

Bacterial overgrowth: An imbalance in gut bacteria, known as dysbiosis, might make it harder for the body to digest certain foods, including eggs.

Cross-reactivity: Sometimes, people with sensitivities to other foods or substances may react to eggs due to similar protein structures (cross-reactivity).

Food additives: Eggs processed with certain additives or preservatives might trigger intolerance symptoms in sensitive individuals.

Leaky gut syndrome: Increased intestinal permeability, commonly referred to as leaky gut syndrome, can allow undigested food particles, including egg proteins, to enter the bloodstream, causing an immune response.

Autoimmune conditions: In some autoimmune diseases, the body's immune system may mistakenly target certain proteins found in eggs, leading to intolerance.

Also Read: The Best Way To Eat Your Eggs If You Have High Cholesterol

Protein Alternatives To Egg

For people with egg intolerance or egg allergy, there are various other sources of protein that can benefit their overall health. Here are some options you can explore:

Tofu: Made from soybeans, tofu is a versatile protein source that can be scrambled to mimic eggs. It contains about 10 grams of protein per half-cup serving.

Chickpea flour: Made from ground chickpeas, chickpea flour is rich in protein and can be used to make omelette-like dishes. It contains about 7 grams of protein per 1/4 cup serving.

Lentils: These are a great plant-based protein source and can be used in a variety of dishes. It contains about 18 grams of protein per cup cooked.

Quinoa: A complete protein source, quinoa contains all nine essential amino acids and has about 8 grams of protein per cup cooked.

Greek yoghurt: Greek yoghurt is a dairy product that contains about 10 grams of protein per 100 grams.

Chia seeds: These seeds are high in protein and omega-3 fatty acids.

According to Dubey, these alternatives not only provide good amounts of protein but also come with additional health benefits, making them excellent options for replacing eggs in various recipes.

It is important to understand that a balanced diet is key, and therefore, if you are unable to or cannot consume eggs, look for other healthy alternatives.

Disclaimer

All possible measures have been taken to ensure accuracy, reliability, timeliness and authenticity of the information; however Onlymyhealth.Com does not take any liability for the same. Using any information provided by the website is solely at the viewers' discretion. In case of any medical exigencies/ persistent health issues, we advise you to seek a qualified medical practitioner before putting to use any advice/tips given by our team or any third party in form of answers/comments on the above mentioned website.

What Is A Food Allergy? Symptoms, Causes And Treatment

Last Updated : 28 May 2025

Table of contents

Food allergies involve an immune system response to proteins in foods, leading to symptoms such as itchy eyes, shortness of breath, dry mouth, skin redness and hives, abdominal pain, nausea, vomiting, diarrhoea, and in severe cases swelling of the airways and a drop in blood pressure (anaphylaxis).

Food allergies are most common in children and prevalence decreases with age. Some allergies, such as those to peanuts or tree nuts, are more likely to persist into adulthood.

There is currently no cure for food allergies. To manage a food allergy, people who are allergic must completely avoid the allergen to avoid adverse reactions.

Precautionary allergen labels (e.G., 'may contain') help consumers identify possible allergens in foods; however, such labelling is currently voluntary in the EU, leading to inconsistencies in how allergen risks are communicated. As a result, 'may contain' warnings are used so frequently – and often without clear explanation – that they can be confusing and unhelpful for consumers trying to assess actual risk.

Efforts are being made to establish threshold levels for allergens, helping to create more consistent and scientifically backed labelling practices, reducing unnecessary warnings and expanding safe food choices.

Food allergies are more common than you might think, and they can range from mild to serious, life-threatening reactions. But what exactly is a food allergy, and how is it different from an intolerance? If you've ever wondered why some people have to be so careful about what they eat – or if you suspect you might have a food allergy yourself – this article breaks it all down. From symptoms and triggers to testing and treatment, we'll cover everything you need to know to stay safe and informed.

A food allergy occurs when an allergen (a protein in a food, which in the majority of people will not produce an adverse reaction) sets off a chain of reactions involving the immune system.1

Food intolerances don't involve the immune system and are generally less serious than most allergic reactions. They can be due to (i) an enzyme deficiency, e.G. Lactase (the enzyme required to digest the milk sugar lactose) which may be produced in low quantities or none at all by people who are lactose intolerant; (ii) pharmacological (e.G. Due to amines such as histamine or other compounds such as caffeine), where the body may struggle to metabolize specific compounds in foods that contain high quantities of them or (iii) in some cases the mechanism may be undefined.2

An allergic reaction is the response of the body's immune system to normally harmless substances (known as allergens), such as pollens, foods, and house dust mites. When the immune system encounters these substances for the first time, it produces large numbers of antibodies, called IgE antibodies, which bind to the surface of mast cells – a type of immune cell found in tissues throughout the body, especially in the skin, lungs, and digestive tract. This is known as sensitisation. The next time the body encounters that particular allergen, the IgE antibodies on the surface of the mast cells are activated, causing the release of chemicals such as histamine, which cause the allergic symptoms.1

Allergic symptoms can range from mild (causing discomfort), to life threatening. Common symptoms affect the face, skin, respiratory system and the gut. Symptoms affecting the face or skin include a runny or itchy nose, dry mouth, itchy eyes, sneezing, or a rash (itchy red skin or hives). In the windpipe and lungs, allergies can cause wheezing and shortage of breath, and in the gut, symptoms such as abdominal discomfort, nausea, vomiting and diarrhoea may occur.1

A severe allergic reaction is known as anaphylaxis and can be life-threatening. Anaphylaxis causes closing of the throat and difficulty breathing. It may also result in a drop in blood pressure, abdominal pain and vomiting and unconsciousness. People experiencing anaphylaxis should be treated immediately.3

The prevalence of food allergies varies between different ages. In children, 9.3% of the population have a food allergy, which decreases to around 5.0% during adulthood.4 This decline occurs because some children outgrow their allergies, particularly to milk, egg, wheat, and soy, as their immune system develops. However, allergies to peanuts, tree nuts, fish, and shellfish are more likely to persist into adulthood.5

It's also worth noting that the percentage of people who think they're allergic (i.E., self-diagnosis) is higher than the percentage of people who are actually diagnosed by health professionals. This discrepancy highlights the need for accurate diagnosis to avoid that people restrict their diets unnecessarily and ensure reliable prevalence data.

Although many foods or groups of foods can trigger an allergic reaction, 14 of them have been identified as the most common or serious causes of food allergies in the EU. These 14 most common allergens are:6• Celery• Gluten• Crustaceans• Egg• Fish• Lupin• Milk• Molluscs• Mustard• Peanut• Sesame seed• Soybean• Sulphur dioxide/sulphites• Tree nuts

Most allergies begin in childhood, or as a teenager, but it's possible to develop an allergy at any point in your life. Childhood allergies can be outgrown later in life, but that isn't common for late-onset allergies. Mild allergic reactions may become more serious over time, so it's important to see a doctor even for mild reactions.6

An allergic person will not always experience the same symptoms on different occasions. There are a range of factors (affecting the food or person) which might have an effect on the severity of the reaction on any given day. They include:1• How the food has been processed (fried, baked, boiled etc.)• The variability of the food (ripeness, season etc.)• Sleep• Menstrual cycle stage• Psychological factors• Physical activity• Cumulative allergen exposure• Stress• Infection• Alcohol usage• Medication• Climate

These factors may affect the amount of allergen required to cause a reaction in an individual on different occasions. For example, someone experiencing high levels of stress or drinking alcohol might notice aggravated symptoms following exposure to an allergen compared to a period of calm and sobriety.

Doctors use three main testing methods for diagnosing allergies: blood tests, food challenges or elimination tests.7

Blood tests are often in the form of skin prick tests, where the skin is pricked with a drop of the allergen on it, to see if IgE antibodies are produced (indicating an allergic reaction). Other blood tests measure levels of specific IgE antibodies to suspected or known allergens. The likelihood of a clinical reaction increases with higher IgE levels.

Food challenge tests involve the patient eating suspected allergenic foods in gradually increasing amounts to see if allergic symptoms occur. These are always conducted under controlled conditions. Sometimes these tests take the form of double-blind placebo-controlled food challenge tests (DBPCFC). This is where neither the subject nor the investigator knows whether the food contains the allergen under investigation.

In an elimination test, the suspected foods are removed from the diet. If allergic symptoms disappear, suspected foods are gradually reintroduced into the diet in very small quantities while the person is closely monitored for any symptoms. Once all the suspected foods have been checked out, foods causing problems can be avoided.

There is currently no cure for food allergies. The condition must be managed by the susceptible individual's careful avoidance of the allergen-containing food. However, research is being undertaken to try and prevent the initial sensitisation stage in an allergic reaction.

For example, to minimise peanut allergy risk, guidelines recommend introducing peanuts early on when introducing solid foods during complementary feeding.9,10 If your infant has severe eczema, egg allergy, or both (conditions that increase the risk of peanut allergy), introduce peanuts as early as 4 to 6 months of age. If your infant has mild to moderate eczema, it's recommended to introduce peanuts around 6 months of age. Give peanuts crushed, ground, or try a smooth nut butter to reduce the risk of choking. The amount of peanut protein to be eaten per week should be approximately 6 to 7 grams over 3 or more feedings. One feeding (2 g of peanut protein) looks like, for example, 9-10 g or 2 teaspoons of peanut butter or 8 g or 10 whole peanuts (2 ½ teaspoons of grounded peanuts).10

Guidelines also recommend introducing well-cooked, but not raw egg or uncooked pasteurised, egg during complementary feeding to minimise allergy risk.9 Introduce around 2 g egg protein (approximately 1/3 of an egg) per week to your infants' diet, starting from 4 to 6 months of life. It's always best to consult your GP or allergy specialist before introducing peanuts or egg to infant's diets.

Food allergies are managed primarily by avoiding the allergenic food which requires careful reading of ingredient labels. If you accidentally ate a food with an allergen, mild reactions may be treated with antihistamines, while severe reactions, such as anaphylaxis, require an epinephrine injection and emergency medical care. Epinephrine is a hormone that acts on the body in several ways. It relaxes the muscles in the lungs which makes it easier to breathe, it constricts blood vessels to counteract the dangerous drop in blood pressure, and it decreases inflammation, preventing the throat from closing. The injection is usually given in the thigh muscle, and its effects start within minutes. After using epinephrine, emergency medical care is still needed.8Some newer treatments, like immunotherapy, aim to gradually desensitise allergic people by exposing them to small, controlled amounts of the allergen. However, these treatments should be only done under medical supervision.1

If you have a food allergy:8

Read ingredient labels carefully, even for familiar products, as formulations may change. For foods that are not pre-packaged or foods prepared on-site (e.G., a café or restaurant), staff is required by law to provide information on the ingredients and possible allergens.

Be cautious when eating out by asking restaurant staff about potential allergens in meals and risk of cross-contamination in the kitchen.

Avoid cross-contamination by using separate utensils and cookware for allergen-free foods.

Educate family, friends, and caregivers about specific allergies and emergency response procedures.

Carry emergency medication (such as an epinephrine auto-injector) if prescribed by a doctor.

Plan ahead when travelling or attending events, for example by taking safe snacks or meals yourself or by researching restaurants or food options beforehand to find allergy-friendly choices.

Fig. 1 – How can I manage my food allergy?

To alert consumers to the presence of allergens in food products, food companies use allergen labels. There are two types of allergen labels: mandatory and precautionary.11Mandatory labels: A compulsory label to alert consumers to the presence of allergenic ingredients. Under EU law, the fourteen allergens listed above must be declared on the label of the foodstuff if they are used as an ingredient (including those carried over in processing aids, additives and solvents).Precautionary labels: If a priority allergen is not used as an ingredient, but there is a chance that the allergen may be present (through cross contamination), food companies often choose to use a voluntary precautionary label, for example 'may contain X', or 'created in a factory that handles X'.

Fig. 2 – How can I identify food allergens?

Precautionary allergen labelling (PAL) is not legally regulated in the EU, meaning its use is entirely voluntary and varies between manufacturers. This can make it difficult for allergic consumers to assess how much risk a product actually poses.12

As testing methods have improved, food manufacturers can now detect allergens in increasingly trace amounts. To avoid liability, many companies apply PAL broadly, even when the actual risk of cross-contamination is minimal. This had led to overuse of precautionary warnings, significantly limiting food choices for allergic consumers. While some allergic individuals can tolerate trace amounts of allergens in foods, in others such amounts may still cause an (severe) allergic reaction.

Another ongoing challenge is the lack of clear allergen thresholds – the minimum amount of an allergen that could trigger a reaction in sensitive individuals. Currently, there is no standard across the EU for when a PAL statement should be used. To address this, experts are working on establishing threshold doses based on scientific data. There are also discussions within the EU about harmonising PAL rules to ensure that allergen warning provide clear, evidence-based risk communication, rather than just blanket precaution.

Efforts are underway in Europe to establish a 'threshold level' for different allergens. A threshold level refers to the smallest amount of an allergen that is unlikely to trigger a reaction in most allergic individuals. These scientifically determined, risk-based limits could help create a more consistent approach to precautionary allergen labelling (PAL). Under this system, PAL statements would only be required on foods that may contain allergens at or above the threshold level, while products with contamination level below this threshold would be exempt from such warnings.13

This approach would benefit both food manufacturers and people with food allergies. For manufacturers, it would provide clear guidance on when a PAL statement is necessary, reducing unnecessary precautionary warnings. For consumers, it would mean fewer overly cautious labels, making it easier to identify foods that are truly risky and expanding safe food choices. Ultimately, the goal is to ensure that PAL is based on scientific risk assessment rather than broad precaution, improving both safety and clarity in allergen labelling across Europe.

Living with a food allergy can be challenging, but with the right knowledge and precautions, it's totally manageable. While there's no cure yet, science is making strides in allergy research, and clearer food labelling legislation – both in retail and the hospitality sector – is helping people make safer choices. Understanding the difference between food allergies and intolerances, recognising symptoms, and following appropriate precautions are essential steps in managing the condition effectively.Learn more about the most common food allergens and foods that contain them.

References

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Allergy UK. (2025). Anaphylaxis and severe allergic reactions. Accessed 26 March 2025.

Spolidoro G, et al., (2023). Frequency of food allergy in Europe: an updated systematic review and meta‐analysis. Allergy, 78(2), 351-368.

Allergy UK. (2025). Top 14 food allergens. Accessed 26 March 2025.

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the evaluation of allergenic foods and food ingredients for labelling purposes. EFSA Journal 2014; 12(11):3894, 286 pp.

Allergy UK. (2025). Food allergy testing and diagnosing. Accessed 26 March 2025.

Allergy UK. (2025). Food allergy. Accessed 26 March 2025.

Halken S, et al. (2021). EAACI guideline: Preventing the development of food allergy in infants and young children (2020 update). Pediatric Allergy and Immunology, 32(5), 843-858.

Togias A, et al. (2017). Addendum guidelines for the prevention of peanut allergy in the United States: report of the National Institute of Allergy and Infectious Diseases–sponsored expert panel. World Allergy Organization Journal, 10, 1-18.

European Parliament and Council. (2011). Regulation (EU) No 1169/2011 of the European Parliament and of the Council of 25 October 2011 on the provision of food information to consumers, amending Regulations (EC) No 1924/2006 and (EC) No 1925/2006 of the

FAO & WHO. 2023. Risk assessment of food allergens – Part 3: Review and establish precautionary labelling in foods of the priority allergens, Meeting report. Food Safety and Quality Series No. 16. Rome.

ILSI Europe. (2025). Food allergy. Accessed 26 March 2025.

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