Egg Allergy: What Is It and How Is It Treated?

An egg allergy is more common in children. In this article, learn how to recognize it and what to do about it.

Reviewed and approved by the doctor Diego Pereira.

Written by Saúl Sánchez Arias

Last update: 15 December, 2023

An egg allergy occurs when the immune system interprets egg proteins as harmful substances. Thus, in its attempt to defend the body from these ‘invaders’, it reacts disproportionately and generates an inflammatory and allergic response.

Although it can occur in people of all ages, the most affected are children. According to data reported by the American Academy of Allergy, Asthma & Immunology, this is the second most common food allergy in young children after cow’s milk.

To be more precise, it affects an estimated 0.9% of all children and 1.3% of children under 5 years of age. How to recognize it? What are the risks? Here are all the details.

What is egg allergy and why does it occur?

Egg allergy occurs when the immune system overreacts to the proteins in the egg white or yolk, recognizing them as harmful to the body.

It’s mediated by immunoglobulin E (IgE), which is an antibody that binds to antigens – in this case, egg proteins – and triggers the response in the immune system. Thus, when the affected person ingests egg or its derivatives, his or her body releases histamine and other chemicals that provoke an inflammatory response.

Symptoms can range from mild to severe, and range from a simple rash to anaphylaxis (rare cases). Fortunately, 70% of affected children usually outgrow this problem after the age of 16.

An investigation in International Archives of Allergy and Immunology shows that introducing eggs early in the diet can reduce the risk of children developing this allergy.

The symptoms of an egg allergy

The clinical picture of egg allergy can develop shortly after ingestion of the food or within two hours. It often has characteristics similar to those of other food allergies. It causes skin, gastrointestinal and respiratory symptoms such as the following:

• Diffuse urticaria (hives causing intense itching)
• Itching of the mouth and tongue
• Angioedema (a swelling that occurs under the skin)
• Abdominal pain
• Diarrhea
• Vomiting
• Dehydration
• Nasal congestion and increased mucus
• Sneezing
• Coughing
• Tightness in the chest or shortness of breath

Anaphylaxis

When the allergic reaction is severe, it can trigger a life-threatening anaphylactic reaction. If so, it requires immediate medical intervention, as treatment with adrenaline will be necessary. Warning symptoms are as follows:

• Severe respiratory distress
• Abdominal pain
• Increased heart rate
• Dizziness, drop in blood pressure, and loss of consciousness

Other complications

Apart from anaphylaxis, the immune system’s reaction to egg allergy can lead to other health complications. The most frequent are the following:

• Allergies to other foods, such as milk, peanuts, or soy
• Allergies to dust mites, pollen, or pet dander
• Atopic dermatitis
• Asthma

It’s very important to be aware of the symptoms of egg allergy, however mild they may be. Their severity may vary from one patient to another. And even if at first it may have been mild, it can later manifest itself in a more severe form.

When the physician considers that there is a high risk of anaphylaxis, he/she may indicate an emergency epinephrine injection. This has an auto-injector that facilitates its use.

Egg allergies in children

Egg allergy is considered a childhood disease, since it usually manifests itself in children under 5 years of age. Its first symptoms are usually noticed when eggs are first introduced in the baby’s complementary feeding.

In most cases, allergic children are sensitized to the allergens in the egg white, but not to those in the yolk. Even so, this condition usually resolves in 70% of cases before adolescence.

The remaining percentage continues to experience a persistent allergy into adulthood. These cases deserve special attention, as the risk of severe reactions also increases.

Egg allergies in adults

Egg allergy onset during adulthood is extremely rare. It’s often associated with a history of other types of food allergy. However, cases of sudden allergy have been reported without any history of intolerance.

A publication in Clinical and Molecular Allergy suggests that stress, alterations in the microbiota, inflammatory bowel disorders, and some medications may be involved in the development of this allergy in adulthood.

However, it most often starts in childhood and lasts into adulthood. The prognosis in these cases is not very good, as there is a high risk of severe reactions.

An investigation through International Journal of Molecular Sciences exposes that in adulthood, allergy to egg yolk proteins is more frequent.

When to consult a doctor

It’s essential to seek medical attention if after eating eggs or egg-containing products there are clinical manifestations of an allergy. If possible, a specialist should be consulted as soon as a reaction occurs. Thus, the professional can observe the symptoms and arrive at a diagnosis more easily.

Diagnosis of egg allergy

To carry out a diagnosis of egg allergy, the physician begins with a detailed study of the patient’s clinical history and physical examination. Subsequently, he or she suggests in vitro or in vivo allergy tests to confirm the condition.

According to information from Pediatric Clinics of North America, these tests include the following:

• Measurement of food-specific IgE antibodies
• Skin prick tests
• Atopy patch test (APT)
• A diagnostic elimination diet

During the review of the medical history, any information on dietary egg intake as well as subsequent reactions should be detailed. At this point, it’s also necessary to provide data on a family history of egg allergy or other food allergies.

Treatment of egg allergy

As with other food allergies, the first-line treatment for egg allergy is to avoid consuming eggs and egg products. The physician also suggests a plan of action against the allergy, should it occur. This includes the following:

• Antihistamines. They’re available over the counter and can help calm symptoms in milder cases. They do not help if there is an anaphylactic reaction.
• Emergency epinephrine injections. As mentioned above, this injection is used if there are symptoms of anaphylaxis. It serves to relax the muscles of the airways and constrict the blood vessels.

Oral desensitization therapy

Since eggs are a very common food, present in many food products and even medicines, it’s difficult to avoid them completely. In response to this, an oral desensitization treatment has been developed.

Also called oral immunotherapy, it consists of administering very low doses of the food and gradually increasing the portions so that the body adapts to it. It can last from weeks to months, and works in up to 70% of the cases.

A review reported in Cochrane Library: Cochrane Reviews determined that this treatment has great potential to increase egg tolerance.

It must be supervised by the physician at all times, since it’s possible that allergy symptoms may occur. Patient and family education is key to managing reactions and achieving success with this therapy.

Products that commonly contain eggs

It should be considered that egg is present in many commercial products. Hence the importance of checking labels as part of the strategies to avoid the symptoms of this allergy. It’s often present in the following foods:

• Baked goods
• Industrial ultra-processed products
• Dairy desserts
• Candies and sweets
• Sauces and dressings
• Coffees with cream

Can people with egg allergies eat baked eggs?

The short answer to this question is: maybe. To date, it has been observed that patients with egg allergy tend to tolerate baked goods containing eggs.

In a publication in NIH Research Matters, it’s suggested that this is because the high temperatures of baking help break down the egg proteins that cause allergy.

For this reason, this method of baking is often considered in oral desensitization therapy. With careful monitoring, it appears safe for children to consume baked egg products. Still, medical supervision should be maintained.

Egg allergy, one of the most common food allergies

It should be remembered that egg allergy is the second most common food allergy during childhood. Being attentive to its symptoms is crucial to intervene in a timely and appropriate manner. It should never be ignored that it can lead to life-threatening anaphylactic reactions.

Fortunately, in more than 70% of cases, it’s overcome after adolescence. In all cases, it’s advisable to avoid the presence of eggs and their derivatives in the diet. Only if the doctor suggests a desensitization therapy, it’s possible to gradually incorporate this ingredient into your diet.