Egg allergy occurs when the immune system interprets the proteins in this food as harmful substances. In this way, 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 released by the American Academy of Allergy, Asthma & Immunology, this is the second most common food allergy in young children after that caused by cow’s milk.
To be more precise, it is estimated that it affects 0.9% of all children and 1.3% of children under 5 years of age. How to recognize it? What are your risks? Next, we tell you all the details.
What is an egg allergy and why does it occur?
Egg allergy occurs when the immune system overreacts to the proteins in the white or yolk of this food, after recognizing them as harmful compounds for the body.
It is mediated by immunoglobulin E (IgE), which is an antibody that binds to antigens —in this case, egg proteins—and which triggers the response in the immune system. Thus, when the affected person eats eggs or their derivatives, their body releases histamine and other chemicals that cause an inflammatory response.
Symptoms can range from mild to severe, ranging from a simple rash to anaphylaxis (rare cases). Fortunately, 70% of affected children usually outgrow this problem after the age of 16.
Research in the International Archives of Allergy and Immunology states that introducing eggs early in the diet can reduce the risk of children developing this allergy.
Egg Allergy Symptoms
The clinical picture of egg allergy can develop shortly after eating the food, or after two hours. Often, it presents characteristics similar to those of other food allergies. Thus, it causes skin, gastrointestinal and respiratory symptoms such as the following:
- Diffuse urticaria (hives that cause intense itching).
- Itching of the mouth and tongue.
- Angioedema (a swelling that occurs under the skin).
- Abdominal pain.
- Nasal congestion and increased mucus.
- Tightness in the chest or shortness of breath.
When the allergic reaction is severe, it can trigger a life-threatening anaphylactic reaction . If so, it requires immediate medical intervention, as a treatment with adrenaline will be necessary. The warning symptoms are the following:
- Severe respiratory distress.
- Abdominal pain.
- Increased heart rate.
- Dizziness, drop in blood pressure, and loss of consciousness.
Beyond 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.
It is very important to be aware of the symptoms of an egg allergy, however mild they may be. Its severity may vary from one patient to another. And although at first, it was mild, it can later manifest itself in a more serious way.
When the doctor considers that there is a high risk of anaphylaxis, an emergency injection of epinephrine may be ordered. This has an autoinjector that facilitates its use.
Allergy 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 noticed when introducing the egg in the baby’s complementary feeding.
In most cases, allergic children are sensitized to allergens in the egg white, but not in the yolk. Even so, this condition usually resolves in 70% of cases before adolescence.
The remaining percentage continues to experience persistent allergies well into adulthood. These cases deserve special attention since the risk of serious reactions is also increased.
Allergy in adults
Egg allergy onset during adulthood is extremely rare. It is often associated with a history of other types of food allergies. However, cases of sudden allergies 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, most of the time it starts in childhood and lasts until adulthood. Their prognosis in these cases is not very good, since there is a high risk of suffering serious reactions.
An investigation through the International Journal of Molecular Sciences shows that allergy to egg yolk proteins is more frequent in adulthood.
When should you see the doctor?
It is essential to seek medical attention if after eating eggs or products containing eggs there are clinical manifestations of allergy . If possible, see a specialist as soon as the reaction occurs. Thus, the professional can observe the symptoms and reach the diagnosis more easily.
Diagnosis of egg allergy
To carry out a diagnosis of allergy to eggs, the doctor begins with a detailed study of the clinical history and a physical examination of the patient. After this, he suggests in vitro or in vivo allergy tests to confirm the condition.
According to information from the Pediatric Clinics of North America, these exams cover the following:
- Measurement of food-specific IgE antibodies.
- Skin prick tests.
- Atopy patch test (APT).
- Diagnostic elimination diet.
During the review of the clinical history, it is necessary to detail all the information on the dietary intake of eggs, as well as the subsequent reactions. A family history of egg allergy or other food allergies also needs to be provided at this point.
Egg allergy treatment
As in other food allergies, the first line of treatment against egg allergy is to avoid the consumption of this food, as well as its derivatives. The doctor also suggests an allergy action plan, should one occur. This includes the following:
Antihistamines. They are available over the counter and can help calm the symptoms in the mildest cases. They do not help if there is an anaphylactic reaction.
Emergency epinephrine injections. As we have discussed, this injection is used if there are symptoms of anaphylaxis. It works to relax the muscles of the airways and to narrow the blood vessels.
Products that usually contain egg
It must be considered that the egg is present in many commercial products. Hence the importance of reviewing labels as part of the strategies to avoid the symptoms of this allergy. It is frequently present in the following foods:
- Bakery products.
- Industrial ultra-processed.
- Dairy desserts.
- Candies and sweets.
- Sauces and dressings.
- Coffees with cream.
Can people with an egg allergy eat baked eggs?
The short answer to this question is: maybe. To this day, it has been observed that patients with an egg allergy tend to tolerate baked goods that contain eggs.
An NIH Research Matters publication suggests this is because high baking temperatures help break down the allergy-causing egg proteins.
For this reason, this method of cooking is frequently considered in oral desensitization therapy. With careful monitoring, it seems safe for children to consume baked egg products. Even so, it is necessary to maintain medical supervision.
It must 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 not be ignored that it can lead to life-threatening anaphylactic reactions.
Fortunately, in more than 70% of cases it is overcome after reaching adolescence. In all cases, it is advisable to avoid the presence of eggs and their derivatives in the diet. Only if the doctor suggests desensitization therapy, it is possible to gradually incorporate this ingredient into the diet.