November 22, 2022 | Black & Kletz Allergy
Egg allergy is second only to milk allergy in prevalence among infants and young children. It affects about 1 to 2 % of young children overall. It is also the most common food allergy in children with eczema.
Proteins found in egg whites are generally responsible for causing allergic reactions in egg-allergic individuals. Although the ovalbumin is the most abundant protein in egg white, it is the protein ovomucoid that is generally responsible for egg allergy in most children. Ovalbumin is heat labile. The heating process denatures the protein ovalbumin and as a result of heating, the new heated protein is structurally different. Since the heated proteins are structurally different, the majority of egg-allergic children will not react to baked egg products that have been heated during the baking process. This suggests that children who have specific IgE antibodies primarily to ovalbumin are likely to tolerate heated forms of egg. On the other hand, the protein ovomucoid, which is also found in egg white, is not altered by extensive heating and thus is responsible for most of the egg allergies in children.
Clinical Manifestations:
- Immediate hypersensitivity (Type I or IgE antibody mediated) reactions are the most common type of allergic reaction that occurs in egg-allergic individuals. Symptoms usually begin within minutes of egg exposure. Skin manifestations such as itching, rashes, hives, and/or soft tissue swellings are the most common symptoms. Respiratory symptoms such as chest tightness, coughing, wheezing and/or shortness of breath can rapidly progress in severity. Allergic reactions to eggs can also result in gastrointestinal symptoms such as abdominal pain, abdominal bloating, nausea, vomiting, and/or diarrhea.
- Egg allergy most commonly manifests itself in the second half of infancy.
- Egg allergy can be potentially life-threatening (e.g., vocal cord swelling can rapidly lead to difficulty in breathing and loss of consciousness)
- Food-dependent, exercise-induced anaphylaxis with egg as the trigger has been reported. In other words, an individual can eat an egg and then exercise within a certain period of time (i.e., usually within 2 hours) and then develop anaphylaxis as a result of the combination of egg plus exercise. It is interesting to note that this individual may be fine just eating an egg or just exercising, but when done sequentially, anaphylaxis may occur.
- Bird-egg syndrome is a condition where the primary sensitization is to airborne bird allergens and there is secondary sensitization or cross reactivity with the protein albumin in egg yolk. These patients experience respiratory symptoms (i.e., runny nose, nasal congestion, post-nasal drip, sneezing, itchy eyes, watery eyes, puffy eyes, redness of the eyes, chest tightness, coughing, wheezing, shortness of breath) with bird exposure and allergic symptoms with egg ingestion.
- Egg allergy can present as infantile atopic dermatitis (i.e., eczema). Children with eczema and asthma are at increased risk for more severe reactions.
- Egg allergy is one of the common triggers of symptoms in certain gastrointestinal disorders such as eosinophilic esophagitis (EoE) and food protein induced enterocolitis (FPIES).
Diagnosis:
- A comprehensive history of one’s exposure to egg products (both cutaneous and oral), time of onset of specific symptoms after exposure, rapidity of progression, duration of the reaction, and resolution of symptoms are all necessary to help make the diagnosis of an egg allergy.
- Skin prick tests (SPT) with egg white and egg yolk antigens
- Laboratory tests for blood levels of specific IgE antibodies to egg
- Oral food challenge (OFC), a gold-standard for the confirmation of the diagnosis of food allergy.
Treatment:
- The most straightforward approach in managing any food allergy is the complete avoidance of the culprit food. Eliminating egg white and egg yolk from the diet can be difficult and can pose nutritional as well as quality-of-life concerns.
- The evaluation of the allergy followed by an oral food challenge to extensively heated egg is an option since a majority of those with egg allergy will tolerate egg in extensively heated (baked) products, such as a muffin.
- Oral immunotherapy (OIT) is a promising treatment method, though not yet FDA-approved.
- Epinephrine auto-injectors are prescribed for use in the case of a reaction following inadvertent exposure to egg products. Some of the more common names of epinephrine auto-injectors may include EpiPen, Auvi-Q, and Adrenaclick. It should be noted that if an individual uses their auto-injector, that person should go immediately to the closest emergency room.
- Children with egg allergy should be monitored for the resolution of the allergy since most will outgrow the allergy in childhood. Monitoring for resolution includes assessing the history of any accidental exposures and reactions and serial testing for sensitization using laboratory tests, skin prick testing, and/or oral food challenges.
Immunizations:
- Children with egg allergy should not receive yellow fever vaccinations due to an increased risk of allergic reactions since the vaccine is produced using chicken embryos.
- Egg-allergic children can safely receive the influenza and MMR (mumps, measles, rubella) vaccinations despite the use of egg-based technology since the amount of egg protein is incredibly small. It is recommended however that the vaccination be given in a doctor’s office and observed for 30 minutes after the injection. There are also a couple of influenza vaccines that do not contain any egg protein that are available.
Prevention:
The early introduction of egg can provide protection against egg allergy for at least some children who are at high risk for developing an egg allergy. Children at risk may need to undergo a comprehensive evaluation to see if the early introduction of eggs in the diet is appropriate.
The board certified allergy doctors at Black & Kletz Allergy have been diagnosing egg allergy and other food allergies in both adults and children in patients in the Washington, DC, Northern Virginia, and Maryland metropolitan area for more than 50 years. Black & Kletz Allergy has 3 offices in the Washington, DC metro area with locations in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. All of our offices have on-site parking and the Washington, DC and McLean, VA offices are Metro accessible. We offer a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line. If you think or know you have a food allergy, please call us to make an appointment at one of our conveniently located offices. Alternatively, you may click Request an Appointment and we will respond within 24 hours by the next business day. The allergy specialists at Black & Kletz Allergy are confident that we will be able to help you identify your food allergies and any other allergy you may have. The allergists at Black & Kletz Allergy are dedicated to providing you with the best quality allergy, asthma, and immunology care in a professional and caring environment.
