Why do eggs trigger reactions in some?

Eggs are a rich source of nutrients including proteins, vitamins, minerals and good fats. But in some people, the protein in the egg can stimulate an immune response, leading to skin allergies or even anaphylactic reactions.

Malaysia-based Nirmal Bhatt is in his 40s and he is one among the many battling egg allergy. He is very conscious of the food he eats and has been avoiding eggs for almost all his life.

“In Malaysia, even if you order vegetarian food, they add eggs. So, I have to particularly tell them that there should be no egg in the food,” says Bhatt, explaining the ordeal he faces every time he goes to a restaurant. Nirmal recalls that he was diagnosed with egg allergy when he was five years old.

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“I avoid eggs all the time,” says Bhatt, who relies on fish and vegetables, especially potatoes and soya as alternative sources of protein. 

Dr P C Kathuria, chest physician and allergy immunotherapy, critical care specialist, National Allergy Centre, New Delhi says that egg allergy is an immunological reaction induced by egg proteins, which are largely present in egg whites. 

Egg allergy symptoms

According to the American College of Allergy, Asthma and Immunology, the symptoms of egg allergy are:

• Vomiting
• Stomach cramps
• Indigestion
• Diarrhoea
• Wheezing
• Shortness of breath, difficulty breathing
• Repetitive cough
• Tightness in throat, hoarse voice
• Weak pulse
• Pale or blue colouring of the skin
• Hives
• Swelling, can affect the tongue and/or lips
• Dizziness
• Confusion

Dr Sujatha Ramesh, an allergist from Manipal Hospitals, Yeshwantpur, Bengaluru, says that egg allergy most commonly presents with rashes (hives) usually immediately after eating eggs. One may also see lip/eye swelling and/or experience difficulty breathing with wheezing and throat tightness. “Egg allergy can range from mild reactions like skin rashes to a severe life-threatening allergic response called anaphylaxis,” Dr Ramesh.

Bhatt faces the typical symptoms of egg allergy reactions every time he consumes eggs unknowingly. “I have acute stomach pain and have to wait for hours for the pain to subside. Sometimes I throw up everything I eat,” he says.

According to a 2020 review published in the International Journal of Molecular Sciences, hypersensitivity or an allergy to chicken egg proteins is a predominant symptomatic condition affecting 1 in 20 children in Australia.

Diagnosis for egg allergy

Dr Ramesh explains that medical personnel should establish the exact nature of the reaction. “Sometimes, it could be just food intolerance and not necessarily food allergy. For example, if one has a headache after eating aged cheese, it is not an allergy, but food intolerance. It’s important to pinpoint the nature and cause of the reaction and distinguish between food intolerance and true allergy. Allergy is an immunological reaction,” she says. Experts mention that a reaction could vary from mild to severe. “The end of the spectrum is where we must be very careful – that is the severe, immediate, life-threatening anaphylaxis,” she points out.

A Skin Prick Test (SPT) and a blood test for specific IgE (Immunoglobulin E antibody) can confirm an egg allergy, says Dr Kathuria. He adds that the severity of egg allergy cannot be detected on the basis of SPT or specific IgE and can only be detected by an Oral Food Challenge (OFC) Test or Component Resolved Diagnosis (CRD). The OFC test is a diagnostic method in which a person suspected of a specific food allergy is made to eat the same food in small qualities and portions are gradually increased under the supervision of an allergy specialist in a hospital setting. In OFC for an egg allergy test, usually baked egg is given. CRD is a diagnostic and prognostic test for egg allergy to detect specific IgE against individual allergen molecules.

There is a need to create awareness about anaphylaxis says, Dr Ramesh. “Anaphylaxis is a severe, rapidly progressing life-threatening reaction, which occurs immediately after eating the allergic foods. Symptoms usually involve more than one organ system. The most common manifestations are rapidly progressing rashes, difficulty breathing, wheezing and swelling/tight sensation inside the throat (laryngeal oedema). There may be associated, stomach pain, cramps, nausea and vomiting. It’s a constellation of rapidly progressing signs and symptoms,” says Dr Ramesh.

For an accurate diagnosis, the doctor has to be very attentive to the food consumption history. “The pattern of these reactions must be evaluated clinically. Based on the history, blood tests are done to look for specific antibodies against eggs via IgE tests. If the person has an egg allergy, then the test results will show elevated levels of egg-specific IgE,” says Dr Ramesh.

Watch out for the hidden ingredients

Dr Ramesh recalls the case of a five-year-old boy from Bengaluru. “This child had a history of anaphylaxis to eggs. He was strictly asked to avoid egg and egg products and the parents were advised to read labels carefully. On the way back from a doctor’s visit, he ate an eggless quiche and immediately had a severe reaction. Fortunately, they had carried his emergency injectable adrenaline, a lifesaver, which his mother administered. Further queries revealed that the so-called eggless quiche was made with custard which had egg as the major ingredient,” says Dr Ramesh.

Dr Ramesh points out that bread, rolls and other baked goods have an egg wash to give them a nice, glossy look. “They brush it with eggs. Eggs are also used as a binder in cutlets, kebabs and several other dishes in restaurants. One must be aware of these hidden ingredients. Ice creams may contain eggs. So might custards, puddings and many deserts,” says Dr Ramesh. He highlights that the treating allergist must come to a conclusion through testing and by analysing the case history, whether the reaction is to raw eggs, partially cooked eggs (such as scrambled eggs) or baked eggs (muffins or cakes). “If the allergic people have tolerated baked eggs, without a reaction, then they can continue taking it, but they should avoid raw eggs to which they have reacted,” says Dr Ramesh.

Dr Kathuria says that people with egg allergy should watch out for cross-contamination.

Though some foods may not have eggs on the ingredient list, while being made, they can come in contact with eggs.

However, most children outgrow egg allergies. Parents should consult an allergy specialist, Dr Ramesh adds. “Infants and young children with egg allergy and eczema have a tendency to develop allergies to other foods. In addition, they may develop asthma as they grow older,” she says.

Speaking to Happiest Health, an IT entrepreneur recalled a traumatic incident from his Hyderabad days in which a former bureaucrat’s wife, known to have an egg allergy, died following an anaphylactic reaction. “Even whisking an egg white for desert can be dangerous,” he says. “For a dinner that the couple hosted, the wife asked a cook to whisk some eggs for a desert. She herself entered the room while the whisking was under way, and she got severe reaction and died.”

Experts also say that if one person in a family has a specific food allergy, it is better and safer if everyone in the family sacrifices the particular food so as to avoid triggers.

Tips to manage your egg allergy

According to Dr Kathuria, people with egg allergies and parents of children with egg allergies must be aware of the following: 

• Those with egg allergy must not eat foods that contain any of the following ingredients: Albumen, albumin, products with any word containing ‘ovo’ or ‘album’, conalbumin, dried egg, eggs from chicken, duck, goose, hen, quail or other poultry product, egg protein, egg substitutes, egg yolk, egg white, frozen egg, globulin, lecithin, livetin, lysozyme, ovalbumin, ovoglobulin, ovomucin, ovomucoid, ovolactohydrolyze protein, ovovitellin, ovomacroglobulin, ovotransferrin, pasteurised egg, silico-albuminate, simplesse and vitellin.
• Look for advisory statements such as may contain egg,’ ‘processed in a facility that also processes egg,’ or ‘manufactured on equipment also used for egg.’
• It is important for anyone preparing the food to wash their hands with soap and water to avoid cross-contamination.
• Make sure to wash hands before eating. If soap and water aren’t available, use hand-cleaning wipes. But don’t use hand sanitiser gels or sprays. Hand sanitisers only get rid of germs — they don’t get rid of egg proteins.
• Keep foods that contain eggs in a separate part of your kitchen so they don’t contaminate your child’s food. When preparing food, wash dishes and utensils with dishwashing soap and hot water to remove any traces of egg.
• Inform the people preparing or serving your child’s food about the egg allergy. When eating outside, it is safer to carry separate food instead of eating at a place where the absence of eggs in the food cannot be guaranteed.
• Children with egg allergy and a history of anaphylactic reactions need to consult a dietician for an egg-free diet. They also need additional care in schools because of the possibility of food contamination and food sharing. In such cases, the dietician should educate the teachers, nurses or the primary care provider at school regarding the treatment of anaphylaxis.