Egg Allergy: Causes, Symptoms and Avoidance List
An egg allergy occurs when a person’s immune system overreacts following exposure to eggs or egg derivatives. Eggs are among the most common triggers of food allergy in children, causing reaction in about 2% of children. An allergy to eggs typically begins in infancy and most children (ca 70%) will outgrow the condition by the age of sixteen.
Susceptible people who have been exposed to an egg allergen will usually display symptoms within a few minutes to a few hours. Symptoms of egg allergy often include itchiness, hives, rashes, nausea, stomach cramps and breathing problems. However, severe reactions to eggs may result in a potentially life-threatening anaphylactic shock.
Some individuals can be also allergic to the gases given off by eggs during cooking. In most cases, this condition triggers allergic rhinitis with symptoms such as runny nose or nasal congestion, stuffy head and sinus pressure.
While most individuals are allergic to the whites of eggs, only a few people happen to be allergic to proteins found in the yolk. These people have a condition called bird-egg syndrome with allergic reaction to both egg yolks and inhaled or ingested bird antigens.
There are also people who are only seasonally allergic to eggs, mostly those who have allergies to ragweed and oak pollen and the goosefoot family of weeds. Because the proteins in these airborne allergens are similar to those in eggs, the body confuses the two and a cross-reaction with eggs occurs.
People with an egg allergy need to be aware of the many types and names of egg derivatives, which are found in a variety of foods, because only a trace amount of egg is needed to trigger an allergic attack in some individuals.
Potential Causes and Risk Factors for Egg Allergies
Although some people are allergic only to chicken eggs, most people with egg allergy react to eggs from any fowl, including chickens, ducks, goose, turkey and quail. Eggs and egg derivatives can be found in a broad variety of foods, including (but not limited to):
- Baby food
- Baked goods and baking mixes (e.g., breads, rolls, pretzels, cookies, crackers, cakes, doughnuts, pancakes)
- Breaded or battered fried foods (e.g., chicken nuggets, sausage, meatballs, meat loaf)
- Desserts (e.g., fudge, ice cream, frosting, pudding, sherbet, some chocolate, cream pies, cream puffs, meringue, marshmallows)
- Drinks (e.g., beer, root beer, coffee, wine)
- Pastas (e.g., spaghetti, penne, vermicelli, egg noodles)
- Sauces and salad dressings (e.g., mayonnaise, tarter sauce, bearnaise sauce, hollandaise sauce, Caesar dressing)
- Soups (e.g., noodle soups, egg drop soup, consomme)
Individuals with egg allergy should always check the ingredient label to stay away from products that contain powdered egg, egg solids, egg white and egg white solids, egg yolk and whole egg. It is necessary for them to read product labels each time they shop because food manufacturers change the ingredients in their products from time-to-time.
An egg derivative, such as egg protein, present in a food can be just as dangerous as egg itself to somebody allergic to eggs. However, the name – egg – may not be specifically mentioned anywhere on the ingredient label. Some of the many types of egg derivatives and extracts that do not have the word “egg” in their name include:
- Ovolactohydrolyze proteins
- Silici albuminate
As a general rule, terms containing “albumin” or “ovo” typically signal the presence of egg. In addition, the substance lecithin (which is not mentioned in the above list) is often made with egg yolks. Patients with egg allergies should also know that some brands of egg substitutes actually contain egg whites. Moreover, allergic people should be aware that some shampoos and cosmetics contain egg proteins. And, when the fumes from eggs are inhaled, typically during cooking, hay fever can result.
People with egg allergies or parents of children with egg allergies should inform their health care provider about their condition because some vaccines (e.g., flue, yellow fever, etc.) may contain a trace amount of egg protein.
Several factors may predispose a young child towards an egg allergy. A family history of hay fever (allergic rhinitis), hives, eczema or asthma usually increases the chances that a child will develop one or more food allergies. However, many of these “childhood” allergies gradually go away as children grow and their immune and digestive systems mature.
Symptoms of Egg Allergies
Exposure to eggs can trigger an array of allergic reactions in sensitive individuals. Symptoms usually appear within minutes of eating the food that contains egg or egg derivative, though some may occur up to several hours later. Typical symptoms of an egg allergy include:
- Gastrointestinal problems, such as diarrhea, nausea, vomiting or stomach cramps.
- Nasal or sinus conditions, which are more common when fumes from eggs are inhaled (e.g., during cooking), rather than when eggs are ingested. Symptoms are similar to those associated with the inhalation of dusts or pollens such as sneezing, nasal congestion, stuffy head, runny nose and sinus pressure.
- Respiratory problems, such as coughing or wheezing.
- Skin conditions, such as itchiness, hives, rashes or red bumps.
Some very sensitive individuals may experience a potentially life-threatening condition known as anaphylactic shock. Anaphylactic shock usually involves the constriction of the air passageways and a dangerous drop in blood pressure. Characteristic symptoms of this condition are shortness of breath, tightening in the chest or throat, choking and loss of consciousness. Patients who experience symptoms involving two or more body systems (anaphylaxis) should seek immediate medical assistance.
Several conditions with similar symptoms may be mistaken for a food allergy including food intolerances, food poisoning, irritable bowel syndrome and other gastrointestinal conditions. Egg intolerance is the most common condition to be confused with egg allergy. It occurs when the body is unable to digest a certain component of egg. Food intolerance is not an allergic reaction because it does not involve the immune system. As with egg allergies, treatment of egg intolerance usually involves the elimination of eggs and their derivatives from the diet.
Diagnosing Egg Allergies
The techniques used to diagnose egg allergies are largely identical to those used in other common food allergies such as milk allergies (see this post for more details). However, diagnosis of this particular type of allergy may sometimes be more complicated because many people with egg allergies also react to egg proteins within other foods.
Treatment of Egg Allergies
The only proven technique of treating an egg allergy is to eliminate eggs, egg products and egg derivatives completely from the diet. Inhaling the gases produced by cooking eggs as well as any direct skin contact with the problem food should also be avoided.
Egg-sensitive individuals or their parents should become familiar with the many types of egg derivatives commonly found in today’s foods (see the section “Potential Causes and Risk Factors for Egg Allergies” above). Extracts like albumin, globulin or ovalbumin can be just as dangerous to sensitive people as plain eggs and should be avoided with equal care. Patients should also be careful when using commercial egg substitutes in cooking because some brands contain egg whites.
An allergic reaction to chicken eggs can in some instances be avoided by substituting them with eggs of other birds such as duck or quail. However, patients should consult their allergist before attempting this switch.
It is not always possible to prevent contact with eggs and an allergic reaction does sometimes occur. In such situations, medications can be used to relieve allergy-related symptoms. Allergic reactions to eggs, like most other food allergies, usually result in symptoms that affect the skin, nose, throat, digestive system and the lungs. Antihistamines, bronchodilators and corticosteroids are typically prescribed to treat (but not to prevent) these symptoms. In addition, patients who are susceptible to the most serious and potentially fatal allergic reaction called anaphylaxis, or their parents, are often advised to carry an epinephrine shot, a powerful bronchodilator that helps to reverse the severe breathing problems.