Egg allergies are one of the most common allergies of childhood. Both the yolk and the white of eggs are made of numerous proteins and are therefore potentially allergenic, although egg whites cause more reactions than yolks. Although most egg allergies begin in childhood, in rare cases egg allergies develop at older ages. So if you or an adolescent child develop allergy symptoms after consuming eggs, consult an allergist. As many as two-thirds of children who are allergic to eggs outgrow their egg allergies by age seven.
People with allergies to hen's eggs may cross-react to two classes of foods: first, other types of eggs (like duck and quail eggs), and second, poultry, especially chicken. While most people who are sensitive to eggs can eat chicken, there is one protein that is present in both eggs and poultry -- alpha-livetin, or chicken serum albumin -- that can cause allergies to both foods. This protein has also been identified as the cause of the "bird-egg syndrome," in which people who have a lot of contact with birds can become sensitized to bird feathers and subsequently develop egg allergies.
Egg allergies are the most common trigger of eczema (atopic dermatitis), especially in children. Other common symptoms of egg allergies are hives (urticaria) and redness and swelling (angioedema). Egg allergy is a rare cause of anaphylactic shock.
Flu vaccines are cultured in chicken eggs. Therefore, there is a potential for reaction in egg-allergic patients who receive the influenza vaccine. Current protocol according to the American College of Allergy, Asthma & Immunology is to administer a skin test using the flu vaccine. If this is positive, the doctor and patient will determine whether the patient's flu risk justifies using the flu vaccine and, if so, giving the shot in an allergist's office or hospital to treat emergency symptoms if necessary. Flu treatments, like Tamiflu, do not contain eggs. For more information, see Vaccines and Egg Allergies.
Eggs are not as difficult to avoid as dairy or soy, but they are present in a variety of foods. All mass-market mayonnaise contains eggs. Many baked goods, batters, and pretzels do too; be especially wary of any shiny baked good, as egg whites are brushed on bread or pastries to create this effect. Some pastas are made from eggs. Eggs are sometimes used to thicken sauces or to bind casseroles or meat loafs. The fat substitute Simplesse is also made from egg protein. Also be aware of ice creams; French- and Italian-style ice creams, or gelati, are made from eggs.
As one of the eight most common food allergens in the United States, eggs are covered by current FDA labeling regulations that require the presence of eggs to be marked on labels in bold print and clear English. However, it's advisable to learn the different names eggs can appear on in labels -- there are quite a few. This can provide an added measure of security when labels are unclear. Consider bringing a list to the grocery store or to restaurants.
While avoidance is the primary treatment for egg allergy, there is some evidence that desensitization therapy (in which patients are given increasing quantities of an allergen over a long period of time) is effective in the treatment of egg allergy.
Eczema (atopic dermatitis) is a chronic condition that is strongly associated with egg allergy. Avoiding allergic triggers may help alleviate symptoms. Your doctor may also recommend antihistamines, steroids, or other treatments. If eczema is a problem and you are allergic to eggs, be aware that simply removing eggs from your diet may not completely cure your eczema. Eczema does, however, tend to resolve on its own in early childhood.
Some people with egg allergies are not sensitive to eggs that have been cooked, although this is the exception rather than the rule. If your history indicates this might be true for you, your allergist will instruct you on which foods might be safe to eat.
The skills for avoiding eggs in the foods you eat are the same as those for avoiding any other allergen. Do be alert to the possibility of cross-contamination. Knives that are used to cut egg-free baked goods should be washed thoroughly beforehand. Also be on the lookout for the possibility of eggs as a hidden allergen in non-food products. Eggs are the main ingredient in tempera paint.
A variety of substitutes for egg-containing products are available at major supermarkets and online; you can find more at smaller health-food stores. Here are a few you may find particularly useful:
- About.com's Guide to Vegetarian Cuisine recommends Vegenaise as an egg-free alternative to mayonnaise.
- Egg replacers can leaven baked goods, though you'll need to add moisture in the form of water or butter. Caution: don't buy cholesterol-lowering egg substitute products available in supermarket refrigerator sections as egg replacements for allergies without reading labels thoroughly. Almost all are made from eggs.
- Egg-free pasta is easy to find, as most dried pastas are simple combinations of durum semolina and water. Fresh pasta, however, is a far dicier proposition. As with all food, read labels carefully. Macaroni and other tube-shaped pastas are more likely to contain eggs than flat noodles.
- Orgran and Cherrybrook Kitchen are two of the larger manufacturers of baking mixes and other specialty products for egg (and other) allergies. Among the products they offer are egg-free pancake, bread, and frosting mixes.
Sources:
Alessandri, C., et al. "Anaphylaxis to Quail Egg." Allergy. Jan. 2005 60(1): 128-29.
American College of Allergy, Asthma & Immunology. Flu Vaccine and Egg Allergy Public Education Fact Sheet. 31 May 2007.
Heine, R.G., N. Laske, and D.J. Hill. "The Diagnosis and Management of Egg Allergy." Current Allergy and Asthma Reports. Mar. 2007 6(2): 145-52.
Quirce, S., et al. "Chicken Serum Albumin (Gal d 5) is a Partially Heat-Labile Inhalant and Food Allergen Implicated in the Bird-Egg Syndrome." Allergy August 2001 56(8): 754-62. 31 May 2007.
des Roches, A., et al. "Tolerance to Cooked Egg in an Egg Allergic Population." Allergy July 2006 61(7): 900-01.
Romeira, A.M., et al. "Egg Allergy: To Be or Not To Be Boiled." Allergy. June 2003 58(6): 533-34. 31 May 2007.
Unsel, M., et al. "New Onset Egg Allergy In An Adult." Journal of Investigational Allergology and Clinical Immunology 2007 Vol. 17(1): 55-58. 31 May 2007.
