Egg allergy
Encyclopedia
Egg allergy is a type of food allergy
. It is a hypersensitivity
to diet
ary substances from the yolk or whites of eggs
, causing an overreaction of the immune system
which may lead to severe physical symptoms for millions of people around the world.
Egg allergy appears mainly, but not exclusively, in children. In fact, it is the second most common food allergy in children. (The most common is cows' milk allergy). It is usually treated with an exclusion diet
and vigilant avoidance of foods that may be contaminated with egg. The most severe food allergy reaction is called anaphylaxis
and is an emergency situation requiring immediate attention and treatment with epinephrine. The Asthma and Allergy Foundation of America
estimates that most children outgrow egg allergy by the age of five, but some people remain allergic for a lifetime.
: ovomucoid, ovalbumin
, ovotransferrin
, and lysozyme
; ovomucoid, also called Gal d 1, is the most common target of immune system attack. The egg yolk
contains several potential antigens: livetin, apovitillin, and vosvetin.
Some research on lysozyme
and ovotransferrin
suggests that, perhaps, one of the causes of the allergy is from the chelating capacity of the proteins with metals, especially those of heavy metals
. However, little scientific information is available currently on the direct relationships of the heavy metals in hen eggs and egg allergy.
A person who reacts only to a protein in the egg yolk may be able to easily tolerate egg whites, and vice versa. Some people will be allergic to proteins in both the egg white and the egg yolk. Egg yolk allergies may be somewhat more common in adults. A small number of people who are allergic to eggs will develop an allergy to chicken or other poultry meats.
Most people who are allergic to eggs avoid eating any form of egg or egg component. For people with a more serious allergic reaction to eggs, urticaria (hives) and inflammation can occur and as such, doctors suggest that the person carries around an EpiPen
.
(AAAAI) meeting, 50% of patients outgrew egg allergy by age 17. Of those patients who outgrew it, 45% did so by age 5. Children who outgrew the allergy tended to have peak IgE
levels at around age one, which then decline.
does contain egg proteins. Egg-allergic individuals may react to egg protein(s) in the vaccine (or to gelatin or neomycin if they are allergic to that). If an individual is unable to take the vaccine, vaccinating all other members of their family can help protect them from the flu
.
Different brands and even individual batches of flu vaccine do vary in their egg protein content. Allergist formerly used skin testing with flu vaccine to predict if receiving the flu shot might be safe, but the results of this type of testing are totally unpredictive and this type of testing should be abandonded. Instead, the age-appropriate immunization material containing the lowest amount of egg proteins should be chosen, then a 1/10 dose should be given followed by a 30 observation period in a medical setting fully equipped to treat any possible reaction. Ovalbumin is usually used as a marker for the egg proteins. Vaccines available as recently as 2010 in the US contained up to 21 mcg of ovalbumin per 0.5 mL dose. In 2011 the ovalbumin content varies from less than 5.0 mcg/dose down to less than 0.05 mcg/dose, depending on the brand. One study done on 83 egg allergic patients resulted in a lack of serious reactions at doses of ovalbumin ranging from 0.10 mcg to 0.60 mcg. Thus so some brands available in the US in 2011 are probably safe for most egg allergic patients (administered with caution), but others may not be. For reference modern MMR vaccine (which is generally accepted now to be well tolerated by egg allergic patients, but which is still given with caution) was shown in a 2009 study reported in the BMJ to contain 0.0005 to 0.0010 mcg/dose [0.5 to 1.0 ng/dose). REFERENCE: June 2011 UPTODATE.com monograph on "influenza vaccine and egg allergy" and the NIH Expert Panel Report on Food Allergy, December 2010.
Egg proteins can also be found in yellow fever vaccine
and MMR vaccine
. The quantity of egg protein in a dose of MMR vaccine is approximately 40 picograms (much lower than in influenza vaccine, which contains approximately 0.02-1.0 micrograms), and this is believed to be associated with a much lower risk.
to reduce oil/water separation (mayonnaise), a binder (water binding and particle adhesion, as in meatloaf), or an aerator (cakes, especially angel food). Some commercial egg replacers can substitute for particular functions (potato starch
and tapioca
for water binding, whey protein
for aeration or particle binding, or soy lecithin for emulsification). For home use, one-half cup of applesauce
can replace one egg in some baking recipes.
Most people find it necessary to strictly avoid any item containing eggs, including:
Ingredients that sometimes include egg are:
liberators, also provoke a nonallergic response in some people. In this situation, proteins in egg white directly trigger the release of histamine from mast cell
s on contact. Because this mechanism is classified as a pharmacological reaction, or "pseudoallergy
", the condition is considered a food intolerance
instead of a true IgE-based allergic reaction.
The response is usually localized, typically in the gastrointestinal tract. Symptoms may include abdominal pain, diarrhea, or any symptoms of histamine release. It can result in an anaphylactoid reaction, which is clinically indistinguishable from true anaphylaxis
, if sufficiently strong.
Some people with this condition tolerate small quantities of egg whites. They are more often able to tolerate well-cooked eggs, such as found in cake or dried egg-based pasta, than loosely cooked eggs, such as fried eggs or meringues, or uncooked eggs.
Food allergy
A food allergy is an adverse immune response to a food protein. They are distinct from other adverse responses to food, such as food intolerance, pharmacological reactions, and toxin-mediated reactions....
. It is a hypersensitivity
Hypersensitivity
Hypersensitivity refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. These reactions may be damaging, uncomfortable, or occasionally fatal. Hypersensitivity reactions require a pre-sensitized state of the host. The four-group classification...
to diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
ary substances from the yolk or whites of eggs
Egg (food)
Eggs are laid by females of many different species, including birds, reptiles, amphibians, and fish, and have probably been eaten by mankind for millennia. Bird and reptile eggs consist of a protective eggshell, albumen , and vitellus , contained within various thin membranes...
, causing an overreaction of the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
which may lead to severe physical symptoms for millions of people around the world.
Egg allergy appears mainly, but not exclusively, in children. In fact, it is the second most common food allergy in children. (The most common is cows' milk allergy). It is usually treated with an exclusion diet
Dieting
Dieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...
and vigilant avoidance of foods that may be contaminated with egg. The most severe food allergy reaction is called anaphylaxis
Anaphylaxis
Anaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
and is an emergency situation requiring immediate attention and treatment with epinephrine. The Asthma and Allergy Foundation of America
Asthma and Allergy Foundation of America
The Asthma and Allergy Foundation of America is a non-profit organization dedicated to finding a cure for and controlling asthma, food allergies, nasal allergies and other allergic diseases. AAFA's mission is also to educate the public about these diseases...
estimates that most children outgrow egg allergy by the age of five, but some people remain allergic for a lifetime.
Antigens
Most people who are allergic to hen's eggs have antibodies which react to one of four proteins in the egg whiteEgg white
Egg white is the common name for the clear liquid contained within an egg. In chickens it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms around either fertilized or unfertilized egg yolks...
: ovomucoid, ovalbumin
Ovalbumin
Ovalbumin is the main protein found in egg white, making up 60-65% of the total protein. Ovalbumin displays sequence and three-dimensional homology to the serpin superfamily, but unlike most serpins it is not a serine protease inhibitor...
, ovotransferrin
Ovotransferrin
Ovotransferrin is a glycoprotein of egg white albumen. Transferrins are iron binding proteins and acute phase reactants of animal serum. The sequence of ovotransferrin is similar to that observed for serum transferrin in many species. However, structurally this protein differs from its serum...
, and lysozyme
Lysozyme
Lysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, are glycoside hydrolases, enzymes that damage bacterial cell walls by catalyzing hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between...
; ovomucoid, also called Gal d 1, is the most common target of immune system attack. The egg yolk
Egg yolk
An egg yolk is a part of an egg which feeds the developing embryo. The egg yolk is suspended in the egg white by one or two spiral bands of tissue called the chalazae...
contains several potential antigens: livetin, apovitillin, and vosvetin.
Some research on lysozyme
Lysozyme
Lysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, are glycoside hydrolases, enzymes that damage bacterial cell walls by catalyzing hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between...
and ovotransferrin
Ovotransferrin
Ovotransferrin is a glycoprotein of egg white albumen. Transferrins are iron binding proteins and acute phase reactants of animal serum. The sequence of ovotransferrin is similar to that observed for serum transferrin in many species. However, structurally this protein differs from its serum...
suggests that, perhaps, one of the causes of the allergy is from the chelating capacity of the proteins with metals, especially those of heavy metals
Heavy metals
A heavy metal is a member of a loosely-defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. Many different definitions have been proposed—some based on density, some on atomic number or atomic weight,...
. However, little scientific information is available currently on the direct relationships of the heavy metals in hen eggs and egg allergy.
A person who reacts only to a protein in the egg yolk may be able to easily tolerate egg whites, and vice versa. Some people will be allergic to proteins in both the egg white and the egg yolk. Egg yolk allergies may be somewhat more common in adults. A small number of people who are allergic to eggs will develop an allergy to chicken or other poultry meats.
Diagnosis
Diagnosis is generally made through a combination of skin prick testing or blood testing and detailed records of all foods and drink the person regularly intakes.Treatment
There is currently no cure for egg allergy.Most people who are allergic to eggs avoid eating any form of egg or egg component. For people with a more serious allergic reaction to eggs, urticaria (hives) and inflammation can occur and as such, doctors suggest that the person carries around an EpiPen
EpiPen
An epinephrine autoinjector is a medical device used to deliver a measured dose of epinephrine using autoinjector technology, most frequently for the treatment of acute allergic reactions to avoid or treat the onset of anaphylactic shock.Trade names for this device include EpiPen, Twinject,...
.
Prognosis
In a study presented at the 2007 American Academy of Allergy, Asthma, and ImmunologyAmerican Academy of Allergy, Asthma, and Immunology
The American Academy of Allergy, Asthma & Immunology Founded in 1943, the AAAAI is a professional medical membership organization of nearly 6,500 allergist/immunologists and related professionals around the world with advanced training and experience in allergy, asthma and other immunologic diseases...
(AAAAI) meeting, 50% of patients outgrew egg allergy by age 17. Of those patients who outgrew it, 45% did so by age 5. Children who outgrew the allergy tended to have peak IgE
Immunoglobulin E
Immunoglobulin E is a class of antibody that has been found only in mammals. IgE is a monomeric antibody with 4 Ig-like domains...
levels at around age one, which then decline.
Vaccine hazard
The flu vaccine is typically made using chicken embryo, and as a result the final vaccineVaccine
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins...
does contain egg proteins. Egg-allergic individuals may react to egg protein(s) in the vaccine (or to gelatin or neomycin if they are allergic to that). If an individual is unable to take the vaccine, vaccinating all other members of their family can help protect them from the flu
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
.
Different brands and even individual batches of flu vaccine do vary in their egg protein content. Allergist formerly used skin testing with flu vaccine to predict if receiving the flu shot might be safe, but the results of this type of testing are totally unpredictive and this type of testing should be abandonded. Instead, the age-appropriate immunization material containing the lowest amount of egg proteins should be chosen, then a 1/10 dose should be given followed by a 30 observation period in a medical setting fully equipped to treat any possible reaction. Ovalbumin is usually used as a marker for the egg proteins. Vaccines available as recently as 2010 in the US contained up to 21 mcg of ovalbumin per 0.5 mL dose. In 2011 the ovalbumin content varies from less than 5.0 mcg/dose down to less than 0.05 mcg/dose, depending on the brand. One study done on 83 egg allergic patients resulted in a lack of serious reactions at doses of ovalbumin ranging from 0.10 mcg to 0.60 mcg. Thus so some brands available in the US in 2011 are probably safe for most egg allergic patients (administered with caution), but others may not be. For reference modern MMR vaccine (which is generally accepted now to be well tolerated by egg allergic patients, but which is still given with caution) was shown in a 2009 study reported in the BMJ to contain 0.0005 to 0.0010 mcg/dose [0.5 to 1.0 ng/dose). REFERENCE: June 2011 UPTODATE.com monograph on "influenza vaccine and egg allergy" and the NIH Expert Panel Report on Food Allergy, December 2010.
Egg proteins can also be found in yellow fever vaccine
Yellow fever vaccine
Yellow fever vaccine is a vaccine used against yellow fever.The vaccine consists of a live, but attenuated, strain of the yellow fever virus called 17D. The 17D vaccine has been used commercially since the 1950s. The mechanisms of attenuation and immunogenicity for the 17D strain are not known...
and MMR vaccine
MMR vaccine
The MMR vaccine is an immunization shot against measles, mumps, and rubella . It was first developed by Maurice Hilleman while at Merck in the late 1960s....
. The quantity of egg protein in a dose of MMR vaccine is approximately 40 picograms (much lower than in influenza vaccine, which contains approximately 0.02-1.0 micrograms), and this is believed to be associated with a much lower risk.
Cooking without eggs
In cooking, eggs are multifunctional: they may act as an emulsifierEmulsion
An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...
to reduce oil/water separation (mayonnaise), a binder (water binding and particle adhesion, as in meatloaf), or an aerator (cakes, especially angel food). Some commercial egg replacers can substitute for particular functions (potato starch
Potato starch
Potato starch is starch extracted from potatoes. The cells of the root tubers of the potato plant contain starch grains . To extract the starch, the potatoes are crushed; the starch grains are released from the destroyed cells...
and tapioca
Tapioca
Tapioca is a starch extracted Manihot esculenta. This species, native to the Amazon, Brazil, Colombia, Venezuela, Cuba, Puerto Rico, Haiti, the Dominican Republic, Honduras, and most of the West Indies, is now cultivated worldwide and has many names, including cassava, manioc, aipim,...
for water binding, whey protein
Whey protein
Whey protein is a mixture of globular proteins isolated from whey, the liquid material created as a by-product of cheese production. Some preclinical studies in rodents have suggested that whey protein may possess anti-inflammatory or anti-cancer properties; however, human data is lacking...
for aeration or particle binding, or soy lecithin for emulsification). For home use, one-half cup of applesauce
Applesauce
Apple sauce or applesauce is a purée made of apples. It can be made with peeled or unpeeled apples and a variety of spices . Fruit flavorings or sweeteners such as sugar, high-fructose corn syrup, or sucralose are also commonly added...
can replace one egg in some baking recipes.
Most people find it necessary to strictly avoid any item containing eggs, including:
- Albumin
- Apovitellin
- Cholesterol-free egg substitute (e.g. Eggbeaters)
- Dried egg solids, dried egg
- Egg, egg white, egg yolk
- Egg wash
- EggnogEggnogEggnog, or egg nog, is a sweetened dairy-based beverage traditionally made with milk and/or cream, sugar, beaten eggs , and liquor...
- Fat substitutes (some)
- Globulin
- Livetin
- Lysozyme
- MayonnaiseMayonnaiseMayonnaise, , often abbreviated as mayo, is a sauce. It is a stable emulsion of oil, egg yolk and either vinegar or lemon juice, with many options for embellishment with other herbs and spices. Lecithin in the egg yolk is the emulsifier. Mayonnaise varies in color but is often white, cream, or pale...
- MeringueMeringueMeringue is a type of dessert made from whipped egg whites and sugar, occasionally some recipes may call for adding an acid such as cream of tartar or a small amount of vinegar and a binding agent such as cornstarch found in icing sugar which may be added in addition to the corn starch which...
or meringue powder - Ovalbumin
- Ovoglobulin
- Ovomucin
- Ovomucoid
- Ovotransferrin
- Ovovitelia
- Ovovitellin
- Powdered eggs
- Silici albuminate
- Simplesse
- Trailblazer
- Vitellin
- Whole egg
Ingredients that sometimes include egg are:
- Artificial flavoring
- Lecithin
- Natural flavoring
- Nougat
Egg white intolerance
Egg whites, which are potent histamineHistamine
Histamine is an organic nitrogen compound involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. Histamine triggers the inflammatory response. As part of an immune response to foreign pathogens, histamine is produced by...
liberators, also provoke a nonallergic response in some people. In this situation, proteins in egg white directly trigger the release of histamine from mast cell
Mast cell
A mast cell is a resident cell of several types of tissues and contains many granules rich in histamine and heparin...
s on contact. Because this mechanism is classified as a pharmacological reaction, or "pseudoallergy
Pseudoallergy
A pseudoallergy is a condition named for its similar presentation to a true allergy, though due to different causes.It may be due to alterations in the metabolism of histamine.It can be the cause of some forms of food intolerance....
", the condition is considered a food intolerance
Food intolerance
Food intolerance or non-allergic food hypersensitivity is a term used widely for varied physiological responses associated with a particular food, or compound found in a range of foods....
instead of a true IgE-based allergic reaction.
The response is usually localized, typically in the gastrointestinal tract. Symptoms may include abdominal pain, diarrhea, or any symptoms of histamine release. It can result in an anaphylactoid reaction, which is clinically indistinguishable from true anaphylaxis
Anaphylaxis
Anaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
, if sufficiently strong.
Some people with this condition tolerate small quantities of egg whites. They are more often able to tolerate well-cooked eggs, such as found in cake or dried egg-based pasta, than loosely cooked eggs, such as fried eggs or meringues, or uncooked eggs.
Notable people allergic to eggs
Famous people allergic to eggs include:- Elizabeth Bird, wife of Alfred BirdAlfred BirdAlfred Bird was a British food manufacturer and chemist. He was born in Nympsfield, Gloucestershire, England in 1811 was the inventor of a series of food products mostly now taken for granted...
, who invented the famous egg-free Bird's CustardBird's CustardBird's Custard is the original version of what is known generically as custard powder. It is a cornflour -based powder which thickens to form a custard-like sauce when mixed with milk and heated to a sufficient temperature...
, the original version of what is known generically as custard powder today. - NFL player Drew BreesDrew BreesDrew Christopher Brees is a quarterback for the New Orleans Saints of the National Football League. He was drafted by the San Diego Chargers in the second round of the 2001 NFL Draft. He played college football at Purdue....
See also
- AllergyAllergyAn Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...
- List of allergies
- AnaphylaxisAnaphylaxisAnaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
- AsthmaAsthmaAsthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
- Dairy productDairy productDairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...
- LysozymeLysozymeLysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, are glycoside hydrolases, enzymes that damage bacterial cell walls by catalyzing hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between...