Egg Allergy

Julie Metos, MPH, RD, CDE

What Is an Egg Allergy?
 Food allergies occur when a person's immune system mistakenly believes that something he or she ate is harmful to the body. In an attempt to protect the body, the immune system produces antibodies, called immunoglobulin E (IgE), to that food. Those antibodies then cause mast cells (allergy cells in the body) to release chemicals, one of which is histamine, into the bloodstream. The histamine then acts on a person's eyes, nose, throat, lungs, skin, or gastrointestinal tract and causes the symptoms of the allergic reaction. Future exposure to that same allergen (things like eggs or nuts or pollen that you can be allergic to are known as allergens) will trigger this antibody response again. This means that every time that person eats that particular food, he or she will have an allergic reaction.
An egg allergy usually begins when children are very young, but most outgrow the allergy by age 5. Most children with an egg allergy are allergic to the proteins in egg whites, but some can't tolerate proteins in the yolk. Egg white powder, used in cooking and in baked goods, can also be dangerous to those who have a severe egg allergy.
Signs and Symptoms
People who are allergic to eggs may feel sick just a few minutes after consuming egg proteins or up to a couple of hours later. Most reactions last less than a day and may affect any of three body systems:
the skin – in the form of red, itchy, bumpy rashes (hives) or eczema
the gastrointestinal tract – in the form of stomach cramps, diarrhea, nausea, or vomiting
the respiratory tract – symptoms can range from a runny nose and sneezing to the triggering of asthma with coughing and wheezing
People who have a serious egg allergy may experience anaphylaxis – a severe allergic reaction that causes swelling of the mouth, throat, and airways leading to the lungs, resulting in an inability to breathe. In addition, anaphylaxis causes a dangerous drop in blood pressure, which can make someone dizzy or pass out, and may quickly lead to shock. For people who are especially sensitive to eggs, even egg fumes or getting egg on the skin can cause an anaphylactic reaction, so eggs should be kept out of the home completely.
Diagnosing an Egg Allergy
There are no foolproof tests for an egg allergy. Diagnosis is done through a process of elimination, in which avoidance of any foods made with eggs is crucial. If a child has the same reaction every time he or she eats eggs, diagnosis may be simple. But most egg-allergic people react to egg proteins within other foods, making the diagnosis more complicated.
For an accurate diagnosis, an experienced doctor or allergy specialist should be consulted. He or she will perform a physical exam and will ask you and your child questions, such as how often does your child have the reaction, how quickly do symptoms start after eating a particular food, and whether any family members have allergies or conditions like eczema and asthma.
If the doctor suspects an egg allergy he or she will probably perform skin testing, in which a diluted extract of egg is placed on the forearm or back and the skin is scratched or pricked with a needle. If swelling or redness occurs, this is considered an allergic reaction.
It's important that your child stop taking antiallergy medications (such as over-the-counter antihistamines) 2 to 3 days before a skin test because they can interfere with the results. Most cold medications, as well as some antidepressants, can also affect skin testing. Check with the allergist's office if you're unsure about what medications need to be stopped and for how long.
Some doctors may also take a blood sample and send it to a lab where it will be mixed with some of the suspected allergen and checked for IgE antibodies. You may hear a doctor refer to this type of test as a RAST test (or radioallergosorbent test).
Doctors may also use an elimination diet, during which the eggs and egg products are completely removed from the child's diet for 1 to 2 weeks. If the symptoms go away, a diagnosis of egg allergy can be presumed, especially if symptoms recur upon reintroduction of eggs into the diet. It's important to note that an elimination diet must be strictly monitored and followed if the egg allergy is to be identified.
If the results of these tests are still unclear, then in select cases a food challenge may be needed for final diagnosis. For this test, your child might be given gradually increasing amounts of eggs to eat while being watched by the doctor for symptoms. This type of test can only be performed in a clinic or hospital where access to immediate medical care and medications is available, and it should be avoided if your child has experienced an anaphylactic reaction to eggs in the past.
Treating an Egg Allergy
There's no easy way around it – the only way to treat an egg allergy is to eliminate eggs and foods made with eggs from the child's diet. This can be challenging because so many foods are made with eggs and egg derivatives. If your child has an egg allergy, you'll need to read ingredient lists carefully, and everything your child eats must pass the no-eggs test.
No medication can prevent an allergic reaction to eggs. If a child does ingest egg products and has an allergic reaction, antihistamines may relieve gastrointestinal symptoms, hives, sneezing, or runny nose.
Anaphylactic reactions can be fatal even if they begin mildly. Because reactions can be severe, parents and caregivers must know how to protect children from eating foods that contain eggs, as well as what to do if the child does eat something that can cause an allergic reaction.
In case of an emergency, doctors recommend that children 12 or 13 and older (depending on the maturity of the child) with a severe egg allergy or their parents keep a shot of epinephrine with them in an easy-to-carry container that looks like a pen (this device is also called an EpiPen). Millions of parents across the country carry an EpiPen (for kids 66 pounds, or 30 kilograms and over) or EpiPen Jr. (for kids between 33 and 66 pounds, or 15 and 30 kilograms) everywhere they go. EpiPen is only available with a prescription.
With one injection into the thigh, EpiPen administers epinephrine, or adrenaline, to ease the allergic reaction. Your child's doctor can give you instructions on how to use and store the epinephrine injection pen; it's essential that you familiarize yourself with the procedure. You should also be sure to check the expiration date regularly to make sure the pen hasn't expired.
If a doctor has said your child is mature enough to carry the EpiPen, make sure your child keeps the pen readily available at all times. If the child is younger than 12, talk to the school nurse, your child's teacher, and your child-care provider about keeping one on hand in case of an emergency. Also make sure that epinephrine pens are available at your home, as well as at the homes of friends and family members. Your child's doctor may also encourage your child to wear a medical alert bracelet. It's also a good idea to carry an over-the-counter antihistamine, which can help alleviate allergy symptoms in some people. But antihistamines should be used in addition to the EpiPen and not as a replacement for the shot.
Kids who have had to take an epinephrine shot should be taken immediately to a medical facility or hospital emergency room, where additional treatment can be given if needed. Up to one third of anaphylactic reactions can have a second wave of symptoms several hours following the initial attack, so the child might need to be observed in a clinic or hospital for 4 to 8 hours following the reaction.
Caring for Your Child
You may be concerned about your egg-allergic child receiving flu and measles/mumps/rubella (MMR) vaccines, which are grown in cultures from egg cells and may contain a small amount of egg protein. Significant evidence by the American Academy of Pediatrics (AAP) and Centers for Disease Control (CDC) indicates that the MMR vaccine is safe for children who are allergic to eggs. However, you should ask your child's doctor or allergy specialist about getting a flu shot, especially if your child has had a severe allergic reaction to eggs.
When it comes to feeding your child, the solutions aren't as clear-cut. It should come as no surprise that baked goods, baking mixes, cereals, cookies, custards, and ice cream are made with eggs, but candies, hot dogs, meatballs, fast foods, and salad dressings can include egg derivatives as well. Look for – and avoid – these egg products on labels: dried egg, egg white, egg white solids, egg yolk, egg solids, powdered egg, egg substitutes, and whole egg.
There are many products and food ingredients that contain egg products, but whose names don't always include the word egg, such as albumin and ingredients that begin with the prefix "ovo." To ensure that your child isn't eating any food with egg products in it, read and acquaint yourself with all of the ingredients and egg products that should be avoided. By 2006, food makers are required to clearly state on the food label – in or adjacent to the ingredients list – whehter the food contains egg or egg products. Keep in mind though, the new law only applies to foods packaged after 2006. So there may be products still on the store shelves that were labeled before then, and don't have information about the allergen.
Because otherwise nutritious foods may have to be eliminated, it's important to ensure that an egg-allergic child's diet is well balanced. A pediatric registered dietitian can make sure all required nutrients are provided in the food the child is able to eat.