BACKGROUND: Eggs are the most common food allergy in children. Egg allergy can occur at infancy. Most children outgrow their egg allergy before they hit adolescence, but in some instances it can continue into adulthood. Egg allergy symptoms will usually occur a few minutes to a few hours after eating eggs or foods containing eggs. Symptoms can be mild to severe and include: hives, skin rashes, nasal inflammation, and vomiting or other digestive problems. Egg allergy can also cause a life-threatening reaction called anaphylaxis, although it is very rare. (Source: www.mayoclinic.com)
CAUSES: All food allergies are caused by an immune system overreaction. The immune system mistakes certain egg proteins as harmful. Whenever someone comes in contact with egg proteins, immune system cells recognize them and signal the immune system to release histamine and chemicals that cause allergic symptoms and signs. Egg yolks and egg whites can both cause allergies, but allergy to egg whites is the most common. (Source: www.mayoclinic.com)
HIDDEN SOURCES OF EGG PRODUCTS: Even if a food is labeled egg-free it still could contain some allergy causing egg proteins. Foods that contain eggs can include: marshmallows, mayonnaise, meringue, sauces, frostings, processed meat (like meatballs and meatloaf), pudding, salad dressing, pastas, root beer, and some alcoholic drinks. Nonfood products that contain egg products can include: medications, shampoos, cosmetics, and finger paints. (Source: www.mayoclinic.com)
NEW TECHNOLOGY: The study at the University of North Carolina School of Medicine found that by eating small amounts of egg every day for many months lowered the number of allergic reactions in 75 percent of egg-allergic children; 28 percent were able to incorporate egg into their regular diets after two years on the treatment. The intent of the study was to develop a new treatment for egg allergy since the only option so far has been to avoid eggs altogether. The study enrolled 55 children and adolescents between the ages of five and eighteen who had egg allergies. Participants were given small amounts of powdered egg or a placebo to mix into food, eventually building up to the equivalent of a third of an egg. Children on the treatment did experience allergic reactions to the egg powder during the first couple of months of the study, but none had a severe reaction. At the 10 month mark, researchers administered an “oral food challenge” to test the study participants’ reactions to eating 5 grams of egg powder, which is equivalent to an entire egg. Fifty-five percent of participants on the treatment passed the challenge without significant allergic symptoms. None of the participants on the placebo passed the challenge. Researchers gave another challenge after 22 total months on the treatment. They were given 10 grams of egg powder, which is equal to nearly two eggs. Seventy-five percent passed the challenge. Those who passed stopped doing the treatment. After two years, those who had discontinued the second challenge were administered a final test. They were given 10 grams of egg powder and one cooked egg; 28 percent of the original treatment group passed and were able to integrate eggs into their lives. Dr. Wesley Burks says, “Now, at the end of the third year of treatment it was 45 percent that were able to come off the food and incorporate egg into their diet.” Researchers believe that the study brings hope for treating egg and possibly other food allergies, but further research will be needed. (Source: www.unchealthcare.org)
Wesley Burks, MD, Chair of the Department of Pediatrics, Physician, and Chief at North Carolina Children’s Hospital, talks about a new study that could mean the end for egg allergies.
Doctor if you could, tell us a little bit about this study. Why did you choose to do a study on egg allergies?
Dr. Burks: We know that about 15 million people in the U.S. have food allergy; of that 15 million about 4 million of them are kids. The three foods that cause most allergic reactions are milk, egg, and peanuts. One of the most problematic, accidental reactions are from eggs and that is why we chose an older group of kids that were not going to outgrow their egg allergy to see if we can make it go away.
What are some of the symptoms that go along with egg allergies that make it dangerous?
Dr. Burks: The symptoms of any food allergy are related to the skin, the respiratory tract, and the GI tract. Skin symptoms include hives or whelps and can be an itchy, red rash. Respiratory symptoms are coughing, wheezing, or swelling of the throat. The GI symptoms include vomiting; sometimes maybe severe abdominal pain or diarrhea.
How long does the symptoms last?
Dr. Burks: After a child accidentally ingested an egg, literally within seconds to minutes or at the most within 2 hours, they will begin to have symptoms. It may be just skin or it may be skin, respiratory, and GI. The symptoms typically last somewhere between 2 and 4 hours. They will not go on into the next day because the body begins to get rid of the foreign antigen. That is what that allergic reaction does; it helps get rid of the food.
It is hard to avoid eggs, because it is in everything we eat almost. What are some of the treatments, if any, for egg allergies at this point?
Dr. Burks: Right now, the best treatment is an appropriate diagnosis to help the child and family know that they are truly allergic to egg and not allergic to other things. Then, we help them avoid it. There is no proactive treatment and that is the reason this study was done, to develop an active treatment.
Can you explain the process of the study?
Dr. Burks: These are children older than 5 years of age who had had long-standing egg allergy. We did not expect them to, based on this criteria, outgrow their egg allergy anytime during the study for the next 3 years. As we entered the blinded study, several centers were involved through the Consortium of Food Allergy Research; 40 children received treatment and 15 received placebo. The paradigm of treatment is starting out at a very low dose and building up to a daily dose, but receiving a new dose about every 2 weeks. It took about 4 or 5 months.
What did you see in the kids with the small doses? Was there any reaction at all during the process? I noticed after it said 10 months that it lowered the threshold for the allergic reaction, but did they have any symptoms on a day-to-day basis?
Dr. Burks: For the daily dosing, you basically take an egg white powder and mix it in food. Less than 10% of the kids had local side effects to actually taking the treatment. A few had to drop out, but that was a really small number. So, we were able to build each child up to a specific dose and then at the end of the 10 months, we did a food challenge to find out how much egg they would tolerate while they were on treatment.
How did that go?
Dr. Burks: We saw that out of the group that was treated, of those 40, over half of them were able to tolerate the whole challenge that we did with the egg. None of those in the placebo group were able to tolerate the challenge. So, there was a significant difference in those on treatments and to those not on treatments.
Then you used another food challenge after 22 months. Is that correct?
Dr. Burks: The study design was that those that were already on treatment, those 40 for the first year, continued on treatment for a second year. Those that were on a placebo, we just observed until that second year. At the end of the second year we did another challenge. Now, 75% of them tolerated that challenge.