By Amelia Murphy
November 14, 2014
Food allergies are on the rise, making school, traveling, and even birthday parties risky business for many children. It’s hard to tell if children’s increased sensitivity to certain foods is due to their hyper-clean environments,1 early exposure to antibiotics,2 too little vitamin D from the sun,3 or something else. As of 2011, 1 in 13 children have a food allergy in the United States, and 40% of those children have had a severe or life-threatening reaction.4
What is a Food Allergy?
A food allergy is when a body’s immune system mistakes a certain food for something harmful, which leads to a potentially dangerous reaction. For example, if a person allergic to peanuts eats a peanut, her immune system overreacts and releases a chemical called histamine, which can affect the “skin, eyes, nose, airways, intestinal tract, lungs, and blood vessels.”5 This can lead to itchy eyes, wheezing, hives, itchy mouth, or a tight throat, among other things. In the worst case scenario, the allergic person may enter a state of anaphylaxis, a severe whole-body allergic reaction, which may include difficulty breathing, vomiting, swelling of parts of the body, and even death.
Anything that produces an allergic reaction in many people is called an “allergen.” Peanuts are one of the most common food allergens. Milk, eggs, fish, crustacean shellfish, wheat, soy, peanuts, and tree nuts make up 90% of the food allergens in the United States.6
Most doctors advise children and their parents to: 1) prevent a reaction by having the allergic child or adult completely avoid the food allergen;7 and 2) carry or have quick access to an EpiPen at all times in case the person is accidentally exposed and has anaphylaxis. But avoidance of problem foods isn’t always easy, for children or adults. Peanuts can be hidden in a variety of foods, such as specialty pizzas, some enchilada sauces, egg rolls, glazes, marinades, chili sauce, and candy.8 Knowing that a life-threatening allergic reaction may be one bite away is frightening for children, parents, and other adults.
Can allergic reactions to food be prevented by oral immunotherapy?
Oral immunotherapy (OIT) involves training children allergic to peanuts to do what they have been trained not to do: eat peanuts! In a 2014 study of this treatment, over 80% of participants were able to eat the equivalent of about five peanuts after OIT.9 This form of treatment has the potential to make the daily lives of young peanut allergy sufferers and their parents much less stressful.
The publicly funded study, which was published in the respected medical journal The Lancet in April 2014, found that introducing peanut protein powder to children in small but increasing doses can train the body to be less sensitive over time. The year-long study included 99 children from the United Kingdom, aged 7-16, with peanut allergies. During the first 26 weeks of the study, one group of children received peanut protein powder every day (the treatment group) and the other group did not receive the powder or any other exposure to peanuts (the control group). In the second 26 weeks of the study, only the control group took the peanut protein powder.
After each of the two 26-week periods, all the participants were given a dessert to eat that either had peanuts or did not. Neither the researchers nor the children knew who was getting which dessert. At the end of the first 26 weeks, 84% of the children who received the peanut powder treatment could tolerate the equivalent of 5 peanuts daily. Close to two-thirds of the children in the treatment group had no reaction to the dessert at all (which contained 10 peanuts). While 38% of the children receiving the treatment had some sort of reaction to the dessert, 100% of the control group had an allergic reaction to it.
During the second 26 week period, the children in the control group received the peanut powder treatment instead. By the end, 91% of them were able to tolerate the equivalent of 5 peanuts a day. A little over half (54%) ate their dessert containing the equivalent of 10 peanuts without experiencing any reaction. The researchers concluded that the majority of the children had mild or no allergic reactions to a dessert with peanuts after the treatment.
Why is this study important?
This is the largest randomized controlled study ever done on oral immunotherapy for children with peanut allergies. Earlier studies were conducted on smaller numbers of children and did not compare those getting treatment to those who didn’t. This 2014 study will pave the way for future research needed to answer many still unanswered questions, such as how long does the desensitization last, how well does it work on adults, and could this be used for other food allergies?
What are the drawbacks of this study?
One of the problems with this study is that 15 of the 99 participants dropped out without completing the study and were not included in the analysis. Most of the children who quit did so because they were experiencing unpleasant allergic reactions, didn’t like the taste of the powder, or were unable to increase their dose enough to take the dessert challenge. By excluding these children (who were mainly in the treatment group), the researchers may have made OIT look a little more successful than it was. On the other hand, nearly all of the controls who received the peanut powder completed the study and achieved the same high level of desensitization as the treatment group. What is clear from this study is that not everyone will be willing or able to undergo this form of allergy treatment.
Another shortcoming of the study was that it did not continue to follow-up with the children after the therapy was over. The effects of OIT wear off over time, and it is expected that many will become allergic again after about 9 months if they don’t have a fixed daily dosage of peanuts.10 The researchers suggest continuing to consume peanut powder every day for several years after treatment, but since that was not studied, there is no way to know. Some treatment centers that offer OIT instruct patients to eat 3 peanuts a day after OIT in order to stay desensitized, but this is not based on research but rather scientific guesswork.
The 2014 study does not tell us whether OIT can work for people younger than 7 or older than 16. While allergies to milk11, eggs12, and wheat13 often end up being childhood allergies that lessen or go away completely by the teenage years, allergies to peanuts, tree nuts, fish, and shellfish tend to be lifelong. Further research is needed to study the impact of this therapy for other food allergies and for adults.
Is OIT expensive?
Although OIT is still considered an experimental treatment, many health insurance companies will pay for it. Prices vary from one center to another, but the OIT Center in Michigan, for instance, charges about $140 per hour on the first visit, which can take up to 8 hours. Visits to increase dosage are about $110 per visit (with at least one week between dose increases) for about four months. Other centers have patients undergo OIT for longer. In other words, the cost is likely to be several thousand dollars.
If OIT is found to work over the long-term, it could mean less reliance on EpiPens, fewer trips to the ER, less worry and greater shared enjoyment for all. This is exciting news but remember: OIT should NOT be tried at home, without a doctor’s supervision!
There are centers around the country that are beginning to offer OIT, with treatment lasting from 6 to 12 months. However, many parents will be reluctant to try OIT for their children and insurance companies may be reluctant to pay for it until more is known about how long OIT should last, what a maintenance dose should be, and how long maintenance therapy is needed. Likewise, more research is needed before OIT can be considered promising for adults or for other food allergies.