Oral Immunotherapy - New Hope for Severe Food Allergies

Have you ever seen this phrase on the label of a food product? Perhaps you've wondered why it was there, or why it was so important. If you're one of the 1.5 million Americans with a peanut allergy, you not only knew why it was there, you were grateful - because that one little phrase could save your life.

The word "allergy" may trigger thoughts of sniffling, sneezing, and runny noses, or maybe an itchy rash. But that's the usual reaction to certain plants (like ragweed) or animals (like cats). Food allergies can be much more dangerous. The most severe reactions can include closure of the person's airway, which can be life-threatening. And peanut allergies are the worst of all.

This is a big enough problem for adults. But for children, who may not always know what's safe to eat, it can be very restrictive - for both them and their parents.

Many non-food allergies respond to immunotherapy - immune therapy - in which the person is given injections of very small amounts of the allergen (the substance they're allergic to). This encourages their body to build up a tolerance to that substance. But traditional injections are too strong for people with food allergies. Now a physician at Duke University Medical Center is trying another approach - immunotherapy that can eaten.

This research works with children who are severely allergic to either peanuts or eggs. At the beginning of the study the children were given extremely low doses of either peanut flour or egg powder. "Extremely low" is the key here; the flour contained 1/3000 of one peanut, and the egg powder contained 1/1000 of an egg.

The children were under very close medical supervision during this time. If a child did not react to the initial dose of the allergen, it was gradually increased until there was a small reaction. Then a dose just below this level was given to the parents and the child was sent home. They took this dose once a day for two weeks, after which a stronger dose was prescribed. This procedure was then repeated for as long it was safe.

The results of the study have so far been very encouraging. Some of the children increased their tolerance levels to the point where they were able to eat as many as 15 peanuts without an allergic reaction. This might not sound like much, but for a child who previously had not been able to eat even a piece of one peanut without having trouble breathing, it was a major milestone. And some of the children with the egg allergies fared even better. They were able to eat two whole eggs without reacting.

This is not the first use of oral immunotherapy. It's actually been studied for the past five years using people (mainly adults) with non-food allergies, and has proven to be fairly successful. It's especially useful when the allergen is hard to avoid, or when traditional allergy medications don't work or have serious side effects. It's also more convenient because, unlike injections, it can be administered at home, by the patient or a caregiver.

Physicians do stress the importance of not trying oral immunotherapy at home; it's just too dangerous, especially with food allergies. The beginning stages must be handled very carefully, and monitored very closely, by medical professionals.

Some types of oral immunotherapy also take a long time to work; in the case of hay fever treatment, it can be several months before the person notices a change in their tolerance level. The therapy may also need to be continued for several years. The immunotherapy being tried with the children at Duke University is too new for there to be established standards. But there's already a question about whether the children's tolerance would drop back down if they stopped the therapy.

However, the physicians are already impressed with how far some of the children have come in being able to tolerate foods they're allergic to. The parents are happy because they don't have to worry as much about their children when they're away from home. And adults who've had to limit their exposure to common plants, foods, or even pets can live their lives more fully. Immunotherapy holds the promise of freedom for anyone living under the sometimes severe restrictions of a major allergy.