Most people who are allergic to peanuts avoid them like the plague. Now a new study suggests that the best way to cure this most common of food allergies may actually be to eat peanuts. But please: don’t try this at home.

Immunologists have long known that exposing people to very small doses of an allergy-provoking substance can desensitize them, creating a state of immune tolerance. The technique is often used for pollen allergies. This is one of the first studies to look at feeding patients an allergy-provoking food.

The study, begun five years ago by researchers at Duke University and Arkansas Children’s Hospital, included 33 children with severe allergies to peanuts. Most couldn’t tolerate as little as one-sixth of a peanut without a reaction. Closely monitoring them, researchers began giving them increasing amounts, starting with as little as one-thousandth of a peanut. Eight to ten months later, many of the kids were eating the equivalent of up to 15 peanuts a day without problems.

Even their immune systems had adapted. Allergies are triggered by an immune substance called immunoglobulin E (IgE). “If you have it you’re likely allergic, if you don’t, you aren’t,” explained Wesley Burks, MD, chief of pediatric allergy and immunology at Duke University. The kids in the study started with IgE levels of more than 25. “At the end of the study, their peanut IgEs were less than 2 and have remained that way since we stopped treatment,” said Dr. Burks.

The results herald good news for the estimated four million Americans with food allergies. An estimated 75 Americans every year die from eating peanuts and an equal number from other food allergies. But if you’re allergic to peanuts, don’t go nuts quite yet. Even the scientists who announced the findings at the American Academy of Asthma and Immunology meeting in Washington, DC, caution that this form of desensitization therapy needs to be tested in follow-up studies before it is used in practice. Their results include only 33 children, they point out, too small a group for researchers to know if the treatment worked or if the children simply outgrew their allergies. And not all of those children stuck with the study protocol.

“In my clinic, I would do the same things I’ve always done,” Dr. Burks said. “Once diagnosed with a food allergy, I would recommend that they avoid the food. We have to wait for studies to show the treatment is safe, and to see desensitization start to work. We also want to know the therapy works long term.”

 © 2009 PDQhealth

Tags: allergy, desensitization, food allergies, peanuts