Nov. 28, 2006 -- Children with food allergies are told to avoid problem foods at all costs, but a novel experimental treatment is taking the opposite approach.
In a two-year pilot study conducted by researchers at Duke University and the University of Arkansas, eggs were very gradually introduced into the diets of kids who were highly allergic to them in an effort to desensitize the children.
A similar study is under way involving children with peanut allergies, which more often trigger potentially life-threatening allergic reactions.
Early findings suggest that this gradual challenge approach increases tolerance to problem foods, senior researcher A. Wesley Burks, MD, tells WebMD. Burks is a professor of pediatrics at Duke University Medical Center.
Researchers hope desensitization will help protect food allergy suffers from serious reactions brought on by accidental ingestion of problem foods.
It may even cure people of their food allergies, although it is too soon to tell, Burks adds.
In the peanut study (currently unpublished), children were initially given the equivalent of 1/3,000 of a peanut. Most were eating a peanut a day within six months with little reaction.
"Some children who had allergic reactions to literally a thousandth of a peanut at the beginning of the study had no reaction later on when challenged with 15 peanuts," says Burks.
Don't Try This at Home
While very promising, the desensitization approach to treating food allergies is also highly experimental and should never be attempted without close medical supervision.
Children in the egg and peanut trials were watched closely, and many did experience mild allergic reactions to the food challenges early on, Burks says.
"This is definitely not something that would be safe to try at home without medical supervision," he warns.
A detailed analysis of the experiences of seven children participating in the egg trial was published online last week in the Journal of Allergy and Clinical Immunology.
None of the children had experienced a previous life-threatening allergic (or anaphylactic) reaction, but their parents received the emergency treatment epinephrine to keep on hand as a precaution.
Previous attempts to immunize against food allergies by giving shots containing allergens have been unsuccessful.
So the researchers gave the egg orally, in the form of powdered egg mixed in food.
The first dose was the equivalent of less than one-thousandth of an egg, followed by very small increases given in a clinic in order to determine each child's tolerance.
Then dosages were gradually increased to a maintenance treatment of about one-tenth of an egg daily, which the children continued to receive for the length of the study.
Over time, the children showed an increase in tolerance to eggs and a decrease in the severity of their allergic reactions, Burks says.
At the end of the two-year study, most of the children could tolerate two scrambled eggs with no adverse reactions.
12 Million Allergic Americans
As many as 12 million Americans have food allergies, says Ann Munoz-Furlong, chief executive officer and founder of The Food Allergy and Anaphylaxis Network. Roughly 8% of children under the age of 3 are allergic to some food, she says.
Most children outgrow their food allergies, but there is currently no way to tell which ones will and which ones won't, she tells WebMD.
"That is just one of the things we don't know," she says. "We don't know why one twin might have a food allergy while the other doesn't; and we can't predict who will have [life-threatening] anaphylactic reactions."
Munoz-Furlong says the food challenge seems to be succeeding where shots failed in desensitizing the body to allergic foods.
"This is by far the most exciting research we have seen for food allergies, and we will continue watching it very carefully," she says. "It is a fairly low-tech approach that looks promising."
Until better treatments are available, Munoz-Furlong says everyone needs to be sensitive to the impact of food allergies, even if they are not personally touched by them.
She adds that the holidays can be an especially difficult time for food allergy sufferers and their families because problem foods are often hidden in baked goods or other party foods.
Just a few foods are involved in nine out of 10 allergic reactions: milk, eggs, peanuts, tree nuts, fish, shellfish, wheat, and soy.
"If you don't have a food allergy, be mindful that someone you know might," Munoz-Furlong says.
"Crushed nuts in a piecrust might be difficult to spot, and it could cause a reaction," she says. "Make sure to let people know."