Progress Against Peanut Allergies
Oral Immunotherapy May Desensitize Allergic Children; Skin Test May Predict Who Will Outgrow
Small doses of peanut protein, given for months under medical supervision,
can desensitize children with peanut allergy, reducing the risk of a reaction
if they accidentally eat peanuts, according to a new study.
In other new research, scientists say they have found a way to predict which
children are likely to outgrow their allergy to peanuts.
Both studies were presented Saturday at the 2007 Annual Meeting of the
American Academy of Allergy, Asthma and Immunology in San Diego.
About Peanut Allergies
Peanut allergies affect about 1% of the U.S. population, according to the
Reactions can range from mild to severe, even leading to anaphylaxis, a
potentially fatal response that can cause breathing problems and loss of
Traditional advice for food allergies was to simply avoid the food.
But avoiding all peanut-containing foods can be difficult and accidental
ingestion often occurs, says Scott David Nash, MD, allergy fellow at Duke
University and an author of the desensitization study.
For years, allergists have used immunotherapy, or allergy shots, to help
children with allergies to insect stings and nasal allergies to non-food
substances, for example.
With immunotherapy, tiny amounts of the allergens are injected until
Oral Peanut Immunotherapy
So Nash's team decided to try oral immunotherapy for peanut allergy
problems, giving eight children with known peanut allergy escalating doses of
peanut protein in the form of a flour mixed into applesauce or other
"We are the first to do a trial of oral immunotherapy for peanut
allergy," he tells WebMD.
The treatment included three phases: one day in the medical center, with
increasing doses given throughout the day; a home phase lasting three or four
months that involved daily, escalating doses; and a home maintenance phase in
which the daily dose was 300 milligrams, about the equivalent of one
The maintenance phase lasted up to 18 months, depending on how much peanut
protein the child tolerated.
At the end of the study, which seven children completed, Nash's team gave
the children a "food challenge" to peanut flour, exposing them to up to
nearly 8 grams, or the equivalent of more than 13 peanuts.
"Most [five of seven] tolerated the equivalent of 13 peanuts at the food
challenge at the end of the study," Nash says.
Immune system changes from the start to the end of the study showed growing
tolerance to the peanut protein, he says.
Goals of Immunotherapy
"What we would like to have happen is for their food allergy to go
away," Nash says.
For now, however, he says, "We have essentially proven they can tolerate
an accidental ingestion. We think our patients now are at reduced risk for