Kids May Learn To Tolerate Food Allergens
SUNDAY, July 5 (HealthDay News) — Doctors have long used allergy
shots to desensitize children and adults to environmental allergens such
as bee stings, pollen, mold and dust mites.
Now researchers are trying to apply that theory to food allergies,
through processes called oral immunotherapy and sublingual
immunotherapy.
They believe they can build up a child's tolerance for a food that
prompts an allergic reaction by exposing the child to tiny amounts of that
food.
“It is something that has been recently put into play,” said Dr.
Michael Pistiner, an allergist in Leominster, Mass., and a spokesman for
the American Academy of Allergy, Asthma & Immunology. “More and more
of these trials have been started. It does seem to be very promising. It's
very exciting.”
Trials involving eggs, peanuts and milk have produced positive results,
said Dr. Scott H. Sicherer, an associate professor of pediatrics at the
Jaffe Food Allergy Institute at the Mount Sinai School of Medicine and
chairman of the allergy and immunology section for the American Academy of
Pediatrics.
“The studies are promising in that some individuals are able to get to
high doses of the food used in treatment,” Sicherer said.
Sublingual immunotherapy works by placing an extract of the food
allergen under the child's tongue. The membranes of the mouth absorb trace
amounts of the allergen, absorbing just enough to desensitize the immune
system without prompting an allergic reaction.
Oral immunotherapy takes it a step further by having children eat tiny
amounts of the allergen. “The approach involves ingesting an extremely
small and then gradually increasing amount of the food under medical
supervision, with the hope of getting to an amount that is not causing
reactions and is more substantial in dose,” Sicherer said.
However, both Sicherer and Pistiner warn that these therapies are still
in the experimental stage, and many questions remain.
“All of the experts working in this treatment currently believe it is
too early to attempt widespread use and that much more needs to be done to
see if this is a viable treatment,” Sicherer said.
For one thing, there's still a risk of severe allergic reaction
prompted by even the tiny amounts used in immunotherapy.
“People have significant reactions trying to do this, including
anaphylaxis, and not all can move ahead with dosing,” Sicherer said.
Researchers also are not sure how deeply ingrained the tolerance
becomes in a child undergoing oral or sublingual immunotherapy.
“Is there ever a time you can stop taking it, or does it only work as
long as you're taking your maintenance dose?” Pistiner asked. “Does it
give you complete ability to eat that food, or does it only help prevent
reactions when trace amounts of the foods are consumed?”
For example, if you're allergic to pine nuts, will immunotherapy allow
you to eat pine nuts as you like, or will it only prevent you from having
an allergic reaction when you eat a food processed on equipment that also
processes pine nuts?
The doctors agree on one other point: This is absolutely not something
a person should try at home.
The amounts of food given allergic children are measured out precisely,
and delivered under the watchful eyes of doctors ready to step in and
treat any side effects or allergic reactions at a moment's notice.
“This is an experimental therapy that should only be undertaken under
the direction of a trained allergist,” Pistiner said. “Doing this at home
is absolutely not safe.”
More information
The U.S. National Institute of Allergy and Infectious Diseases has more
on food allergies.
