Pilot Study Successful in Taming Allergic Reactions to Food
DURHAM, N.C. -- Children who were allergic to eggs were able
to essentially overcome their allergy by gradually consuming
increased quantities of eggs over time, researchers at Duke
University Medical Center and the University of Arkansas for
Medical Sciences have found in a small pilot study.
"Participants who took a daily dose of egg product over the
two-year study period were able to build up their bodies'
resistance to the point where most of them could eat two
scrambled eggs without a reaction," said A. Wesley Burks, M.D.,
chief of Duke's Division of Allergy and Immunology and a senior
member of the research team. "Egg allergies cause a significant
decrease in quality of life for many people, so this study is
exciting in that it brings us a step closer to being able to
offer a meaningful therapy for these people."
Egg allergy is one of the most common food allergies among
children in the United States, Burks said. Just how many
children are allergic to eggs is unclear, but the National
Institute of Allergy and Infectious Diseases estimates that 6
percent to 8 percent of children have some type of food
allergy. Most children outgrow egg allergy by age 5, but some
people remain allergic for a lifetime.
The findings are reported in an advance online edition of
the Journal of Allergy and Clinical Immunology and will appear
in the journal's January 2007 print edition.
The study was funded by the National Institutes of Health
and the two universities.
The study is the first in a series of studies on food
allergy "desensitization" that are under way at Duke and the
University of Arkansas. The goal, Burks said, is to offer food
allergy sufferers protection from accidental ingestion of items
that provoke reactions and, eventually, to induce complete or
near-complete tolerance to those items.
Burks and his colleagues modeled the study on a commonly
used method for treating seasonal allergy sufferers to
alleviate symptoms. In this approach, called immunotherapy,
physicians give patients shots containing small amounts of the
troublesome allergen in an effort to build their tolerance to
it. The therapy works on a cellular level to alter specific
immune system cells, called lymphocytes, that play a part in
orchestrating allergic reactions and to increase the immune
system's production of antibodies that attack and neutralize
allergens, Burks said.
The seven subjects in the study, who ranged from 1 to 7
years of age, had a history of allergic reactions, including
hives, wheezing and vomiting, when they consumed eggs or egg
products. For safety's sake, none of the children enrolled had
previously experienced a life-threatening allergic reaction,
Burks said. As an extra precaution, the subjects received a
supply of epinephrine, which is commonly used to treat
breathing problems that can occur with food allergy.
Instead of receiving shots, as seasonal allergy sufferers
do, the subjects were given small doses of powdered egg orally,
mixed in food. "We started the subjects with a very small
concentration of egg product -- the equivalent of less than
one-thousandth of an egg -- and then we increased the dose
every 30 minutes for eight hours in order to determine the
highest dose that each subject could tolerate," Burks said.
The subjects consumed the first doses in the study clinic.
The researchers then gave the children's parents or caregivers
a supply of egg product, allocated into the tolerated doses,
which the subjects consumed daily at home, mixed with other
The children returned to the clinic every two weeks. At each
visit, the researchers increased the subjects' dosages until
they reached the equivalent of one-tenth of an egg, Burks said.
The children then continued to take this "maintenance dose"
daily for the duration of the study.
Over time, the children showed both an increase in tolerance
to eggs and a decrease in the severity of their allergic
reactions, Burks said. At the end of the study period, most of
the children could tolerate two scrambled eggs with no adverse
The researchers now are conducting two follow-up food
allergy desensitization studies, Burks said. In one study,
subjects receive higher doses of egg to see if this will
further reduce their sensitivity or even neutralize the allergy
The second study focuses on children who are allergic to
peanuts, to see if the desensitization approach can build their
tolerance and decrease the severity of their reactions. Peanut
allergy, which can be life-threatening, affects approximately 1
percent of children under age 5, and its incidence has been on
the rise over the past 15 years, according to Burks. Studies
have shown that about 20 percent of children with egg or milk
allergy will go on to develop a peanut allergy.
Other members of the research team were Ariana Buchanan,
Todd Green, Pamela Steele, Laurent Pons and Laurie Lee of Duke
and Amy Scurlock, Lynn Christie, Karen Althage and Rick Helm of
the University of Arkansas.