Taking allergy drops instead of enduring
painful shots may someday become an option for people who are allergic to
In a preliminary study, Italian researchers found that putting honeybee
venom under the tongue was safe and significantly reduced reactions in people
allergic to bee stings .
Immunotherapy using the ubiquitous allergy shot is the standard treatment
for allergies to everything from
insect stings to dust mites. Tiny amounts of the allergens are injected into
the patient until tolerance develops.
The new study involved a different form of immunotherapy, called sublingual
immunotherapy. It involves putting extracts of allergens under the tongue. Like
the shots, sublingual immunotherapy reduces allergic sensitivity in many
patients over time.
Although a popular treatment for asthma , rubber
latex, and other allergies in many European countries, sublingual therapy has
not been approved for use in the U.S.
And it's never been used to treat sting allergies, even in Europe, says
researcher Giovanni Passalacqua, MD, of the Allergy and Respiratory Diseases
Clinic at the University of Genoa.
Honeybee Venom Drops vs. Placebo
The new study, presented here at the annual meeting of the American Academy
of Allergy, Asthma and Immunotherapy (AAAAI), is the first attempt to determine
if sublingual immunotherapy is effective against honeybee sting allergies,
The study involved 30 people with a history of local allergic reactions to
honeybee stings. A local reaction is a large raised patch of pricked skin right
in the area of the sting. These raised bumps are often called wheals.
The participants were randomly assigned to receive either sublingual
immunotherapy in the form of honeybee venom drops placed under the tongue, or
Patients in the immunotherapy group got escalating doses of honeybee venom
for six weeks, followed by a maintenance dose, given three times a week for six
"You hold the drop under the tongue for about one or two minutes, then
swallow," Passalacqua says.
The Bee Sting Challenge
Then came the bee sting challenge. "We put insects in a jar and then put
the jar on the patient's forearm" and looked to see what happened, he
It worked. The median diameter of the sting wheals in patients given
sublingual immunotherapy dropped from about 8 to 3 inches. Looked at another
way, wheal diameter was reduced by more than 50% in more than half of them.
"This was a very apparent and very significant reduction in the size of
the reaction to the sting," Passalacqua says.
In contrast, there was no change in wheal diameter in the placebo group, and
one person broke out in hives .
The findings show that sublingual immunotherapy against honeybee stings
works, Passalacqua says.
Venom Shots Are Effective
The next step: Testing sublingual immunotherapy in patients who have more
severe allergic reactions that spread far from the sting or that affect the
entire body. Doctors call these systemic reactions; while uncommon, they can be
Clifford Bassett, MD, vice chair of AAAAI's public education committee and
an allergist at Long Island College Hospital in Brooklyn, N.Y., says that if
sublingual immunotherapy proves safe and effective in larger numbers of people,
"it will offer an alternative treatment for our patients. It's always good
to have multiple choices."
In the meantime, he tells WebMD, venom shots are more than 95% effective in
reducing the risk of systemic reactions in people with honeybee sting
While not always possible, avoiding the bees in the first place is the first
line of defense, Bassett adds. A few tips: avoid cologne and trash-collection
areas where the insects congregate.
By Charlene Laino
Reviewed by Louise Chang
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