March 19, 2008 (Philadelphia) -- Shots may be fun when you're at your local bar, but for too many allergy sufferers, they're a pesky, even painful, part of ragweed season. Now, researchers report early success testing an under-the-tongue alternative to injections in people with ragweed allergies.
The new treatment is called sublingual immunotherapy, a big term for putting tiny extracts of allergens, in this case ragweed allergens, under the tongue until tolerance develops.
As its name implies, it's a type of immunotherapy, whose most common form is the ubiquitous allergy shot. The injections are the only treatment that's been proven to modify the natural course of the allergic disease, by reducing allergic sensitivity over time.
They might work, "but a lot of people refuse shots for a lot of reasons," says Robert Esch, executive vice president of research and development at Greer Laboratories in Lenoir, N.C., which is developing the treatment.
That makes new options desperately needed, he tells WebMD.
Needs for Antihistamines Cut
The new study, presented here at the American Academy of Allergy, Asthma & Immunology annual meeting, is the first to test sublingual immunotherapy for ragweed allergy in the U.S.
The study involved people with hay fever brought on by a ragweed pollen allergy. They were randomly assigned to receive one of two doses of ragweed allergen extract, administered by a pump placed under the tongue, or placebo.
"You hold it under the tongue for at least one minute, then swallow," Esch says. This is done once a day, in the morning, beginning 8 to 10 weeks before ragweed pollen season and then continuing for another eight to 10 weeks after it starts.
The higher dose cut the need to reach for antihistamine drops, sprays, or capsules during ragweed season by more than 90%.
There was also a 75% reduction in antihistamine use in the low-dose group as well as a 50% to 80% reduction in allergic symptoms in the low-dose and high-dose groups respectively, but these findings could have been due to chance. Esch says that's because not enough people were studied; a larger study is now enrolling patients.
Ragweed Extract Safe
The treatment was very safe and overall, the rate of side effects did not differ between the treatment and placebo groups.
Immune system changes from the start to the end of the study showed growing tolerance to the ragweed allergen in the group that got the active treatment. There was no change in the placebo group.
Andy Nish, MD, of the Allergy and Asthma Care Center in Gainesville, Ga., says although the results are preliminary, the approach "is promising."
Nish notes that sublingual immunotherapy is already a popular treatment for asthma, rubber latex, and other allergies in many European countries. However, it has not been approved for use in the U.S. and "to my knowledge, insurance companies don't cover it," he says.
One potential advantage to shots is that you can desensitize a patient to many allergens at once, Nish tells WebMD.
"With injections, you can pretty much cover the waterfront. If a person is allergic to 10 different things, you can include all the allergens [in the same preparation]. I'm not sure that sublingual therapy works that way," he says.