CNN — In Europe, some allergy sufferers are given sublingual immunotherapy, or allergy drops, to treat their symptoms. These tiny drops of purified allergens -- such as pollen or dust mites -- are placed under the tongue as an alternative to weekly allergy shots. The drops work like a vaccine, slowly increasing the body's tolerance to the allergen.
The Food and Drug Administration has yet not approved these drops for use in the United States, but new evidence published this week by the Journal of the American Medical Association could pave the way for American pharmaceutical companies.
"There is a tremendous interest in this treatment," said Dr. Clifford Bassett, medical director of Allergy and Asthma Care of New York. "As such there have been and are currently clinical trials underway by various companies looking to try to get an approval and come to the U.S. market in the years ahead."
Dr. Sandra Lin from the Johns Hopkins University School of Medicine and her colleagues reviewed 63 studies to analyze the effectiveness of allergy drops.
The researchers found strong evidence that the drops improve asthma symptoms, with eight of 13 studies reporting an improvement of more than 40%. They also found moderate evidence that the drops decrease symptoms of allergic rhinitis - symptoms such as a runny nose or congested sinuses that are similar to those caused by the common cold.
In 16 of 41 studies, allergy medication use decreased significantly among participants taking sublingual immunotherapy.
The researchers concluded that these under-the-tongue drops are effective, but that more research is needed to determine the optimal doses.
Up to 40% of Americans suffer from allergic rhinitis or allergic asthma, according to the journal article. Currently patients are administered allergen immunotherapy through skin injections, Bassett said. Allergy drops could be more convenient than these allergy shots, as they could be administered quickly and easily at home.
"I expect this year's pollen season to be among the worst, in part due to higher pollen levels ... maybe made worse by warmer temperatures and climates," Bassett said.
Here are five of his tips for surviving the allergy season:
1) Wear sunglasses to block airborne allergens from entering your eyes.
2) Consider exercising indoors on high-pollen days. More pollen is generally found on warm, dry and windy days.
3) Start early with allergy treatments - many medications work better if you start them before symptoms begin.
4) Shower before going to bed to reduce the number of allergens that are brought into your bedroom.
5) Keep your windows closed and set your air conditioner to "recirculate" to keep out pollen.