(Reuters Health) - Almost three in four U.S. allergy specialists are prescribing tablets to ease symptoms caused by pollen, ragweed and dust at least some of the time, though they have not completely shifted away from allergy shots, a survey suggests.

The upside of allergy shots, available for more than a century, is they can be formulated to treat more than one allergy. But they are not always appealing to patients because they require multiple office visits to administer. Recently-introduced tablets dissolve under the tongue and can generally be taken at home, but can only target one allergen at a time.

Researchers examined data from surveys completed by 305 allergists. Overall, 91 percent reported using allergy shots and 74 percent reported using the newer tablets, the study team reports in the Annals of Allergy, Asthma & Immunology.

“The tablets work best if you have just one allergy that bothers you, like dust mite or grass,” said lead study author Dr. Anita Sivam of the University of Tennessee Health Science Center in Memphis.

“We still recommend allergy shots to the majority of patients because most patients have multiple allergies,” Sivam said by email.

Both shots and tablets are so-called immunotherapy treatments for allergies, meaning they work by targeting the immune system to improve tolerance of allergens and depleted cells, chemicals and antibodies that can cause allergy symptoms.

Over time, allergy shots and tablets allow patients to be exposed to pollen, dust and other allergens without having any reaction. Immunotherapy also reduces the inflammation that characterizes hay fever and asthma, so many sufferers find their symptoms improve.

Doctors typically give patients the first dose of an allergy tablet in the office, and after that prescribe tablets for people to take at home. With shots, patients return to the office for every dose.

In the study, 96 percent of allergists who used tablets required at least one dose to be administered in their office. About 3 percent made patients come in for two doses, 4 percent required office visits for three doses, and almost 2 percent required patients to come in for at least four doses.

Among allergists who used tablets, only 11 percent reported extensive experience with this approach and 38 percent said they had very little experience.

When allergists did use tablets, most of them reported using only tablets approved by the U.S. Food and Drug Administration. Some doctors, however, used other formulations “off label” to deliver similar active ingredients.

“This article confirms that there is continuously growing interest in using the lining of the oral cavity to deliver the same medications that allergy shots give,” said Dr. William Reisacher of Weill Cornell Medical College and NewYork-Presbyterian Hospital in New York City.

Allergy shots work by injecting the allergen proteins under the skin, while allergy tablets allow those proteins to adhere to the surface of the oral cavity lining, where they are slowly exposed to the immune system, Reisacher, who wasn’t involved in the study, explained by email.

“Both methods of delivering these proteins has been found to be effective,” Reisacher said.

SOURCE: bit.ly/2vNXjrw Annals of Allergy, Asthma & Immunology, online April 1, 2019.