Nov. 10 (Bloomberg) -- Allergy sufferers needed far fewer shots when doctors gave the injections into tiny glands called lymph nodes instead of the usual jab under the skin, a study found, suggesting an easier path to relief.

Three shots into the nodes in the groin offered the same protection against grass pollen as did 54 shots under the skin, researchers at University Hospital Zurich found. The ``intralymphatic'' shots were given over eight weeks, compared with three years for the traditional injections.

Patients often drop out of the standard treatment, known as immunotherapy, which can require 70 visits to the doctor over five years, and many participants receiving those shots in the study didn't finish. Patients getting the new treatment needed smaller doses, had fewer bad reactions and felt ``practically'' no pain.

``Evidently, intralymphatic immunotherapy is a more attractive treatment alternative,'' said Gabriela Senti, the lead researcher. The study, released today, is being published in the Nov. 18 issue of the Proceedings of the National Academy of Sciences, a U.S. journal.

The lymph nodes make up part of the immune system and fight intruders. Those include allergens, or substances that cause allergic reactions. Allergy shots work by introducing small amounts of allergens, in this case pollen extract, to increase the body's tolerance, much as vaccines work.

The problem with standard injections is that only a small fraction of the pollen aimed at the lymph nodes ever reaches them to stimulate an immune response, Senti said. With a direct shot, the injection delivers all of the vaccine into the gland, Senti said.

Less Pollen Injected

The new regimen reduced the cumulative amount of grass pollen injected into the patients more than 1,000-fold.

Senti studied 165 patients with grass pollen allergy who received either the standard therapy or a much reduced regimen with injections directly into the lymph nodes. She compared symptoms of patients in both groups after four months, one year and three years. After just four months, nasal symptoms declined.

Only 32 of 54 patients finished standard therapy, while all of the 58 patients receiving intralymphatic injections completed treatment. Almost half of the patients allocated to standard therapy didn't even show up for their first shot, most of them because they didn't fancy getting 54 injections, Senti said.

The Swiss National Science Foundation supported some scientists at the Swiss Institute for Asthma and Allergy Research, an institute that participated in the study.

To contact the reporter on this story: Chantal Britt at cbritt@bloomberg.net.

Last Updated: November 10, 2008 17:00 EST