Less frequent shots for bee allergy not safe

NEW YORK (Reuters Health) - For people getting allergy shots for bee-sting allergies, six months is likely too long to wait between treatments, a study suggests.

People with severe allergies to stings from bees, wasps and other insects can opt for a treatment known as immunotherapy. The therapy involves exposure to tiny amounts of venom that activates a small allergic reaction.

The idea is to stimulate the immune system to build up a tolerance to the venom; over time, the treatment can prevent allergic reactions in most people. However, immunotherapy is a process that takes several years or, in some cases, needs to continue indefinitely.

At first, patients typically get a dose of venom extract once a week, and gradually move on to "maintenance" doses that are given at intervals of one to three months.

In the new study, researchers at Tel-Aviv University in Israel looked at whether the intervals could be safely expanded to six months.

Drs. Arnon Goldberg and Ronit Confino-Cohen recruited 47 adults with bee-sting allergies, and gradually increased their maintenance immunotherapy from three-month to six-month intervals.

Fourteen of the patients were then deliberately exposed to a bee sting in the laboratory to see whether they would have an allergic reaction. Three of them did, the researchers report in the Annals of Allergy, Asthma and Immunology.

In addition, of two patients who were stung by a bee under natural conditions, one had a mild allergic reaction.

According to the researchers, one previous study suggested that people who are allergic to wasp venom might be able to go six months between immunotherapy treatments. However, they point out, those results do not necessarily apply to bee-sting allergies, which tend to respond less well to immunotherapy than wasp-sting allergies do.

Based on the current findings, they conclude that most people with bee-sting allergies cannot safely go six months between immunotherapy doses.

SOURCE: Annals of Allergy, Asthma and Immunology, October 2007.