University Park, Pa. -- Immediate treatment of bee stings -- one
of the most common insect-caused injuries to humans -- should emphasize
quick removal of the sting, rather than the method by which the sting is
removed, according to entomologists at the University of California, Riverside
and Pennsylvania State University.
Writing in the Aug. 3 issue of The Lancet, an international medical journal published in Great Britain, the scientists challenge the conventional wisdom that a sting should be scraped off the skin rather than pinched out. The way it is removed has no bearing on the amount of bee venom that the sting injects, according to the scientists.
"We have always been told that pinching a bee sting out of the skin would cause more venom to be injected," said P. Kirk Visscher, associate professor of entomology at UCR. "What this study found is that the method of removal does not affect the quantity of venom received. Even small time delays do make a difference, though, so what is important is that the sting be removed as quickly as possible."
The finding goes against conventional advice that bee stings should be scraped out -- using a knife blade, credit card or fingernail -- and never plucked out by pinching with tweezers or fingernails. Visscher was skeptical of this advice because, although the sting remains in the skin and continues to inject venom, it does so through a valve system in the sting, not through compression as would occur with pinching.
To test the premise, Visscher and his UCR colleague, research entomologist Rick Vetter, made bees sting them on their own forearms, and measured the size of the resulting welts after scraping and pinching the stings out at various time intervals. Visscher and Scott Camazine, assistant professor at Pennsylvania State University, also showed that welt size is a good measurement of envenomization, by measuring the welts from injecting known quantities of bee venom into their skin with a syringe.
The longer the sting was allowed to remain in the skin, the larger the welt, indicating that more venom had been injected.
"What this illustrates is the significance of even short delays in removing the sting," said Visscher. "Any advice people are given about the importance of how the sting is removed is likely to cause delays, as they get out a knife, or even try to remember what to do.The method of removal is irrelevant, contrary to popular belief. The best advice for those stung by a bee is to simply remove the sting immediately."
For those who have dangerous allergic reactions to bee stings, removing the sting rapidly could be particularly important, Visscher said. Systemic allergic reactions are dose dependent, so the faster a sting is removed, the less venom is injected, and the less likely a person is to have dangerous whole-body responses like constriction of breathing or a drop in blood pressure.
Additionally, victims of bee stings should leave the area where they are stung since the attack may have been the response of a bee defending its nest, Visscher said. Once a bee stings, it emits a chemical alarm pheromone that signals other bees, making them more likely to sting.
"Getting to safety is more important than removing stings immediately, but stings should be removed as soon as possible once a person is away from the colony." A person who is stung 20 or more times or has a history of dangerous reactions to bee stings should seek medical attention, Visscher added.
The study was supported by funds from the National Science Foundation and the University of California.