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.