NEW YORK - A yellow jacket sting can be more
dangerous if a certain species of the insect is doing the stinging, a new study
shows.
Of the two most common yellow jacket species found in the eastern US, Vespula
maculifrons -- which tends to live in large underground nests -- is much more
likely to cause a systemic reaction than is Vespula germanica, Dr. David B. K.
Golden of the Johns Hopkins Asthma and Allergy Center in Baltimore and
colleagues found.
This means that if a person with a history of severe reactions to yellow
jacket stings gets stung again without reacting severely, the milder sting may
simply have come from the milder species -- and doesn't mean the person has
outgrown the allergy, Golden explained in an interview with Reuters Health.
"What we hear from people is that 'oh it was a fluke, it will never happen
again'," he said. "That's certainly not something you can count on."
A systemic reaction extends beyond the area where a person was stung, and can
range from mild responses such as light-headedness to potentially fatal
reactions such as swelling that closes off the windpipe or a dramatic drop in
blood pressure.
Golden and his team initiated their study to determine why some people react
severely to yellow jacket stings and others don't. They tested reactions to
yellow jacket venom in 111 healthy volunteers, who received a total of 175 sting
challenges over a three-year period, and report the results in the Journal of
Allergy and Clinical Immunology.
V. maculifrons was more likely to produce a systemic reaction than V.
germanica, the researchers found. And these reactions were more common among
people who had experienced such a reaction previously. Among people with a
history of systemic reactions to yellow jacket stings, 41 percent had a systemic
reaction to V. maculifrons. But among those who had not experienced systemic
reactions in the past, just 3 percent exhibited systemic reactions to V.
germanica.
The findings show that even if a person has escaped a severe reaction with a
yellow jacket sting in the past, he or she is not safe from having one in the
future, the researchers conclude.
Anybody who has suffered a severe reaction to a wasp, bee or yellow jacket
sting should be evaluated by an allergist, Golden told Reuters Health, because
immunization is available for allergies to each type of venom that is 98 percent
protective against future severe reactions.
SOURCE: Journal of Allergy and Clinical Immunology
