Flouting widely held beliefs that yellow jacket stings have less effect early in the season and that most people can outgrow a dangerous allergic reaction to a sting, allergists at Johns Hopkins School of Medicine have concluded that the sting severity is determined not by the calendar but by the species of insect doing the stinging.
"As far as stings go, some yellow jackets are worse than others," says David Golden, M.D., an associate professor of allergy and immunology at The Johns Hopkins University School of Medicine. "Because we've found that the severity of an allergic reaction is related to the species of yellow jacket, it's important for people to understand that they can have wildly different reactions depending on which species stings them and that getting stung once without an allergic reaction does not guarantee that a more serious reaction will not happen with a later sting."
Published in the Journal of Allergy and Clinical Immunology, the study by Golden and his research team involved 111 patients who had all tested allergic to yellow jackets. The researchers performed 175 test stings with two different species of yellow jackets and closely monitored the study participants for physical symptoms resulting from the stings, such as flushing, changes in vital signs, dizziness, shortness of breath and hives.
Over time Golden, whose original research goal was to find out why some people have allergic reactions to stings while others do not, began to notice that subjects were having fewer reactions to a particular species of yellow jacket, leading them to restructure and analyze the data they had collected at the three-year mark. They found that allergic reactions were much more common, and nastier, with the yellow jacket called Vespula maculifrons than with the one named Vespula germanica. These are the two most common species in the eastern United States, but most people can't tell them apart.