WEDNESDAY, Aug. 11, 2004 (HealthDayNews) -- Contrary to popular belief, not all kids who are allergic to insect stings outgrow their sensitivity.
Some people whose allergies left them in fear of bees, wasps, and the like as children still react to their stings as adults, but a new study offers relief: Allergy shots given in childhood can protect them for up to 20 years.
The study appears in the Aug. 12 issue of the New England Journal of Medicine.
"There are inconveniences to allergy immunotherapy, but it's a good investment for some children because it protects them for a very long time," said Dr. Anna Nowak-Wegrzyn, an assistant professor of pediatrics at Mount Sinai School of Medicine in New York City, who was not involved with the study.
Most insect stings will cause pain and swelling at the site of the bite, which goes away in a few hours. One in every 30 to 300 people has a systemic reaction, ranging from skin problems at locations distant from the bite to difficulty breathing, dizziness, lowered blood pressure and, in some cases, even death. According to an editorial in the same issue of the journal, about 40 stings in the United States each year are fatal, although the actual number may be higher.
Allergy shots, also known as venom immunotherapy, are recommended for children who have moderate or severe systemic reactions to stings, such as difficulty breathing and lowered blood pressure.
And while the perception has been that adults are less prone to these reactions, there has been little evidence to back this up.
The authors of this study followed up with 500 of 1,033 individuals who had been diagnosed with allergic reactions to insect stings as children between 1978 and 1985. Of the initial 1,033, 356 subsequently received allergy shots.
Forty percent of the 500 reported additional stings in subsequent years.
Moderate and severe systemic reactions occurred in only 3 percent of adults who had received allergy shots as children, vs. 17 percent of adults who had not received earlier shots.
Moderate reactions included skin reactions, throat and chest discomfort, difficulty breathing, dizziness, and lowered blood pressure. Severe reactions consisted of skin reactions as well as more difficulty breathing, severe dizziness, marked low blood pressure, or unconsciousness.
Those with a history of moderate or severe reactions had a higher rate of reaction if they had not received allergy shots (32 percent) than if they had (5 percent).
Those who originally had moderate or severe reactions were most likely to have later allergic reactions to stings. They were also most likely to benefit from treatment.
The remaining 60 percent, who had only mild skin reactions, had a low risk of subsequent reactions and, for these reasons, are not in need of immunotherapy, the study authors concluded.
"Children who get stung and develop wheezing or a cough or low blood pressure or anything else in addition to a skin reaction are at high risk when they get stung," Nowak-Wegrzyn said, and they are the ones who should get shots.
Visit Cincinnati Children's Hospital for more on insect stings.