Aug. 11, 2004 -- For most people, bee stings are merely painful reminders that summer has its downsides, but for those who are allergic, stings can be deadly. It has long been thought that kids usually outgrow allergic reactions to insect stings, but new research shows that this is often not the case.
In one of the largest and longest follow-up studies of children with insect sting allergies, Johns Hopkins researchers reported that dangerous allergic reactions to stings continued well into adulthood in a significant percentage of people. This was much less likely, however, when children were given allergy shots.
Just 5% of children with a history of severe allergic reactions to stings who received the allergy shots, known as venom immunotherapy, experienced moderate to severe allergic reactions to stings as adults. In contrast, 32% of the study participants experienced serious allergic reactions to stings later in life if they had not been given the allergy shots.
"The good news is that 62% of the children did appear to outgrow allergies to insect stings, but the bad news is that the rest did not," lead researcher David Golden, MD, tells WebMD. "The ultimate goal of our research is to come up with tests to tell the two groups apart."
The Buzz on Bee Stings
There are roughly 40 fatal allergic reactions to bee, wasp, and other insect stings in the U.S. each year. Studies suggest that 1% of children and 3% of adults have life-threatening allergic reactions to stings that go beyond the expected swelling and pain. These reactions could range from slight difficulty breathing and dizziness to shock.
Approved by the FDA in 1979, venom immunotherapy involves injections of purified bee or other insect venom given in small doses to build up tolerance to the sting over time. Treatments typically last three to five years.
While the therapy is generally recommended for children with a history of moderate to severe reactions to insect stings, it is widely underused even though it is highly effective, Golden says.
In an effort to determine the persistence of insect sting allergies and the protection conveyed by the treatment, Golden and colleagues collected follow-up data on more than 500 children six to 32 years after they were treated for allergic reactions to insect stings. The findings are published in the Aug. 12 issue of TheNew England Journal of Medicine.
Some 40% of the participants had been stung again after their initial sting. Moderate reactions to stings included throat and chest discomfort, difficulty breathing, dizziness, and low blood pressure. A reaction was considered severe in cases involving serious breathing difficulties, severe dizziness, marked low blood pressure, or unconsciousness.
Roughly a third of the untreated adults who had experienced moderate to severe reactions as children had similar reactions to later stings, compared with one in 20 treated adults.
See a Specialist
Golden says the findings make it clear that venom immunotherapy is a good idea for children with a history of moderate to severe allergic reactions.
"The message to pediatricians is that their patients who have had these reactions need to be referred to a specialist for evaluation and treatment," Golden says. "And the message for doctors treating adults is that it is important to know a patient's history. They need to understand that a 30-year-old who tells you he had a bad reaction to a bee sting as a kid may still be at risk."
In an editorial accompanying the study, Rebecca Gunchalla, MD, PhD, writes that the new findings disprove the notion that immunotherapy is not needed in children because they outgrow sting allergies.
"It is to be hoped that now, with hard data provided, physicians will be able to move beyond misconceptions and support the use of venom immunotherapy for the children most at risk," she writes.
In an interview with WebMD, Gunchalla says evaluation by a specialist is important for any child who exhibits abnormal reactions to stings. Gunchalla is chief of the allergy division of internal medicine and associate professor of pediatrics at the University of Texas Southwestern Medical Center in Dallas.
"If a child shows signs of anaphylactic shock, it is an easy call, but there may be nothing more than some coughing and some chest tightening," she says. "Even so, it is important to see a specialist for anything more serious than normal skin reactions."