Most children who suffer an allergic reaction to insect stings usually outgrow them, but nearly 1 in 6 remain sensitive as adults, contrary to conventional wisdom, according to new research.
The study also found that insect venom injections that prevent such allergic reactions remain surprisingly effective many years after the treatments end.
And among children who suffer only a mild reaction after their first bee sting, the chance of having a more severe reaction when they are stung as adults is very low.
Insect stings kill at least 40 people per year in the United States.
"Although the majority of children with allergy to insect stings do not have allergic reactions when they are older, a clinically important number of children do not outgrow this allergy," said the team led by David Golden of Johns Hopkins Asthma and Allergy Center in Baltimore.
The researchers wrote in the New England Journal of Medicine that venom treatment "should be recommended for children with moderate-to-severe reactions, but there is little need for such therapy in patients with milder reactions."
That advice is based on an assessment of 512 people who were stung as children from 1978 to 1985. The team contacted them between 1997 and 2000 to see if subsequent stings had caused additional problems.
They found that just 17 percent of the 111 children who had a systemic reaction, where symptoms might include chest discomfort, difficulty breathing or dizziness, had a similar reaction to a sting after they grew up.
Those who were treated with venom injections were significantly less likely to have problems if they were stung again, even if they hadn't had a shot in years.
Among 64 children who had received venom therapy to desensitize them to the effects of the sting, the rate was just 3 percent.
"For children with moderate to severe reactions, allergy shots will lower the risk of serious reactions to stings even 10 to 20 years after treatment is stopped," said Golden.