MONDAY, March 6, 2006 (HealthDay News) -- People who are allergic to peanuts might be taking their life into their own hands if they kiss someone who has just eaten a peanut product, even if that person has brushed his or her teeth.
So claims research that was presented Monday at the American Academy of Allergy, Asthma and Immunology annual meeting, in Miami Beach.
Some 11 million Americans suffer from food allergies, and 150 to 200 people die each year from unknowingly ingesting the wrong food. Food allergies account for at least 30,000 emergency-room visits in the United States each year, and probably many more.
Allergy to peanuts is one of the most dramatic, and deadly, examples of a food allergy. The prevalence of this allergy has doubled in children in a five-year period.
Last year, a 15-year-old, peanut-allergic Quebec girl died after kissing her boyfriend, who had just eaten peanuts. It was thought that the kiss contained peanuts, and was therefore deadly. The Quebec coroner, however, recently announced that the girl had died from something else.
For the new study, researchers wanted to determine how much peanut allergen lingered in saliva after a meal, and after brushing teeth.
Ten people ate two tablespoons of peanut butter in a sandwich; their saliva was collected and tested after eating, and after cleaning their teeth.
By one hour after eating, the allergen level in six of the seven subjects was undetectable. But allergen remained in the saliva immediately after the meal, even after teeth cleaning or rinsing.
The study authors suggested that people might want to wait several hours after eating an allergen before kissing anyone.
Teenagers would do well to heed this and other advice, as another study found that food-allergic teens took risks according to different social circumstances.
Researchers asked 174 participants aged 13 to 21 to fill out questionnaires. Three-quarters of the individuals suffered from peanut allergy or two or more allergies; 82 percent had had anaphylaxis, a severe allergic reaction that can cause death; and 52 percent had had more than three such reactions during their lifetime.
"Teenagers are at high risk of dying from food anaphylaxis, and we wanted to see why," said study senior author Dr. Scott Sicherer, an associate professor of pediatrics at Mount Sinai School of Medicine in New York City. "Was it because they thought they were invincible, or because they were forgetful?"
Overall, 74 percent of respondents said they always carry epinephrine, the standard antidote for such allergic reactions, with them. But the percentage varied greatly according to activity, with 94 percent saying they carried epinephrine when traveling, but only 43 percent when playing sports.
"Children who were more likely to take risks were less concerned about the allergy," Sicherer stated. "There was an emotional difference."
Teens who wore tight clothing tended not to carry their epinephrine; and many did not realize that if they shared water at a sports event, they might end up with a reaction, Sicherer said.
In addition, three-quarters said they always read food labels, but 42 percent admitted they would eat a food with a label indicating that it "may contain" an allergen.
Only 60 percent of teens told friends about their food allergy, and 68 percent felt educating their friends would make life easier. However, most did not want to undertake that education themselves.
"They wanted other people to understand, but they didn't want to educate," Sicherer said.
Additional research presented at the meeting found that adults who had a severe allergic reaction to food and were prescribed epinephrine auto injectors (EAIs) had not received adequate follow-up from a health-care professional. Many were also not properly trained in using the device.
Finally, other researchers found that being exposed to peanut during infancy may sensitize a child to the food, and may protect some children from developing the allergy. There was no indication that mothers who ate peanuts while pregnant or breast-feeding increased the risk of their children developing the allergy.
Learn more about teens and food allergies at the Food Allergy and Anaphylaxis Network.