Based on an online survey, one in 12 kids in the United States may have a food allergy, according to new findings.
The study, published in Paediatrics, also showed that more than one third of those kids had severe allergies, and that allergies were more common in minority kids.
Allergies are a particularly difficult chronic condition because kids can't escape food in any part of their daily lives, said lead author Dr Ruchi Gupta, from the Northwestern University Feinberg School of Medicine in Chicago.
"What I hope this paper will do is open this awareness to how common (food allergy) is and how severe it can be, and develop policies for schools and sporting events and any activities that kids participate in to make it clear that everybody is looking out for these kids," she said.
Previous studies have estimated that anywhere between two and eight in every 100 kids in the US has a food allergy.
But most of those reports are based on studies that asked participants many different health questions, including only a few related to allergies, Gupta said. Other studies have also looked at emergency room trips for allergic reactions, or evaluated doctors' diagnoses in medical records.
Survey focused on allergies
Gupta and her colleagues instead wanted to design a study focused solely on the rate and severity of food allergies. They surveyed a nationally representative sample of almost 40,000 US adults who lived with a child under 18.
Those adults filled out an online questionnaire about allergies based on a single kid in their household, reporting whether or not the child had any signs and symptoms of a food allergy, had ever been diagnosed with an allergy by a doctor, and had ever had a severe allergic reaction to food.
The results, published in Paediatrics, showed that 8% of kids had a diagnosed food allergy or convincing symptoms that indicated an allergy - almost 6 million US kids, the researchers said. Kids were most commonly allergic to peanuts, milk, and shellfish.
What was interesting was not just how many kids had allergies, Gupta said, but how many of those allergies were severe –cutting off a kid's airway or causing blood pressure to drop.
"One of our big findings was that two in five kids who had allergies had a severe reaction or a life-threatening reaction," Gupta said.
"There are a lot of misconceptions of what allergies are," she added. "When you think of allergies, you don't think of life-threatening."
Severe reactions were more common in older kids, possibly because young kids with allergies are more likely to be monitored by parents to make sure they stay away from potential allergy triggers, Gupta explained.
She and her colleagues also found that black and Asian kids had higher chances of having a food allergy than white kids, but that they were less likely to have that allergy diagnosed by a doctor.
That disparity "needs to be addressed," said Dr Scott Sicherer, an allergy researcher at the Mount Sinai School of Medicine in New York.
Allergies risk may be increasing
"The family is saying that their child had convincing reactions and yet they weren't really evaluated to confirm that with a doctor," said Sicherer, who was not involved in the study.
"Is that because they're not getting the health care they need? Is that because there's not an appropriate amount of concern? I would be worried that the next reaction could be severe and they're not prepared for it."
While the findings can't show whether or not food allergies are on the rise, Gupta thinks that's the case.
"As a clinician, I see it a lot more," Gupta said. Sicherer agreed that he thinks food allergies are becoming more frequent, but said that researchers aren't sure why that is.
The next question, Gupta said, is whether there is something going on in the environment that is driving that increase.
(Reuters Health, Genevra Pittman, June 2011)
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