Nov. 16, 2009 -- The number of kids with reported food allergies has increased dramatically over the past two decades, but are kids really becoming more allergic over time?
Now new research from the CDC's National Center for Health Statistics offers compelling evidence that this spike in childhood food allergies is for real.
The study provides some of the "missing pieces" in our information on childhood allergies, says Amy Branum, lead author on the study and health statistician for the National Center for Health Statistics.
"Most of the studies ... up to this point have been in small populations and one demographic ... the fact that we are seeing increases in reported prevalence among children of different race and age groups gives more compelling evidence that these increases may be real," Branum says.
The study confirmed past findings that the prevalence for childhood allergies has increased at least 18 percent since 1993, and found that the number of visits to a physician, emergency room, or hospital clinic for food allergy-related care has tripled in that time period.
"[The] indication that more children are going to their doctors and emergency rooms for food allergies ... gives further evidence that we may be seeing a real rise in food allergy cases among children in the U.S.," Branum says.
Though the study cannot rule out increased reporting by parents as a contributing factor in this trend, allergists and pediatricians agree that food allergies in kids have become a growing concern.
Pediatric Food Allergies on the Rise
"These reports are solidifying what many pediatric allergists and pediatricians have been seeing since the later 1990's," says Dr. Harvey Leo, a pediatric allergist and researcher for University of Michigan's C.S. Mott Children's Hospital and School of Public Health.
"Definitely there has been an increase in the number of clinic visits for food allergy in the last 20 years," says Dr. Wesley Burks, chief of the Division of Pediatric Allergy and Immunology at Duke University Medical Center. "From my contacts in the American Academy of Allergy, Asthma and Immunology, most every practicing allergist has seen this same increase."
And it's not only an increase in the number of kids with a food allergy, Burks says. "We are also seeing a larger number of children with multiple severe allergies and more allergies to foods that years ago would not be common [such as] kiwi, sesame seed, [or] mustard."
Dr. Clifford Bassett, medical director of the Allergy and Asthma Care of New York, says "it's a mini-epidemic for sure."
A Squeaky Clean Society Spells Immune System Overdrive
What has brought on this mini-epidemic?
"That is the question that everyone wants to know the answer [to] and so far there is only speculation as to why," says Burks.
One theory is that certain foods, like nuts, may be introduced too early to children, perhaps as nut oils in creams or lotions used on infants, Bassett says.
"Changes in the environment and food processing" is also "thought to play a part," Burks says.
The leading theory explaining the effects of these environmental changes is called the hygiene hypothesis.
This theory "contends that immune systems become over-reactive in very clean environments, [like those] associated with the medicine and hygiene practices [used today]," says Dr. Bill Parker, assistant professor at Duke University Medical Center, and advocate of the hygiene hypothesis.
In these super-clean environments, he says, "the immune system essentially lacks a normal workload... however, [it] does what it is built to do, and finds something to attack, often directing its attention toward such harmless things as pollen grains ... even healthy food."
But whether it's exposure to certain foods too early or exposure to germs too late, once a child has an allergy, "the number one treatment is education [and] preventing reactions," Bassett says.
Treatment for the allergy itself may be possible "in the not too distant future" he notes, but for now, it is crucial for parents and children to ask questions, plan ahead, and be what he calls a "label detective", making sure that allergens are not hiding out in processed foods.
"Every year there are [more than a] hundred deaths attributable to food allergy, and a lot of near deaths," he says.
"People need to take it seriously."