Almost 4% of American children have food allergies, according to a sweeping analysis of the problem published today in the journal Pediatrics.
The study is the first to make a broad estimate of the prevalence of food allergies among U.S. children and supports previous, smaller studies suggesting that food allergy rates are rising rapidly for reasons that are unclear.
Researchers from the Centers for Disease Control and Prevention found that self-reported food allergies increased 18% from 1997 to 2007.
The estimates were drawn from surveys of the children's parents and from medical records. Using data from medical records taken in 2005-06, researchers found 9% of all children tested positive for immunoglobulin E antibodies to peanuts. IgE tests are not considered reliable indicators of an allergy, but they do suggest an increased risk or past history of an allergy. The antibody tests were positive for egg allergies in 7% of children, for milk allergies in 12% and for shrimp allergies in 5%.
Finally, the analysis showed that healthcare visits for food allergies in children nearly tripled between the two time periods studied: 1992 through 1997 and 2003 through 2006. In the later period, U.S. children had an average of 317,000 visits to healthcare settings per year for food allergies.
The study also suggests potential racial differences among children with food allergies. While Latino children had the lowest prevalence of food allergies in 2007 compared with other racial groups, they had the greatest increase in reported food allergies over the time period studied.
"We used four different surveys, and to see an increase in food allergies in all of those surveys is very telling," said the lead author of the study, Amy M. Branum of the National Center for Health Statistics. "This is not just limited to one demographic or age group."
-- Shari Roan
Photo credit: Al Schaben / Los Angeles Times