MONDAY, Nov. 16 (HealthDay News) -- Pediatric food allergies, which can sometimes be life-threatening, are increasing at a dramatic rate in the United States, new research shows.
But the study authors aren't sure if the rise in reports of food allergies reflects an increase in actual prevalence or if better awareness has led more people to seek treatment for their symptoms.
Whatever the cause, it's clear that the number of children with food allergies has gone up 18 percent and the number seeking treatment for food allergy at emergency departments or hospitals has tripled since 1993.
"People are more aware of food allergies today, and that could have something to do with it," said study author, Amy Branum, a health statistician for the U.S. Centers for Disease Control and Prevention. "But, when we looked at health-care surveys filled out by parents and those from the health-care sector, we saw the increase across the surveys so this may be more than just increased awareness."
Results of the study were published online Nov. 16 and will appear in the December print issue of Pediatrics.
Although many people think of allergies as more of a nuisance than a serious health issue, food allergy in particular can be very serious, even life-threatening. The most common foods that people are allergic to include peanuts, tree nuts, milk, eggs, soy, shellfish, fish and wheat, according to the Food Allergy & Anaphylaxis Network.
Symptoms often appear minutes after people eat a food that they're allergic to, but it can sometimes take several hours before a reaction begins, according to the network. Typical symptoms of a food allergy include a tingling sensation in the mouth, swelling of the tongue or throat, trouble breathing, hives, stomach cramping, vomiting or diarrhea.
In the current study, the researchers used information from four different national data sources to assess the current rate of food allergies in the United States. The surveys included information from parents and from health-care providers, according to Branum.
The researchers found that between 1997 and 2007, the incidence of food allergy went up by 18 percent. Parents of almost 4 percent of U.S. children reported a food or digestive allergy in their child, the study authors noted.
There was also an increase in the rates of parent-reported skin allergy (eczema) during the same time period. Approximately 8.9 percent of U.S. children had experienced skin allergy in 2007, compared with 7.9 percent in 1997.
Health-care providers, on the other hand, reported that the number of children being treated for food allergies had tripled, the study found. Data from health-care providers was from 1993 to 2006.
Data included testing for immunoglobulin E, or IgE, antibodies in the blood for various foodstuffs, which can indicate an allergy. The percentage of children who tested positive for IgE antibodies for peanut allergy was 9 percent; for egg allergy, 7 percent; milk, 12 percent; and shrimp, 5 percent, the study found.
Though IgE antibodies can indicate a potential food allergy, the test is often better at ruling out who does not have an allergy, Branum said. A positive test doesn't mean that someone definitely has a food allergy, but suggests that the potential is there.
The researchers also noted that Hispanic children had the lowest overall prevalence of food allergy but the greatest increases over time of parent-reported incidences of food allergy.
"People should be aware that food allergy may really be increasing," Branum said. "If small children have symptoms when they eat a particular food, have that child checked out, particularly if they have co-occurring conditions like asthma and eczema."
"Food allergies are real," said Dr. Jennifer Appleyard, chief of allergy and immunology at St. John Hospital and Medical Center in Detroit. "And it appears that the prevalence is rising."
This will present various challenges, she noted. One is that there's already a shortage of allergy specialists in many areas, Appleyard said. Another is that schools will have to gear up to take care of additional children with food allergy to ensure their safety during the school day and on field trips, she said.
Parents who suspect their child has a food allergy should first talk with the child's primary care physician about symptoms. The problem could be a food intolerance rather than an allergy, she said, but the child might need to be tested by an allergy specialist to get a definitive diagnosis.
The Food Allergy & Anaphylaxis Network has more on food allergies.
SOURCES: Amy Branum, M.S.P.H., health statistician, U.S. National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Md.; Jennifer Appleyard, M.D., chief, allergy and immunology, St. John Hospital and Medical Center, Detroit; Nov. 16, 2009, Pediatrics, online