Study Shows 1 Dose of Epinephrine Isn't Always Enough to Treat Severe Allergic Reactions
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Reviewed By Laura J. Martin, MD
March 26, 2010 -- Children with a history of severe food allergies should carry two doses of self-injectable epinephrine instead of one, a new study suggests.
Researchers reviewed outcomes among more than 1,200 children treated for food allergies in emergency rooms at two large Boston hospitals between 2001 and 2006.
During their allergic reactions, 44% were treated with epinephrine and about one in 10 of these children needed more than one dose.
It is recommended that children and adults with a history of severe food allergy reactions carry injectable epinephrine at all times.
The most widely prescribed self-administered epinephrine is the EpiPen auto injector.
Pediatric allergist and study researcher Susan Rudders, MD, of Children's Hospital Boston, says the study confirms two pens offer more protection than one.
The research appears in the April issue of Pediatrics.
"Eighty-eight percent of kids were fine with just one pen, but 12% needed two doses," she tells WebMD. "The problem is, we really don't have good ways of identifying who will and will not need an extra dose."
Each year in the U.S., between 150 and 200 people die from anaphylaxis, a serious allergic reaction marked by hives, swelling, and lowered blood pressure, after knowingly or unknowingly eating foods they are allergic to, Rudders says.
Immediate treatment with injected epinephrine can keep these allergic reactions from becoming life threatening.
But even in the hospital emergency department setting, anaphylaxis is often misdiagnosed, she says.
Having symptoms in two or more systems of the body, such as hives and throat swelling or trouble breathing and skin rashes, within 10 to 15 minutes of eating should raise suspicions of food-induced anaphylaxis.
The Boston study indicated that epinephrine is underused and practice guidelines are not always followed.
Those guidelines recommend epinephrine as the first-line treatment for food-related anaphylaxis in children. In addition, patients should be referred to an allergist, taught about how to avoid problem foods, and be sent home with self-administered epinephrine.
Although 52% of the kids in the study received a diagnosis of food-related anaphylaxis, just 31% received one dose of epinephrine, and 3% received more than one dose before arriving at the hospital. Once there, 59% were treated with antihistamines, 57% were treated with steroids, and just 20% were treated with epinephrine.
At discharge, less than half (43%) of patients were prescribed self-injectable epinephrine, and roughly one in five was referred to an allergist.
Peanuts, tree nuts, and milk triggered the most allergic reactions, but fruits and vegetables, shellfish, and eggs were also implicated. In about one in five cases, some another food caused the reaction.
Food Allergies on the Rise
According to the CDC, the number of Americans with food allergies has increased by about 20% in just over a decade.
Mount Sinai School of Medicine professor of pediatrics Scott H. Sicherer, MD, says his own research and the research of others has shown that two doses of epinephrine are often needed.
"It has been the general practice here to advise most patients to carry two doses of epinephrine," he says.
Sicherer tells WebMD that parents of children with food allergies need to have an action plan in case anaphylaxis occurs.
"The most important thing is having epinephrine within reach and knowing how and when to use it," he says. "Our own research shows that many times families, and even physicians, don't know how to properly use it."
SOURCES: Rudders, S. Pediatrics, April 2010; vol 125: pp: e711-e718.
Susan A. Rudders, MD, division of allergy and immunology, Children's Hospital Boston.
Scott H. Sicherer, MD, professor of pediatrics, Jaffe Food Allergy Institute, Mount Sinai School of Medicine, New York City.
News release, Children's Hospital Boston.
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