An estimated 3 million to 43 million people in the United States are at risk of anaphylaxis, representing 1.2% to 16% of the population.1 Up to 8% of all children are estimated to have mild to severe food allergies, and half of all severe pediatric anaphylaxis is food related. In addition to food allergies, 3% of US adults and children have allergies to insect stings, 1% to 6% are sensitive to latex, and 2% are allergic to penicillin.2-4
Annually, tens of thousands of people in the United States experience anaphylactic reactions, including 1 in every 3000 hospitalized inpatients.1 Anaphylaxis can occur at any age, but US studies suggest that reactions due to food allergies are more common in children than in adults. Peanut and tree-nut allergies have emerged as the most prevalent and fastest-growing cause of food-related anaphylactic reactions in the country. Between 1997 and 2002, the documented rate of nut allergy in children doubled.5
A summary of published studies states that among documented reports of anaphylaxis treatments in the United States, reactions were caused by food in 35% of cases, drugs and biological sources in 20%, insect stings in 20%, exercise in 5%, and allergen desensitization therapy in 3%; 20% of reported cases were idiopathic in nature.6 In recent years, the incidence of anaphylaxis in the United States has increased, especially among children.1
The acute management of anaphylaxis involves a rapid, initial assessment to determine that the symptoms are actually anaphylactic and not symptoms of respiratory or cardiovascular acute illnesses. Once the diagnosis has been confirmed, epinephrine should be administered immediately by intramuscular injection, and the patient should be transported to an emergency care facility.
Flexibility in dosing is needed in order to treat effectively. Data suggest that up to 35% of patients require more than a single epinephrine injection, and different-sized doses are needed for children and adults.7 After the initial dose of epinephrine, subsequent doses may be repeated every 10* minutes or as necessary to resolve the anaphylactic reaction. All patients, regardless of previous anaphylactic histories, may be at risk of a biphasic, protracted, or delayed reaction.8 Ideally, every patient should be observed for at least 4 hours before discharge from the hospital.
Guidelines included in the current Joint Task Force on Practice Parameters advise that all patients who are discharged from the hospital following treatment for anaphylaxis should receive a prescription for a self-administered epinephrine auto-injector, if they do not already have one.8
*Some recent publications recommend repeated doses as early as 5 minutes.8
REFERENCES 1. Neugut AI, Ghatak AT, Miller RL. Anaphylaxis in the United States: an investigation into its epidemiology. Arch Intern Med. 2001;161:15-21. Review. 2. Arellano R, Bradley J, Sussman G. Prevalence of latex sensitization among hospital physicians occupationally exposed to latex gloves. Anesthesiology. 1992;77:905-908. 3. Ownby DR, Ownby HE, McCullough J, Shafer AW. The prevalence of anti-latex IgE antibodies in 1000 volunteer blood donors. J Allergy Clin Immunol. 1996;97:1188-1192. 4. Ring J, Brockow K, Behrendt H. History and classification of anaphylaxis. Novartis Found Symp. 2004;257:6-16; discussion 16-24, 45-50, 276-85. 5. Sicherer SH, Munoz-Furlong A, Sampson HA. Prevalence of peanut and tree nut allergy in the United States determined by means of a random digit dial telephone survey: a 5-year follow-up study. J Allergy Clin Immunol. 2003; 112:1203-1207. 6. Golden DB. Patterns of anaphylaxis: acute and late phase features of allergic reactions. Novartis Found Symp. 2004;257:101-110; discussion 110-115, 157-160, 276-85. Review. 7. Korenblat P, Lundie MJ, Dankner RE, Day JH. A retrospective study of epinephrine administration for anaphylaxis: how many doses are needed? Allergy Asthma Proc. 1999;20:383-386. 8. Joint Task Force on Practice Parameters; AAAI; ACAAI; JCAAI. The diagnosis and management of anaphylaxis: an updated practice parameter. J Allergy Clin Immunol. 2005;115(Suppl):S483-S523.
