William E. Berger, M.D., M.B.A. Clinical Professor Department of Pediatrics Division of Allergy and Immunology University of California, Irvine

Transcription

1 Allergic Reactions & Access to Emergency Response William E. Berger, M.D., M.B.A. Clinical Professor Department of Pediatrics Division of Allergy and Immunology University of California, Irvine

2 Mechanistic Definition Anaphylaxis: A severe, acute, systemic allergic reaction caused by the rapid, IgEmediated release of potent mediators, such as histamine, from tissue mast cells and peripheral basophils Reference: Sicherer S. How to recognize and manage anaphylaxis: the key points. J Respir Dis Pediatrician. 2003;5(5):

3 Incidence and Severity Underestimated Fatalities due to anaphylaxis are underreported Estimates are 500 to 1000 deaths in the US each year Likely that some deaths attributed to other causes Prevalence underestimated due to improper use of ICD-9 codes Neugut AI, Ghatak AT, Miller RL. Anaphylaxis in the United States: an investigation into its epidemiology. Arch Intern Med. 2001;161:15-21.

4 Incidence in U.S. Analysis of published studies of most common causes 3.3 to 4 million Americans at risk 1,433 to I,503 at risk for fatal reaction Neugut, et al. Arch Int Med. 2001;161,15-21.

5 Incidence of Severe Episodes Severe episodes affect one to three per 10,000 people world wide, but the incidence is even higher in the U.S. Death occurs in 0.65 to 2.0% of those with severe events (1 to 3million people) Moneret-Vautrin M. Allergy :443.

6 Incidence/Prevalence Incidence of anaphylaxis associated with the following primary allergen sources Food As many as 11 million or 4% of the population have a food allergy Approximately 6.6 million people reported seafood allergy 58% reported recurrent reactions Insect venom 13 million or 5% of Americans suffer from severe allergic reactions to insect stings or bites Latex Affects 16 million or up to 6% of US population Medications Estimated 550,000 serious allergic reactions to medications per year in US hospitals References: Neugut AI, Ghatak AT, Miller RL. Anaphylaxis in the United States: an investigation into its epidemiology. Arch Intern Med. 161: 2001;161: Sampson HA. Update on food allergy. J Allergy Clin Immunol. 2004;113: Sicherer SH, Muñoz-Furlong A, Sampson HA. Prevalence of seafood allergy in the United States determined by a raandom telephone survey. J Allergy Clin Immunol. 2004;114: Lazarou J, Pomeranz BH, Corey PN. Incidence of adverse drug reactions in hospital patients.jama.1998;279:

7 Food-Induced Anaphylaxis: Incidence 35% to 55% of anaphylactic reactions are caused by food allergies Accidental food exposures are common and unpredictable Prevalence of food hypersensitivities is greatest in the first few years of life 6% of infants <3 years of age affected Decreases over first decade Prevalence is increasing Prevalence of peanut allergy has doubled in children <5 years of age in the last 5 years Sampson HA. Update on food allergy. J Allergy Clin Immunol. 2004;113:

8 Food-Induced Anaphylaxis: Prevalence 2004 Seafood Study Approximately 6.6 million Americans (2.3% of the population) reported seafood allergy Most with recurrent and sometimes severe reactions Finned fish or shellfish allergy reported in 5.9% of households Among individuals 2.3% for any seafood allergy 2% for shellfish 0.4% for fish 0.2% for both types Allergy onset in adulthood for 39.7% with fish and 60.1% with shellfish allergy 7 Sicherer SH, Muñoz-Furlong A, Sampson HA. Prevalence of seafood allergy in the United States determined by a random telephone survey. J Allergy Clin Immunol. 2004;114:

9 Food-Induced Anaphylaxis: Common Triggers Children and adults Peanuts Tree nuts Shellfish Fish Additional triggers in children (commonly outgrown) Milk Eggs Soy Wheat The above 8 foods account for 90% of all allergic reactions to food 3 The Food Allergy and Anaphylaxis Network (FAAN). Available at: Accessed January 28, 2005.

10 Venom-Induced Anaphylaxis: Incidence 0.5% to 5% or 1.36 million to 13 million Americans are sensitive to one or more insect venoms Hymenoptera order of insects Bees Wasps Yellow jackets Hornets Fire ants At least 40 to 100 deaths per year Incidence increasing due to Rise in the number of fire ants and Africanized bees Increase in people engaging in outdoor activities 8 Neugut AI, Ghatak AT, Miller RL. Anaphylaxis in the United States: an investigation into its epidemiology. Arch Intern Med. 2001;161:15-21.

11 Medication-Induced Anaphylaxis: Incidence Estimated 550,000 serious allergic reactions to drugs/year in US hospitals Reactions to penicillin: highest number of documented deaths from anaphylaxis each year Most common triggers Antibiotics especially beta-lactams Non-steroidal anti-inflammatory agents Neugut AI, Ghatak AT, Miller RL. Anaphylaxis in the United States: an investigation into its epidemiology. Arch Intern Med. 2001;161:15-21., Lazarou J, Pomeranz BH, Corey PN. Incidence of adverse drug reactions in hospitalized patients. JAMA. 1998;279:

12 Other Causes of Anaphylactic and Anaphylactoid Reactions Diagnostic agents (Radiocontrast media) Exercise Biological agents (vaccines, monoclonals) Idiopathic Kemp SF, Lockey MD. Anaphylaxis: a review of causes and mechanisms. J Allergy Clin Immunol. 2002;110:

13 Idiopathic Anaphylaxis In one study, at least 50% of anaphylactic episodes were idiopathic In another study, more than 70% of cases were found to be idiopathic Triggers unknown in spite of skin testing, extensive dietary history, and assessment of all possible causes, such as mastocytosis Conclusion: Many cases of anaphylaxis are of unknown origin, making prevention difficult Medem-ACAAI Medical Library Web site. Available at: ACAAI. Accessed November 1, 2004., Brunell PA, Bellanti JA, Gawchik SM, et al. Understanding anaphylaxis: defining, identifying and treating severe reactions. Infect Dis Child. (CME training materials.) April 2004.

14 Sicherer S. How to recognize and manage anaphylaxis: the key points. J Respir Dis Pediatrician. 2003;5(5): Simons FE. First-aid treatment of anaphylaxis to food: focus on epinephrine. J Allergy Clin Immunol. 2004;113: Epinephrine: The Treatment of Choice for Anaphylaxis Epinephrine is the treatment of choice for anaphylaxis The benefits of epinephrine administration during anaphylaxis far outweigh the risks There is no absolute contraindiction to epinephrine use in anaphylaxis Caution is warranted when administering epinephrine to elderly patients or those with known cardiac disease

15 Intramuscular injection in the lateral thigh gives the most rapid rise in blood level

16 IM vs SQ Epinephrine Intramuscular epinephrine (Epipen ) Subcutaneous epinephrine 34 ± 14(5-120) minutes p<0.05 Simons. J Allergy Clin Immunol. 2004; 113: Time to C max after injection (minutes)

17 More than one dose is needed a significant number of times

18 In Spite of the Fact that It Is the Drug of Choice, It Is Under-utilized 0nly 49% of 79 children Rx d in ER in Australia received EPI Only 32% of Canadian children with episodes were given EPI When patients know the antigen they are less likely to keep kit with them Allergy Clin Immun Int, 2003:18s JACI 2002:109,s181

19 Major Causes of Death 214 deaths reported by Pumphrey in which the cause was determined in shock 96 asphyxia (49 lower airway, 22 upper, 25 both or unspecified) 7 DIC 5 Epinephrine overdose Severity previous reaction not predictive Pumphrey RSH. Clin Exp Allergy. 2000;30,1144.