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World Allergy Organization
WAO's mission: To be a global resource and advocate in the field of allergy, advancing excellence in clinical care through education, research and training as a world-wide alliance of allergy and clinical immunology societies.

Disease Summaries

Anaphylaxis: Global Overview

A panel of World Allergy Organization experts was asked to complete an informal survey on prevalence and treatment of anaphylaxis in their countries. Responses were received from Australia, China, France, Hungary, Japan, Korea, South Africa and the USA. The responses from South Africa were limited through lack of data, because there are only 9 specialists in allergy serving a population of 43 million people.

Estimates for the number of episodes of anaphylaxis seen in emergency rooms ranged from 222 known episodes per annum in Hungary, for a population of 10.2 million; through 300-350 episodes per annum in Japan, for a population of 100 million; to 3,000 episodes per annum in China, in a population of 1,200 million. Estimated prevalence rates ranged from 2% of the population in the United States of America, to 0.1% of the population in Korea, and 0.6-1% of the population in Australia.

Where it was possible to provide estimates for the number of deaths occurring each year due to anaphylaxis, this ranged from 5 or less in Hungary, 44 in Japan, to 500 in both China and the United States of America.

Anaphylaxis, and deaths from anaphylaxis, are reported to be more frequent in adults than in children. An exception is Australia, where the incidence of anaphylaxis is thought to be equal between both groups. Deaths from anaphylaxis occur primarily in adults, second, in children in the under-5 age group, and then in adolescents. Causative allergens reported are the same worldwide, but the relative salience varies between countries. In Japan, Hungary, China and Korea, drugs, such as antibiotics and anesthetic agents, are thought to be the most important allergens implicated in anaphylaxis. In India, antibiotics, radiocontrast agents and anesthetic agents are considered major causes of anaphylaxis, and blood products, insulin and growth hormones are also mentioned. Respondents from the USA considered that insect venom and drugs were the most important causative allergens, followed by reactions to immunotherapy, foods and radiocontrast media. In France, the most important allergens are listed in order as food, latex, insect venom and muscle relaxants. In Australia, peanuts are considered to be the most prominent cause of anaphylaxis. Peanuts are thought to be the second most important cause of anaphylaxis in China. In Japan, anaphylaxis due to foods is more common in children, whereas that due to bee and insect stings, latex and drugs is more common in adults.

All countries, apart from the USA, reported that emergency episodes of anaphylaxis are appropriately treated in emergency rooms, and that emergency room receptionists are generally aware of the necessity to treat anaphylaxis as a true medical emergency.

Referral to an allergist for follow-up of an anaphylaxis episode is made in all cases in Hungary and Korea, but not routinely in other countries, in some cases because there are insufficient allergy specialists to accept referrals. Apart from Hungary, where most patients receive emergency kits of adrenaline/epinephrine auto-injectors for emergency use, most respondents reported that very few, if any, patients were prescribed these.

Long term therapy for different allergens differs between countries. Regimens recommended include:

Foods:

  • Avoidance (all respondents)
  • Addition of adrenaline/epinephrine auto-injector and/or H1 and H2 antihistamines (USA)
  • Addition of pre-medication with disodium cromoglycate (India, Japan)

Insect Stings:

  • Immunotherapy (5 respondents)
  • Immunotherapy or adrenaline/epinephrine auto-injector (USA, Australia)
  • Avoidance or immunotherapy (Korea)
  • Avoidance (China)

Latex:

  • Avoidance (all respondents)
  • Additional trial of immunotherapy (France)
  • Avoidance, and recommendation of alternative products (Hungary)
  • Avoidance, and first-aid use of adrenaline (Australia)

Drugs:

  • Avoidance (all respondents)
  • Consider desensitization (Australia)
  • Trial of similar drugs with different structure (Hungary)

Anesthetic Agents:

  • Avoidance (all respondents)

Summary

Anaphylaxis is a worldwide problem, and a true medical emergency. Anaphylaxis results in a significant number of deaths each year. The major causative allergens are common to all populations. Prophylactic therapy in the form of epinephrine/adrenaline auto-injectors is only prescribed to a small proportion of the patients around the world at risk of suffering a repeat episode of anaphylaxis.