What is anaphylaxis?

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What is anaphylaxis?

  • Anaphylaxis (pronounced anna-fill-ax-is) is a severe and potentially life-threatening allergic reaction affecting more than one body system such as the airways, heart, circulation, gut and skin. Symptoms can start within seconds or minutes of exposure to the food or substance you are allergic to and usually will progress rapidly. On rare occasions there may be a delay in the onset of a few hours.  
  • Anaphylactic reactions can be bi-phasic, which means that a second (or even third) reaction might occur after the first.  Anapen comes in a duo pack so that if the first dose is not sufficient to reverse the reaction, or the device does not work, that a second dose can be administered.  


What are the causes of anaphylaxis?

The common causes of anaphylaxis include foods such as peanuts, tree nuts, milk, eggs, shellfish, and fish, although many other foods have been known to trigger anaphylaxis.  Non-food causes include insect stings such as those from wasps or bees, natural latex (rubber), contraceptives, and certain drugs such as penicillin. In some people exercise can trigger a severe reaction – either on its own or in combination with other factors such as food or drugs (e.g. aspirin).  The causes of some reactions may not be known, and these are known as idiopathic reactions.

What are the symptoms of anaphylaxis?

Symptoms can appear suddenly and progress rapidly.  They can include:
  • Wheezing/difficulty breathing or swallowing
  • Swelling of the tongue/throat
  • Rapid heart rate
  • Feeling lightheaded/faint, clammy/sweaty
  • A raised/itchy rash on the skin
  • Flushing on the skin
  • Swelling of the eyes/lips
  • Vomiting/nausea
  • Tummy pains/diarrhoea
There may also be a dramatic fall in blood pressure (anaphylactic shock). The person may become very weak and may feel the sense of something terrible happening. This may lead to collapse, unconsciousness and – on rare occasions – death. See the articles on triggers, and tips on how to live with anaphylaxis, for more information.
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