Anaphylaxis or Anaphylactic Shock is a severe allergic reaction. It is caused when the immune system has an overreaction to an allergen.

An allergen is a trigger and might include foods, such as dairy products, nuts or seafood, medication, latex or insect stings.

Almost anything can be an allergen. A reaction usually happens on the second or subsequent exposures to an allergen.

The reaction will often happen very quickly, within a few minutes of exposure to the allergen, but sometimes may take several hours.

In severe cases, there is a sudden drop in blood pressure and narrowing of the airways, which will lead to difficult and wheezy breathing. This makes the reaction potentially life threatening.

Possible Signs and Symptoms:

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  • Itchy flushed skin
  • Nettle like rash or hives
  • Swelling of the mouth & throat
  • Difficulty in swallowing or speaking
  • Severe asthma
  • Abdominal pain, feeling or being sick
  • Feeling faint & weak (drop in blood pressure)
  • Collapse and unconsciousness


  • Remove the trigger if possible
  • Dial 999 for an ambulance
  • Reassure the casualty
  • If the casualty is not having breathing difficulties, lie them down and raise their legs
  • If the casualty is having difficulty breathing, keep them sat upright
  • If the casualty stops responding, use your emergency plan

MedicationAction for Anaphylaxis

  • The casualty may carry an adrenaline injection to be administered in the case of anaphylaxis.
  • Usually the casualty will be able to inject themselves but if they are having difficulty you can help them to use it.
  • The different brands of auto-injector have slightly different instructions, but they are always clearly indicated on device.
  • Once the adrenaline is injected, they will usually recover very quickly.
  • If there has been no improvement within five to fifteen minutes, a second injection may be needed. Seek guidance from ambulance control if this is the case.


Learn more about Anaphylaxis on this video from Allergy UK


Richard Craddock

Richard is the Managing Director at SkillBase First Aid

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