Anaphylaxis

Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction.

Common identified causes of anaphylaxis:

• food (e.g. nuts) - the most common cause in children
• drugs
• venom (e.g. wasp sting)

Features

The Resus Council UK define anaphylaxis as:

• the sudden onset and rapid progression of symptoms
• Airway and/or Breathing and/or Circulation problems
• Airway problems may include:
  • swelling of the throat and tongue →hoarse voice and stridor
• Breathing problems may include:
  • respiratory wheeze
  • dyspnoea
• Circulation problems may include:
  • hypotension
  • tachycardia

This means that if there are no ABC problems then the patient is technically not having anaphylaxis.

Around 80-90% of patients also have skin and mucosal changes:

• generalised pruritus
• widespread erythematous or urticarial rash