clinical features

Last reviewed 01/2018

Anaphylaxis is likely when all 3 criteria are met:

  • sudden onset and rapidly progressing symptoms
  • life-threatening Airway , Breathing , Circulation problems
  • skin and mucosal changes

Early features of anaphylaxis include:

  • urticaria
  • pruritus
  • flushing

Established anaphylaxis is characterised by:

  • profound vasodilatation:
    • warm peripheries
    • low blood pressure
  • capillary leakage resulting in:
    • hypovolaemia
    • oedema e.g. face, pharynx and larynx
  • bronchospasm
  • gastrointestinal symptoms include abdominal pain, nausea and vomiting, incontinance

Death is due to circulatory collapse or respiratory failure.

Note:

  • skin or mucosal changes per se are not a sign of an anaphylaxis
  • skin and mucosal changes can be absent in up to 20% of anaphylaxis reactions
  • sometimes may have only a decrease in blood pressure

Reference: