Anaphylaxis is a severe and potentially life-threatening hypersensivity reaction.1 The hypersensitivity reaction may be generalised or systemic and tends to occur within minutes.
Anaphylaxis can be an allergic reaction that is immunologically mediated, or a non-immunologically mediated response, or idiopathic.2 Allergic anaphylaxis in relation to food triggers, wasp or bee stings (venom) and latex is immunologically mediated, but anaphylaxis caused by medications is not.1 Most anaphylactic reactions are idiopathic: a trigger is not identifiable from the history.
Anaphylaxis presents with airway compromise as a result of pharyngeal and/or laryngeal oedema and breathing difficulty. The latter is caused by an increased respiratory rate and/or bronchospasm.
There may be evidence of circulatory compromise, such as hypotension and an increased heart rate. Skin and mucosal changes are present in most cases; possible skin changes include flushing and urticaria. Symptoms can deteriorate rapidly.
Incidence and causes