Anaphylaxis and acute asthma

Anaphylaxis is a life-threatening condition and an important differential diagnosis in a patient presenting with acute respiratory symptoms. Identify and treat anaphylaxis early; the patient can deteriorate within minutes.

Sudden-onset shortness of breath and typical skin features (eg any of urticarial rash, erythema, flushing or angioedema) is diagnostic of anaphylaxis. Anaphylaxis should also be considered if a patient presents with sudden-onset shortness of breath and cardiovascular symptoms (eg dizziness, hypotension) or gastrointestinal symptoms (eg diarrhoea, vomiting), even if typical skin features are not present.

Note: Intramuscular adrenaline (epinephrine) is first-line treatment in suspected anaphylaxis.

If anaphylaxis is suspected or cannot be excluded, give empirical intramuscular adrenaline (epinephrine) according to national guidelines or local protocols; see here for links to Australian protocols.