Anaphylaxis following immunisation is extremely rare but can be life-threatening if not managed effectively. There are many conditions with similar presentations to anaphylaxis without being true anaphylaxis (eg. vasovagal, anxiety, vocal cord dysfunction) which can make the diagnosis difficult.
The Department of Health and the VicSIS network have put together Guidance for differentiating anaphylaxis from acute stress response for vaccine providers and Emergency Departments. This helpful resource provides a comparison of signs and symproms, as well as highlights the importance of measuring tryptase levels in patients with suspected anaphylaxis.
This guidance can be found in the resources section of the below reference page: