Recognising fainting versus anaphylaxis

We understand for many people, such as Pharmacists, that dealing with a medical emergency can be very daunting and they may feel worried about making the right diagnosis and therefore give the correct treatment.

Within our vaccine training courses we cover the difference between fainting and anaphylaxis as there is more likelihood that they would experience a patient fainting after their injection, rather than having an anaphylactic reaction. However, both initially will be alarming to the Pharmacist, or person dealing with the situation.

We have devised a simple chart to compare signs and symptoms of both and we hope you find it useful.

Fainting is relatively common when vaccinating adults and adolescents but rare in infants and children.   Sudden loss of consciousness in young children should be presumed to be an anaphylactic reaction, especially if a strong central pulse is absent.

The table below demonstrates the differences

Signs or Symptoms




Rapid, sudden onset and progressive life threatening condition


Usually gradual but can be sudden



Swelling to lips, tongue, throat & stridor



Shortness of breath, wheeze



Pale, clammy, low blood pressure, rapid pulse

Pale, clammy, low blood pressure, slow pulse


Confused, agitated, sense of impending doom, loss of consciousness

Dizziness, nausea, temporary loss of consciousness with rapid recovery


Swelling, general red rash, raised itchy rash

Normal, but possibly pale and clammy

Course of Action


Position patient, reassure and monitor


Administer Adrenaline 1:1000 as per local policy and repeat after 5 mins if there is no improvement.

Lay patient on their back with legs raised. Monitor recovery and allow them to sit up on their own time.

 Make sure that you have received training on how to use the auto-injectors of adrenaline and that you have annual anaphylaxis training, whether it is face to face or online. Training will help you to prepare yourself in how to confidently deal with an emergency situation

Written by Jane Lambert 12th April 2017