Differential diagnosis

Differential diagnosis includes (2):

• angio-oedema
• vasovagal episodes
• acute anxiety
• pulmonary embolism
• severe life-threatening asthma (3)
• hypoglycaemia
• seizures
• septic shock (3)

Medical and nursing staff can have difficulty distinguishing between anaphylactic reactions, convulsions and fainting. Most convulsions reported after measles and rubella vaccine occurred within one hour and had features uggesting syncope rather than epileptic fits. Syncope is common after any injection in adolescents and adults.

Very young children rarely faint - sudden loss of consciousness at this age should be presumed to be anaphylaxis unless there is a strong central (carotid) pulse, which persists during a faint or convulsion.

If in doubt, treat the patient for anaphylaxis.

Reference:

• (1) Immunisation Against Infectious Disease, HMSO, 1996
• (2) cks. national library of health. angio oedema and anaphylaxis
• (3) Emergency treatment of anaphylactic reactions.Guidelines for healthcare providers.Working Group of the Resuscitation Council (UK).2008