Is it possible to predict anaphylaxis?

The short answer is no. Whether a person develops anaphylaxis at any one time depends on:

  • How much allergen has been ingested
  • Whether the allergen has been modified (i.e. for cow milk/egg the reactions tend to be more severe if it is uncooked vs baked)
  • The allergen itself (e.g. nuts and shellfish often cause more severe reactions)
  • The presence of asthma
  • If the individual is unwell with an infection or has been exercising prior to the onset of an allergic reaction (which can result in a more severe reaction)

This explains why sometimes a child may have a severe reaction at one time and then a milder reaction at another time.

The size of the skin test (in mm) or allergy blood test cannot be used to determine the severity of any future reaction.


As Allergists/Immunologists we consider many clinical factors when deciding if someone requires an adrenaline auto-injector, and these decisions can sometimes be complex. If you have been prescribed an adrenaline auto-injector make SURE

  • You know how to use it
  • It is in date and you have gone through the ASCIA action plan
  • USE it when your child has anaphylaxis