School Health Service

Anaphylaxis

Make sure you tell your school if you have anaphylaxis

  • If you need one, make sure that you have an in date Epipen on you and that you give your school a spare Epipen to be kept at school
  • Make sure that school staff are aware that you are at risk of an anaphylactic reaction to certain triggers. Your school nurse will discuss a care plan with you, your parents or carer and the school to make sure that the correct procedure is followed if necessary. It’s a good idea to tell your friends and classmates too.

What is anaphylaxis?

Anaphylaxis (pronounced ana-fill-ax-is) is a severe and potentially life-threatening allergic reaction affecting more than one body system such as the airways, heart, circulation, gut and skin.

Symptoms can start within seconds or minutes of exposure to the food or substance you are allergic to and usually will progress rapidly. On rare occasions there may be a delay in the onset of a few hours. 

What are the causes of anaphylaxis?

The common causes of anaphylaxis include foods such as, peanuts, tree nuts, milk, eggs, shellfish, fish, sesame seeds and kiwi fruit, although many other foods have been known to trigger anaphylaxis. Non-food causes include wasp or bee stings, natural latex (rubber), and certain drugs such as penicillin. In some people exercise can trigger a severe reaction – either on its own or in combination with other factors such as food or drugs, for example, aspirin.

What are the symptoms of anaphylaxis?

You may notice some severe symptoms such as a dramatic fall in blood pressure (anaphylactic shock). You may become weak and floppy and may have a sense of something terrible happening. This may also lead to collapse or unconsciousness.

In addition to those severe symptoms listed above, you may also experience: 

  • Widespread flushing of the skin
  • Nettle rash (otherwise known as hives or urticaria)
  • Swelling of the skin (known as angioedema) anywhere on the body.
  • Swelling of the lips
  • Abdominal pain, nausea and vomiting.

These symptoms can also occur on their own, without the more severe ones. Where that is the case, the reaction is likely to be less serious but you should watch carefully in case any of the more severe ones develop.

There are several different types of reaction which could occur:

Uniphasic

These come on quickly and symptoms get rapidly worse, but once treated, the symptoms go and don’t return.

Bi-phasic

These are reactions which may be mild or severe to start with, followed by a period of time when there are no symptoms, and then increasing symptoms with breathing and blood-pressure problems.

If you have an anaphylactic reaction, you will need an observation period in hospital after you have recovered in case you experience a biphasic reaction.

Most biphasic reactions occur within hours of the initial reaction but, rarely, they can be more delayed (Lee et al, 2015). On very rare occasions, a biphasic reaction has been known to occur as long as 72 hours after the initial reaction.

The length of the observation period would be for your treating doctor to decide. The National Institute for Health and Care Excellence (NICE) recommends that people who have had a severe allergic reaction should be monitored for six to 12 hours within a hospital setting because of the risk of a bi-phasic reaction. You are likely to be admitted to hospital at least overnight (NICE 2011).

Protracted anaphylaxis

This can last for several days and may need treatment in hospital for some time.

What is the treatment for a severe reaction?

Pre-loaded auto-injectors (sometimes referred to as ‘pens’ or Epipens) containing adrenaline are prescribed for people believed to be at risk of anaphylaxis. Adrenaline is referred to in some countries as epinephrine, which is the internationally recognised term for adrenaline.

What increases the risk of a severe reaction?

There are times when you may be particularly vulnerable and at increased risk of a severe reaction. Times when you need to be particularly careful to avoid the culprit allergen include:

  • If you have asthma that is poorly controlled
  • If you are suffering from an infection, or have recently had one
  • If you exercise just before or just after contact with the allergen
  • If you are also suffering from aeroallergen symptoms, such as hay fever
  • During times of emotional stress
  • If you have been drinking alcohol.

What to do in an emergency

If you or someone you know is having a severe allergic reaction, it is vital to receive an adrenaline injection. If they have their own adrenaline, this must be given as soon as a severe reaction is suspected to be occurring and an ambulance must be called immediately.

Practical points to follow if you are helping someone else, and to make sure your friends know what to do if you have an allergic reaction:

  • Try to make sure that the person suffering an allergic reaction remains as still as possible
  • Preferably they should be lying down and if they are feeling weak, dizzy or appear pale and sweating their legs should be raised
  • When dialling 999, say that the person is suffering from anaphylaxis (anna-fill-axis)
  • Give clear and precise directions to the emergency operator, including the postcode of your location
  • If adrenaline has been given, make a note of the time this was administered. A second dose can be given after five minutes if there has been no improvement
  • If the person’s condition deteriorates after making the initial 999 call, a second call to the emergency services should be made to ensure an ambulance has been dispatched
  • Send someone outside to direct the ambulance crew when they arrive
  • Try to ascertain what food or substance may have caused the reaction and ensure the ambulance crew knows this.