This website has been developed and funded by ALK and is intended for children who have been prescribed Jext ®, their parents and carers.


All allergic reactions are caused by the immune system in the body. The immune system’s job is to fight off things that could make a person ill.

However, in some people the immune system makes mistakes and thinks that a type of food or another substance is harmful. The body starts to fight off this substance or allergen – and the person has an allergic reaction.

Sometimes, an allergic reaction causes annoying things like itchiness or a runny nose. But sometimes, it can cause more serious problems like a ‘puffy’ face, a swollen tongue, and finding it hard to breathe. This severe type of an allergic reaction is called an anaphylactic reaction.

About Anaphylaxis

Symptoms of anaphylaxis

The symptoms which warn that an anaphylactic reaction is starting are listed below.

  • Itching of the skin
  • Raised rash (like a nettle rash)
  • Flushing
  • Swelling of the lips, throat, tongue, hands and feet
  • Wheezing, hoarseness, shortness of breath
  • Nausea, vomiting and stomach cramps
  • In some cases, loss of consciousness

You may have only a few of the symptoms, however some of them can be very serious.

Know the symptoms

Make sure you know what these symptoms are so that you know when you need to use your Jext®. These symptoms can develop very quickly, within minutes, or more slowly.

It is important to remember that the pattern of symptoms you experience may be different from previous reactions.



If you experience any or all of these symptoms you should:

  • Call for help
  • Use your Jext®, or ask someone else to give it to you
  • Use a phone to dial 999 in the UK, or 112 in Ireland, ask for an ambulance and say ‘anaphylaxis’ – or ask somebody else to make the call


It is important that you and your grown up know which thing or things caused you to have an
allergic reaction in the past. This is because you must try to avoid having a reaction again in
the future…


Tree nuts



Dairy products

Such as milk and eggs


Anaphylaxis can also be triggered by:


Such as antibiotics

Wasps or bee


Such as rubber


Sometimes the cause may be unknown

Jext® adrenaline auto-injector

A doctor has given you Jext® because your body reacted badly to something in the past, such as a type of food or an insect sting. In other words, you had an allergic reaction to something.

Jext® contains a liquid called adrenaline. This is a medicine which Jext® injects into your body. It works quickly to reverse the symptoms of an anaphylactic reaction, whilst you wait for an ambulance. Jext® is easy to use, and you won’t see the needle going into your body.

If you don’t feel any better within 5-15 minutes of using Jext®, you may need to use a second Jext®.

Each Jext® can only be used once. It is recommended you carry two Jext® in case you do need a second dose.

How to use Jext®