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

About Anaphylaxis


Make sure you know about the symptoms of anaphylaxis so that you know when to use your Jext®. These symptoms can develop rapidly within minutes, or over a period of hours.

Only a few of the following symptoms may be present, however some can be life-threatening.

  • 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


If you experience any or all of these symptoms, it is time to use Jext® and call 999 in the UK, or 112 for Ireland, ask for an ambulance and say ‘anaphylaxis’.

Always use your medicine as you were instructed by your doctor.

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


Common food triggers are:


Tree nuts



Dairy products

Such as milk and eggs


Anaphylaxis can also be triggered by:


Most commonly
antibiotics, aspirin
or ibuprofen

Venom from stinging
or biting insects

Wasp and bee venom are the most common insect allergens. On rare occasions stings from hornets and bumble bees can also cause allergic reactions



Sometimes the cause may be unknown


Jext® contains a medicine called adrenaline. Adrenaline is the medicine of choice for first-line treatment of anaphylaxis because it works quickly to reverse the symptoms of an anaphylactic reaction.

When adrenaline is injected into the muscle of the thigh it acts quickly to constrict blood vessels, which helps to stop swelling around the face and lips, and relaxes the lungs, which improves breathing. Adrenaline also stimulates the heart, and helps raise lowered blood pressure.

The sooner the injection is given the better and you should seek professional medical assistance immediately after using your Jext®. You should be prepared to use a second Jext® after 5 -15 minutes if there is no improvement or if original symptoms return.

TreatmentEach 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®