Anaphylaxis
8-minute read
If you think you or someone you know is experiencing anaphylaxis, use the adrenaline autoinjector immediately. Then call triple zero (000) and ask for an ambulance. Follow an ASCIA allergy action plan, if you have one.
Key facts
- Anaphylaxis is a severe, life-threatening allergic reaction.
- It can happen after exposure to triggers, such as foods, bites, stings or medicines.
- Severe symptoms include airway swelling, difficulty breathing and a sudden drop in blood pressure.
- If you think someone is having anaphylaxis, use an adrenaline autoinjector (if available), call triple zero (000) and ask for an ambulance.
- People with a known allergy should carry an adrenaline autoinjector and an action plan to manage anaphylaxis.
What is anaphylaxis?
Anaphylaxis is a severe type of allergic reaction.
It can happen after exposure to triggers, such as:
- — commonly , , and
- — such as, bee stings, and
- some medicines
Anaphylaxis can develop quickly and can be fatal. It should be treated as a .
If anaphylaxis progresses, it can lead to a dangerous drop in . This is known as 'anaphylactic '.
What are the symptoms of anaphylaxis?
Anaphylaxis symptoms can vary, but often affect breathing, the throat and other body functions. Symptoms of anaphylaxis can include any of the following:
- difficulty talking and hoarse voice
- a swollen tongue
- persistent or
- swelling or tightness in the throat
- pale and floppy (in young children)
- wheeze or persistent cough
Sometimes, mild to moderate symptoms may happen before anaphylaxis. Symptoms may include:
- swelling of face, lips and eyes
- skin changes such as or welts
- or
Watch this video from to learn how to recognise signs and symptoms of an allergic reaction.
When should I call an ambulance or go to the emergency department?
If you think you or someone you know is experiencing anaphylaxis, use the adrenaline autoinjector immediately. Then call triple zero (000) and ask for an ambulance. Follow an ASCIA allergy action plan, if you have one.
What should I do while waiting for an ambulance?
- Lay the person flat and keep them still — do not let them stand or walk.
- If the person is , place them in the .
- If breathing is difficult or they are vomiting, allow them to sit with legs outstretched.
- Use an , if you have not already done so.
- If their symptoms persist 5 minutes after the first injection, you should inject another adrenaline autoinjector.
Watch this video from to see how to position a child or an adult having a severe allergic reaction.
If the person is unresponsive and not breathing normally, start .
If you are not sure — always use the adrenaline autoinjector. It is better to use it than delay treating a serious reaction. Adrenaline does not have serious side effects if given unnecessarily, but can be lifesaving. If the person also has , give the adrenaline autoinjector first. Then give .
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What causes anaphylaxis?
Anaphylaxis is triggered by the when it recognises a harmless substance as 'dangerous' (allergen).
The symptoms of an allergic reaction vary from person to person. They also depend on the type of allergen and how it entered the body. It may enter the body for example through ingestion, skin contact or inhalation.
This immune response can affect many different body systems, such as your:
How is anaphylaxis diagnosed?
Anaphylaxis is diagnosed by looking at your symptoms and checking your medical history. Your doctor may also to confirm the diagnosis.
Anyone who has had or may have had anaphylaxis should ask their GP for a to an allergy specialist. This specialist can:
- give advice on avoiding future reactions
- explain what to do if another allergic reaction happens
ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.
How is anaphylaxis treated?
Anaphylaxis requires immediate treatment with . Treatment involves quick, supportive care and positioning. You should lie flat to help blood flow and avoid walking or standing until you are stable.
In hospital, you may also receive oxygen and fluids through a vein if needed. After treatment, you will be checked for at least 4 hours. This is to check for any return of symptoms or complications.
Follow the steps on your . Be aware of your position and as directed.
What are the complications of anaphylaxis?
It is important to act quickly to help reduce your chance of complications. Untreated, anaphylaxis can quickly lead to:
- life-threatening low blood pressure (anaphylactic )
- death
Can anaphylaxis be prevented?
People with diagnosed allergies should avoid all triggers and confirmed allergens.
If you have an allergy, you should always carry:
- an (if prescribed)
- an
It's a good idea to ensure your friends and family know how to follow your anaphylaxis action plan in case you need help. Wearing a medical ID bracelet or necklace can also help others recognise and respond to the emergency.
Resources and support
- (ASCIA) has information on allergies and anaphylaxis, including setting up a .
- provides information, resources and support for people living with allergies, their families and communities.
- offers resources for people living with food allergies and those who support them.
You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.
Other languages
- The (ASCIA) provides .
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This information was originally published on healthdirect -
Last reviewed: November 2024