Anaphylaxis

Anaphylaxis is a serious whole body allergic response to exposure to an allergen. It's an over-reaction by your immune system to the allergen trigger. It can make your airways tighten, which restricts your breathing, or affect the circulation of blood in your body, and it can be life threatening.

An allergen can be anything, but common triggers of anaphylaxis include:

• food
• insect venom
• medicines.

In some cases, the cause may take some time to be identified.

Food

• Milk, eggs, peanuts, tree nuts, sesame, fish, shellfish, wheat and soy are the most common food triggers, and cause 90% of allergic reactions. However, any food can trigger anaphylaxis.
• In some cases, mild or moderate  allergic symptoms can happen before the above symptoms, such as
• swelling of your face, lips or eyes
• hives, welts or body redness
• tingling of your mouth
• tummy pain or vomiting (being sick).
• Having asthma can also increase the risk of having a severe reaction if you accidentally eat even a small amount of the food you are allergic to.

Insect venom

Bee and wasp stings are the most common causes of anaphylaxis from insect stings in Aotearoa New Zealand.

Medicines

Both over-the-counter and prescribed medicines, such as antibiotics or painkillers, can cause life-threatening allergic reactions. You can also have anaphylactic reactions to herbal or alternative medicines. Anaesthetics and contrast agents used in imaging tests can also cause anaphylaxis.

Other causes

Other triggers such as latex or exercise-induced anaphylaxis are less common. Occasionally the trigger can't be identified.  

Anaphylaxis may be diagnosed following a severe reaction for which you went to an emergency department at the hospital. 

Your healthcare provider will ask you questions related to your symptoms, examine you and do some tests to find out your triggers, and/or rule out other conditions that can be similar to anaphylaxis, such as fainting, severe asthma attacks or panic attacks. 

Tests that may be done include:

• blood test to look for an antibody called IgE or an enzyme called mast cell tryptase
• skin prick testing to find out triggers.

You may also be diagnosed as at risk of anaphylaxis because of an allergy you have been diagnosed with e.g. to a food, even though you may only have had mild to moderate reactions to it previously. 

If you are diagnosed at risk of anaphylaxis, your doctor or nurse specialist will give you an anaphylaxis action plan(external link) that outlines the steps to take. They will also prescribe you an EpiPen (see below for more information). 

Anaphylaxis is a preventable and treatable event. Knowing the trigger(s) is the first step in prevention. Everyone at risk needs to know how to avoid food allergens and/or other triggers. 

However, because accidental exposure is possible, you and your child need to be able to recognise symptoms of anaphylaxis and be prepared to give adrenaline according to your anaphylaxis action plan.

How to position a child or an adult having a severe allergic reaction (anaphylaxis)

Please click the image below and scroll down on the new page to play the animation.

(external link)(external link)

(Australasian Society of Clinical Immunology and Allergy)

If you have had anaphylaxis for the first time, after those immediate steps and then getting emergency medical care, as part of your treatment plan you need to:

• see a specialist to find out your triggers 
• work out an anaphylaxis action plan(external link) with your healthcare provider
• attend follow-ups if required by your healthcare provider
• get educated on how to avoid triggers and use an adrenaline auto-injector if you are prescribed one
• ask your doctor or nurse specialist for an asthma management plan if you or your child also has asthma. 

The Australasian Society of Clinical Immunology and Allergy (ASCIA) provides free online training on anaphylaxis for patients, families and the community.(external link)(external link)

Adrenaline is the first-line treatment for anaphylaxis

Adrenaline is the treatment for anaphylaxis. Adrenaline works by quickly reversing the effects of anaphylaxis.

Adrenaline can be easily given using an auto-injector such as an EpiPen (the only one available in Aotearoa New Zealand). The auto-injector injects a single, pre-measured dose of adrenaline into your muscle. If you're at risk of anaphylaxis, then your healthcare provider might ask you to carry an auto-injector with you. Deaths from anaphylaxis are more common away from home and when adrenaline is either not used or is delayed.

If you or your child are prescribed an adrenaline auto-injector, it is important to learn and practise how to use it. You can register your EpiPen with My EpiPen(external link) and receive a free trainer pen.

Don't use antihistamines

Don’t use antihistamines to treat anaphylaxis – giving adrenaline quickly is the only treatment for anaphylaxis. Anaphylaxis is a potentially life threatening, severe allergic reaction and should always be treated as a medical emergency.

Once you have had an anaphylactic reaction you will be referred to a specialist to help you work out your triggers. This may involve allergy testing or food/drug challenge.

Knowing your triggers for anaphylaxis is essential. In many cases avoidance is the only way to prevent anaphylaxis. Your specialist will help you work out ways to reduce the risk of anaphylaxis. This usually includes writing up an emergency anaphylaxis action plan. You will need to have regular reassessment, to check if the allergy is still present and to make sure your prevention plan is working for you.

Carrying your adrenaline auto-injector with you at all times if you have one and using it if you think you may have anaphylaxis can also help to prevent your anaphylaxis from getting worse.

It can be frightening if you have anaphylaxis. Talk through your feelings with your family/whānau members or health professionals taking care of you. Read more about how to talk about your feelings. 

Below are some support services and information for people affected by anaphylaxis and their family/whānau:

Allergy NZ(external link)Check their website or phone 0800 34 0800 for information and support. 
EpiPen(external link) Online educational resource where you can access additional information about anaphylaxis and EpiPen®.

An action plan for anaphylaxis provides a course of action to follow in the event of an allergic reaction, which is often due to food allergy or insect stings. Susceptible people and their families should be able to recognise the symptoms of anaphylaxis and know in advance what to do in an emergency.

A copy of your Anaphylaxis Action Plan, filled in and signed by your doctor or nurse specialist, should be kept with your EpiPen and taken with you wherever you go. A copy should be given to your child’s early childhood centre or school, or kept at your workplace.

Anaphylaxis action plans are produced by the Australasian Society of Clinical Immunology and Allergy (ASCIA) and are updated regularly. Your doctor or nurse specialist should review these regularly with you. Go through these action plans with your healthcare providers and ask any questions if you are unsure.​

Action plan for EpiPen

ASCIA action plan for anaphylaxis (red) 2023 EpiPen®(external link) – for people with allergies who have been prescribed EpiPen® adrenaline auto-injectors. 

Action plan poster for EpiPen general use

ASCIA first aid plan for anaphylaxis (orange) 2023 EpiPen®(external link) – for use as a poster or to be stored with general use EpiPen® adrenaline auto-injectors. 

General anaphylaxis action plan 

ASCIA action plan for anaphylaxis (red) 2023 generic(external link) – for people with allergies who have been prescribed any brand of adrenaline auto-injectors. 

Action plan poster for general anaphylaxis

ASCIA first aid plan for anaphylaxis (orange) 2023 generic(external link) – for use as a poster or stored with general use adrenaline auto-injectors. 

Action plan for allergic reactions

ASCIA action plan for allergic reactions (green) 2023(external link) – for people with allergies who haven't been prescribed adrenaline auto-injectors. 

First aid treatment for anaphylaxis

Anaphylaxis is a severe allergic reaction and potentially life threatening. It should always be treated as a medical emergency, requiring immediate treatment.

Information in:

• te reo Māori(external link) 
• Samoan(external link) 
• Tongan(external link)

For more information, visit ASCIA Action plans and first aid plans for anaphylaxis(external link).