What is anaphylaxis?*
Anaphylaxis is the most severe form of allergic reaction and is potentially life threatening.
It must be treated as a medical emergency, requiring immediate treatment and urgent medical attention.
Anaphylaxis is a generalised allergic reaction, which often involves more than one body system (e.g. skin, respiratory, gastro-intestinal, cardiovascular). A severe allergic reaction usually occurs within 20 minutes of exposure to the trigger and can rapidly become life threatening.
What causes anaphylaxis?
Common triggers of anaphylaxis include:
Milk, eggs, peanuts, tree nuts, sesame, fish, shellfish, wheat and soy are the most common food triggers, which cause 90% of allergic reactions, however, any food can trigger anaphylaxis. It is important to understand that even small amounts of food can cause a life-threatening reaction.
Bee, wasp and ant stings are the most common causes of anaphylaxis to insect stings. Ticks and fire ants also cause anaphylaxis in susceptible individuals.
Medications, both over the counter and prescribed, can cause life threatening allergic reactions. Individuals can also have anaphylactic reactions to herbal or ‘alternative’ medicines.
Other triggers such as latex or exercise induced anaphylaxis are less common and occasionally the trigger cannot be identified despite extensive investigation.
Signs and symptoms
The signs and symptoms of anaphylaxis usually occur within the first 20 minutes to 2 hours after exposure. Rapid onset and development of potentially life threatening symptoms are characteristic markers of anaphylaxis.
Allergic symptoms may initially appear mild or moderate but can progress rapidly. The most severe allergic reactions involve the respiratory system (breathing) and/or cardiovascular system (heart and blood pressure).
Mild to moderate allergic reaction
- Tingling of the mouth
- Hives, welts or body redness
- Swelling of the face, lips, eyes
- Vomiting, abdominal pain
Severe allergic reaction- ANAPHYLAXIS
- Difficult/noisy breathing
- Swelling of the tongue
- Swelling or tightness in the throat
- Difficulty talking or hoarse voice
- Wheeze or persistent cough
- Persistent dizziness or collapse
- Pale and floppy (young children)
A person who is suspected of having a food allergy should obtain a referral to see an allergy specialist for correct diagnosis, advice on preventative management and emergency treatment. Those diagnosed with severe food or insect allergy must carry emergency medication as prescribed as well as an ASCIA Action Plan for Anaphylaxis signed by their doctor. Food allergic children who have a history of eczema and/or asthma are at higher risk of severe allergic reactions. Administration of adrenaline (epinephrine) is first line treatment of anaphylaxis.
Management & treatment
Anaphylaxis is a preventable and treatable event. Knowing the triggers is the first step in prevention. Children and caregivers need to be educated on how to avoid food allergens and/or other triggers.
However, because accidental exposure is a reality, children and caregivers need to be able to recognise symptoms of an anaphylaxis and be prepared to administer adrenaline according to the individual’s ASCIA Action Plan for Anaphylaxis.
Research shows that fatalities more often occur away from home and are associated with either not using or a delay in the use of adrenaline.
In Australia, adrenaline can be purchased on the PBS in the form of injectors. More information on prescription is available through ASCIA www.allergy.org.au.
The adrenaline (epinephrine) injectors (such as EpiPen®, Anapen®) are intramuscular injections that contain a single, pre-measured dose of adrenaline that is given for the emergency treatment of anaphylactic reactions. The devices are for use by lay people.
Please consult your doctor for more information on allergic reactions, accurate diagnosis and management strategies.
Food allergy basics
- A food allergy is an immune system response to a food protein that the body mistakenly believes is harmful. When the individual eats food containing that protein, the immune system releases massive amounts of chemicals, triggering symptoms that can affect a person’s breathing, gastrointestinal tract, skin and/or heart.
- Symptoms of food allergy can include; hives, swelling of the lips, face and eyes, swelling of the tongue, breathing difficulty, abdominal pain, vomiting or a sudden drop in blood pressure. If left untreated, these symptoms can be fatal.
- It is estimated that up to 2% of adults, 1 in 10 babies* and 6% of children have food allergy and some of them will experience a life-threatening allergic reaction (anaphylaxis).
- There are more than 170 foods known to have triggered severe allergic reactions. Examples include kiwi fruit, banana, chicken, mustard and celery.
- Currently, there is no cure for food allergy. Avoidance of the food is the only way to prevent a reaction.
- Adrenaline is the first line treatment for severe allergic reactions and can be administered via an injector.
- Food allergy is the leading cause of (severe reactions) anaphylaxis outside the hospital setting.
- Approximately 10 people die from anaphylactic reactions each year in Australia and some of these may have been triggered by food.
* Osborne et al. Prevalence of challenge-proven IgE-mediated food allergy using population-based sampling and predetermined challenge criteria in infants. J Allergy Clin Immunolol 2011; 127: 668-676
Permission is granted to make copies of this document for educational and awareness raising purposes only. Last updated May 2016