Common triggers for allergies and anaphylaxis

Triggers are substances that cause allergic or anaphylactic reactions. Triggers are specific to each person at risk; that means what makes one person react will not necessarily affect another person. Specific allergies are not inherited. So if shellfish are a trigger for your allergy, it does not mean your children will be the same. However, the tendency to be allergic does run in families. So your shellfish allergy may increase the risk of your children having another type of food allergy, or asthma, or eczema.

Almost any substance can be a trigger, but there are some that are quite common.

  • Food

    Food is a very common cause of allergies. In fact, one in 10 children born in Australia today will develop a food allergy.1 Hen’s eggs, cow’s milk, peanuts and tree nuts (e.g. almonds, macadamias) are the most common food triggers. Together with sesame, fish, shellfish, wheat and soy they cause 90% of allergic reactions.2

    Most food allergies are relatively mild, however, food triggers are still the most common cause of anaphylactic reactions. In people at risk, even very small amounts of food can cause a life-threatening reaction. Other people don’t even need to eat a particular food to react to it. Just smelling it, or touching it is enough to cause a reaction.

  • Insect bites and stings

    Being bitten or stung by an insect can trigger a life-threatening reaction in some people. Bee, wasp and jack jumper ant stings are the most common triggers in Australia. Ticks, green ants and fire ants can also trigger anaphylaxis.

  • Medicines

    Some medicines – whether your doctor prescribes them or you buy them from the chemist or supermarket – can trigger an allergy. Herbal and other alternative medicines can also cause reactions. You should not assume they are safe because they are ‘natural’. Speak to your doctor if you have had a reaction after taking any medication.

  • Latex

    Latex, or rubber, has been known to cause severe allergic reactions. People with latex allergies have been known to develop allergies to banana and avocado as well!

  • Unknown

    Sometimes, even with the best available tests it is not possible to identify the trigger for an allergy. However, you may still be able to identify patterns in your behaviour that commonly precede symptoms. You can then take steps to change that behaviour.

Your doctor can order tests that can help identify your triggers if you are not sure what they are.

1. Australasian Society of Clinical Immunology and Allergy (ASCIA). AIIDA report 2013. Available at Accessed 28 Nov 2013.
2. Allergy and Anaphylaxis Australia. What is anaphylaxis? Available at Accessed 28 Nov 2013.