Food allergy basics

What is a food allergy? 

A food allergy occurs when a person’s immune systems reacts to a food protein that is harmless for most people. When eaten, the immune system releases large amounts of chemicals that trigger symptoms that can affect a person’s breathing, heart, skin and gut. 

Some food allergies can be severe, causing potentially life-threatening allergic reactions known as anaphylaxis. 

Food allergy occurs in around 10% of infants, 4-8% of children aged up to 5 years and 2-3% of adults. 

The common allergy causing foods are peanut, tree nuts, egg, milk (dairy), sesame, crustacea, mollusc, fish, soy, wheat and lupin.  However, any food has the potential to cause an allergic reaction. 

There is no cure for food allergy – therefore avoidance of the food is essential to prevent reactions. 

Is a food intolerance the same as food allergy?

No. A food intolerance does not involve the immune system. It is the inability to digest a food which can cause discomfort and distress, but is not life-threatening.

Signs and symptoms of an allergic reaction to foods

ASCIA Action Plans provide information about when and how to give the adrenaline (epinephrine) autoinjector (e.g. EpiPen).  It is the go-to guide on how to manage an allergic reaction and should always be kept with the adrenaline autoinjector.

ASCIA Action plan anaphylaxis red personal 

MILD to MODERATE allergic reaction

  • Swelling of lips, face, eyes
  • Hives or welts
  • Tingling mouth
  • Abdominal pain, vomiting

Allergic reaction - man's back Allergic reaction on baby

SEVERE allergic reaction (anaphylaxis)

Watch for ANY ONE of the following

  • Difficult/noisy breathing
  • Swelling of tongue
  • Swelling/tightness in throat
  • Difficulty talking and/or hoarse voice
  • Wheeze or persistent cough
  • Persistent dizziness or collapse
  • Pale and floppy (young children)

Severe allergic in a man

Anaphylaxis usually occurs within minutes, up to 2 hours after exposure to the food. 

Mild to moderate signs may not always occur before anaphylaxis. 

This animation explains the signs and symptoms of an allergic reaction and what to do if someone has an allergic reaction.

Treating anaphylaxis

 It is important to lay the person flat – do not let them stand or walk.  If breathing is difficult, allow them to sit but not stand.

patient positioning for anaphylaxis

Prompt administration of adrenaline is the first-line treatment for anaphylaxis. Adrenaline (epinephrine) injectors contain a single dose of adrenaline and have been designed so that anyone in the community can use them in an emergency.

How to administer an adrenaline injector

More information about anaphylaxis is available from:

ASCIA website:

Allergy & Anaphylaxis Australia website:


Content updated July 2021

Latest News

Food allergy management videos 2 20207 April 2020

New video resources have been developed by the National Allergy Strategy to help parents, carers and people with allergies to select, prepare and store food safely.

COVID-19 Symptom Checker

COVID-19 Symptom Checker

A food allergy education project supported by

Allergy & Anaphylaxis Australia
National Allergy Strategy

The National Allergy Strategy is an initiative of the Australasian Society of Clinical Immunology and Allergy (ASCIA) and Allergy & Anaphylaxis Australia (A&AA), as the leading medical and patient organisations for allergy in Australia.

This project received funding from the Australian Government Department of Health.

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