Food allergies affect about 1 in every 20 children. But they are more common in infants younger than 12 months, affecting about 1 child in every 10 in this age group. Your health professional can advise you on when and how to introduce foods that might cause allergies.

What is an allergen?

An allergen is a substance that triggers an allergic reaction in some people. Allergic reactions to foods have increased over recent years. Nobody fully understands why.

Most allergic reactions are not severe. Many children grow out of some food allergies although others may continue to be affected throughout their life.

What are allergy foods?

The most common foods that could cause an allergy are:

• eggs
• cow's milk
• peanuts
• tree nuts (almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios and walnuts)
• sesame seeds
• soy
• shellfish (including prawns, crab and lobster)
• fish
• wheat
• lupin

Packaged foods must highlight any of these foods in their ingredients list. However, other foods can sometimes cause an allergic reaction too. Allergies to peanuts, tree nuts, seeds and seafood are most likely to last for life.

Are food allergy and food intolerance the same?

Food allergies and food intolerance are not the same — allergies involve the body's immune system whereas intolerance does not.

In someone with a food allergy, the body’s immune system reacts to the allergen as if it were foreign. The immune system then produces antibodies to fight the 'enemy' protein.

A doctor can arrange tests for various food allergies. Avoid unreliable tests. True food allergies can be serious and an accurate diagnosis is important.

A food intolerance is the body’s response to a substance in the food. The substance can be natural or added. The response, in someone with a food intolerance, may include headaches or stomach aches. Food intolerance is not life-threatening.

There are no specific tests for food intolerances.

When is the best time to introduce allergy foods?

The best time to introduce allergy foods is when you start introducing solids to your baby at about 6 months.

You can start by introducing a small amount of a type of food, then if there is no reaction, continue to give your baby that food as part of their regular diet.

It’s also best to try one type of food at a time to make it easier to identify what might cause a reaction.

Learn more here about how to introduce allergy foods.

Infant Feeding and Allergy Prevention Guidelines

The Infant Feeding and Allergy Prevention Guidelines have been developed by the Australasian Society of Clinical Immunology and Allergy to help guide parents and health professionals on the best time to introduce allergy foods.

It was previously recommended that allergy foods shouldn’t be introduced until after 12 months. However, further studies and research have shown that it is better to do so from 6 months.

How can you tell if your child has an allergic reaction?

An allergic reaction usually occurs within 30 minutes. Mild symptoms often include:

• hives or red welts (bumps) on the skin
• swelling of the lips, face or eyelids
• red rash around the mouth where the food has touched the skin
• tingling in the mouth
• tummy pains
• vomiting

If your baby does have a mild reaction to a certain type of food, don't give them that food again and see your doctor for an accurate diagnosis.

Serious symptoms can indicate anaphylaxis. Anaphylaxis is rare, but is a medical emergency. Symptoms include:

• difficulty breathing
• swelling of the tongue
• tightness in the throat
• a hoarse voice
• cough or wheezing
• collapsing or going 'floppy'

Anaphylaxis can cause a dangerous drop in blood pressure. If your child has any of the above symptoms, they require immediate and urgent action. Call triple zero (000) and ask for an ambulance.

More information

'Nip Allergies in the Bub' is an initiative from the National Allergy Strategy with the aim of providing information to both parents and health professionals.