What is an allergenic food?

An allergenic food is a food that can trigger an allergic reaction in some people. Some people may say 'allergy food' but there are no foods that always cause an allergy.

If you have a food allergy, when you come in contact with the food that you're allergic to, your immune system reacts to it and causes the symptoms of an allergic reaction.

The most< common foods that cause allergic reactions are:

• eggs
• cow's milk
• peanuts
• tree nuts (almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios and walnuts)
• sesame
• soy

Some other common allergenic foods include:

• shellfish (including prawns, crab and lobster)
• fish
• wheat
• lupin

How common are food allergies?

Food allergies affect about 1 to 2 in every 20 children. Allergic diseases, including food allergies, have increased in recent years. It's not fully understood why.

Babies are more likely to develop allergies if there's a family history of allergic diseases (known as 'atopy') such as:

• eczema
• asthma
• hayfever
• food allergies

Babies with no family history of atopy can still get allergies, so the recommendations for introducing solid foods are the same for every family.

If you already know your baby has an allergic disease, talk to your doctor before introducing solids.

Are food allergy and food intolerance the same?

Food allergies and food intolerance are not the same.

An allergy involves the body's immune system and can be serious and life threatening.

An intolerance is a reaction that involves your gastrointestinal system (gut) not your immune system.

If you have a food intolerance, you may get unpleasant symptoms after eating the problem food, but you will not have a dangerous reaction.

A doctor can arrange allergy tests to diagnose any food allergies you may have. Food intolerances will not show up on these tests.

When should I start giving my baby allergenic foods?

You can introduce allergenic foods to your baby when you are introducing solids. This is usually when your baby is 6 months old, but not before 4 months old.

It was once recommended to avoid allergenic foods, but we now know it is important to introduce common allergenic foods to your baby before they turn 1 year old. This may lower their chance of getting an allergy later.

The first foods you give your baby should be foods that your family often eats, even if they can cause an allergic reaction for some people. It's important to give your baby foods that contain iron. This includes foods like peanut butter, cooked egg, dairy and wheat products that sometimes cause allergy.

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 how and when to introduce allergenic foods.

Should I continue to breastfeed when introducing allergic foods?

If possible, continue to breastfeed while you are introducing solids, as this may also lower the chances of allergies developing.

If you're not breastfeeding, give your baby a standard cow's milk based formula. Do not give them special hydrolysed infant formula or soy or goat's milk formula to try to prevent allergy.

How should I introduce allergenic foods?

It's best to try one new allergenic food at a time. This way, if your baby has an allergic reaction, it will be easier to find out which food caused it.

If your baby doesn't have an allergic reaction to the new food, keep giving it to them about twice a week. An allergy might happen if the food isn't given regularly after trying it.

Mix a small amount of the new food in with your baby's regular food. If your baby doesn't have a reaction, you can slowly give them more next time.

You can try a new allergenic food each day — but remember to keep giving your baby that food after you have introduced it to their regular diet.

Can I check the food is safe before my baby eats it?

If you want to check if a type of food is safe before your baby eats it, rub a small amount of the food on the inside of your baby's lip. If there is no reaction after a few minutes, then your baby can try eating it.

Don't rub food on your baby's skin. This will not show whether your baby will have an allergic reaction to it.

What time of day should I introduce allergenic foods?

Try introducing new allergenic foods during daytime meals soon after they wake. That way, if your baby has a reaction, you can monitor them more easily.

Which allergenic foods should I introduce first?

Start with the allergenic food you would like your baby to try first.

Remember that the food should be age-appropriate, such as:

• smooth food (pureed or mashed) from around 6 months old
• lumpy food and finger food from 8 to 9 months old
• cut up food from around 12 months old

A good place to start is with soft foods like a well-cooked egg or smooth peanut butter.

How can I tell if my baby is having an allergic reaction?

Symptoms of an allergic reaction usually occur within a few minutes but can take up to 2 hours to develop.

Mild-to-moderate reactions

Mild-to-moderate symptoms may include:

• hives or red welts (bumps) on the skin
• swelling of the lips, face or eyelids
• tingling in or around the mouth
• stomach pains
• vomiting
• diarrhoea

Your baby won't be able to tell you about their symptoms, but they may scratch at an area or slow discomfort.

If your baby has redness around their mouth, it's usually not an allergic reaction. Babies have sensitive skin that can be irritated by contact with some foods.

Speak to your doctor if you are worried about your baby's symptoms.

Serious allergic reactions

More serious symptoms can indicate a severe allergic reaction, known as anaphylaxis. Anaphylaxis is rare, but it is a medical emergency.

The symptoms of anaphylaxis may include one or more of the following:

• difficulty breathing or noisy breathing
• swelling of the tongue
• swelling of the throat — this can cause drooling
• hoarse voice
• coughing or wheezing
• looking pale
• collapsing or going 'floppy'

What should I do if my baby has an allergic reaction?

Anaphylaxis is life threatening. If your baby has any symptoms of anaphylaxis, call triple-zero (000) and ask for an ambulance. If your baby has an injection device containing adrenaline, such as EpiPen Jr or Anapen Junior, give them the injection immediately and then call the ambulance.

Anaphylaxis

1. Lie your baby flat, if possible. If they are having trouble breathing in this position, sit them up with their legs out.
2. If your baby has an injection device containing adrenaline, such as EpiPen Jr or Anapen Junior, give them the injection immediately into their outer mid-thigh with or without clothing. If your baby doesn't have an adrenaline device, call triple-zero (000) and ask for an ambulance immediately.
3. Call triple-zero (000) and ask for an ambulance.
4. If after giving the injection, your baby is still showing signs of anaphylaxis, give them a second dose.
5. If your baby becomes unresponsive or is not breathing start cardiopulmonary resuscitation (CPR).

Mild or moderate allergic reaction

If your baby has a mild or moderate reaction to a certain type of food:

• Stop giving them that food.
• Monitor them for symptoms of anaphylaxis.
• See your doctor for advice and an accurate diagnosis.

What can I do to prevent my baby having a food allergy?

There's no known way to prevent allergies, but you can try some things that might lower your baby's chance of having them:

• Introduce solids from 6 months of age.
• Introduce common allergenic foods before your baby turns one.
• If possible, breastfeed your baby until they are at least 6 months old and continue while introducing solids.
• Let your baby get dirty when they play to expose them to 'good' germs.
• Give your baby some safe sun exposure to increase their vitamin D levels.

What should I do if my baby is diagnosed with a food allergy?

If your baby is diagnosed with a food allergy, ask your doctor for advice and an action plan with instructions about how to treat an allergic reaction if it happens again.

Your doctor might refer you to an allergy specialist who may arrange allergy tests.

Don't cut out a major food, such as milk or wheat, without guidance from a health professional. This could lead to your child not getting the nutrients they need.

If your child needs to avoid certain foods, you can speak with a dietitian to make sure they still get everything they need to grow and develop.

Will my baby grow out of their food allergy?

Many children grow out of their food allergies, although others may be affected throughout their life.

Most children will outgrow allergies to:

• milk
• soy
• wheat
• eggs

Some allergies last for life, such as:

• peanuts
• tree nuts
• fish
• sesame
• shellfish

Resources and support

Speak to your doctor or child health nurse for more information on foods that can cause allergic reactions.

'Nip Allergies in the Bub' is an initiative from the National Allergy Strategy that has information for both parents and health professionals.

Learn more about allergies from the Australasian Society of Clinical Immunology and Allergy.

Read more about avoiding food allergies in babies from the Royal Australian College of General Practitioners.

Languages other than English

Health Translations has information about how to give an EpiPen and Anaphylaxis symptoms.