Medical Conditions
What are the signs of food allergies in babies?
Key points
- Most children will grow out of food allergies by 5-10 years of age.
- Know the signs of food allergy, especially anaphylaxis.
- If your baby is showing any signs of anaphylaxis soon after being given a new food, stop feeding your baby that food and seek medical advice immediately.
- Food allergies aren’t the same as food intolerances and management is different.
- Suspected allergy should always be confirmed by a clinical immunology/allergy specialist.
A food allergy is an abnormal immune reaction to a substance (allergen) in food that is normally harmless. Even tiny amounts of an allergen can cause an allergic reaction in individuals who have developed an allergy. Most reactions aren’t severe and deaths are extremely rare.
Food allergies can develop at any age but are most common in babies under 12 months. Food allergy affects 10% of children less than 12 months old, 8% of children up to five years of age and about 2% of adults. Anaphylaxis can be triggered by any food, but the most common triggers are egg, cow's milk, peanut, tree nuts, shellfish, sesame, soy, fish and wheat.

For information about managing confirmed food allergies see: ‘Tips for feeding a baby with established allergies’.
Most children will grow out of food allergies
The majority of food allergies in children are not severe and are usually 'outgrown'. Most children grow out of their food allergies by 5-10 years of age, especially children who are allergic to milk, egg, soy or wheat. The allergies more likely to persist into adulthood are to peanuts, tree nuts, fish and shellfish.
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Symptoms of food allergy
Mild to moderate symptoms of food allergy include:
- Swelling of the face, lips and/or eyes.
- Hives or welts anywhere on the body.
- Abdominal pain and/or vomiting.
Signs of a severe allergic reaction (anaphylaxis) to foods include:
- Difficult/noisy breathing.
- Swelling of the tongue.
- Swelling/tightness in the throat.
- Difficulty talking and/or hoarse voice.
- Wheeze or persistent cough.
- Persistent dizziness and/or collapse.
- Pale and floppy (in young children).
If you think your baby is having a reaction to food and there are signs of anaphylaxis, seek urgent medical attention.
If your baby is showing any signs of anaphylaxis soon after being given a new food, your baby could be having an allergic reaction. Stop feeding your baby that food and seek medical advice immediately. If your baby is having an anaphylactic reaction, lie them flat. DO NOT hold them upright. DO NOT allow your baby to stand or walk. If breathing is difficult, allow them to sit. If they are unconscious or vomiting, place them on their side.
If your baby is showing signs of a mild to moderate allergic reaction stay with your baby and watch to see if any signs of anaphylaxis develop. If so, seek medical attention immediately. If not, stop offering that food to your baby and discuss the reaction with your doctor. If you are not sure whether your baby is having a severe allergic reaction or not, it is better to seek urgent medical attention as anaphylaxis can be life-threatening. A mild or moderate allergic reaction can quickly progress to anaphylaxis, even in those who have only ever had mild reactions.
Symptoms of food allergy usually occur immediately in children, however, some are delayed.
Most food allergy symptoms in children occur within 30 minutes of ingesting a food, however, some symptoms of food allergy take longer to appear. Food allergy symptoms can occur 2-4 hours after eating a food. Symptoms of delayed-onset food allergies are usually less severe and not life-threatening. Most delayed reactions to food are more likely to be food intolerance.
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Food allergies aren’t the same as food intolerances.
Food reactions are classified as either: food allergy or food intolerance. Unlike food allergies, which are an immune response, food intolerances are reactions to food that do not involve the immune system and do not show up on allergy tests. Symptoms of food intolerances are usually less severe and not life-threatening.
The management of food allergies is different to food intolerances, so it is important to confirm with your doctor whether your child has an allergy or an intolerance. Any dietary restrictions or modifications should be discussed with your doctor, who may also recommend you see an Accredited Practising Dietitian and/or an allergy or immunology specialist for further checks and tests. For information about managing confirmed food allergies see: ‘Tips for feeding a baby with established allergies’. For current recommendations about allergy and introducing solids see: ‘Expanding the menu for your baby’.
Reliable diagnosis of food allergy and intolerance is essential for effective management.
To manage food allergies and intolerances effectively, an accurate diagnosis is essential. The type of testing or management depends on whether you have a suspected allergy or an intolerance. The results of allergy tests are a useful guide in determining whether a person is allergic, but they do not provide any indication about whether the reaction will be mild or severe and a supervised food challenge to confirm the results may be required.
Many unscientific and invalid testing methods have become available, including online allergy testing, that claim to test or treat food allergies and intolerances. Unreliable testing can result in misdiagnosis and ineffective management which can lead to potential harm and negatively impact on health and wellbeing. Some tests for food intolerances can lead to unnecessary food restrictions that cause nutritional problems and growth issues in children. Suspected allergy should always be confirmed by a clinical immunology/allergy specialist.
For information about managing confirmed food allergies see: ‘Tips for feeding a baby with established allergies’.
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Further support
If you are concerned about your child’s food intake, eating behaviours, growth or nutrition-related health, contact a GP, paediatrician or Accredited Practising Dietitian who can provide a comprehensive assessment that considers your child’s medical history, eating patterns including mealtime experiences, physical activity and genetic factors.
Find an Accredited Practising Dietitian with experience in infant and child growth - https://dietitiansaustralia.org.au/find-an-apd/
Resources for Families:
Australasian Society of Clinical Immunology and Allergy
www.allergy.org.au
Allergy and Anaphylaxis Australia
www.allergyfacts.org.au
Raising Children Network:
www.raisingchildren.net.au/guides/a-z-health-reference/food-allergies
www.raisingchildren.net.au/guides/a-z-health-reference/food-intolerances