Understanding the difference between a food allergy and a food intolerance in babies is super important when introducing new foods. While they can sometimes look similar, they involve very different reactions in the body.
What is a food allergy?
A food allergy is an immune system overreaction to a specific food protein causing symptoms like hives as well as life-threatening reactions such as breathing difficulty, dizziness, throat and tongue swelling, weak pulse and collapse. An allergic reaction can be triggered even when the smallest amount of food is consumed and can often begin within minutes of exposure.
What are the common symptoms of an allergic reaction?
Mild to moderate symptoms:
- Redness around the mouth
- Hives
- Vomiting shortly after eating
- Very fussy after eating
- Mild swelling of lips or face
If these symptoms occur stop exposure to allergen and seek medical advice before trying to offer again.
Severe symptoms – seek emergency medical care:
- Difficulty breathing
- Wheezing or persistent cough
- Swelling of the tongue
- Difficulty swallowing
- Pale and floppy
- Loss of consciousness
What is a food intolerance?
Rather than an immune response, intolerances occur due to difficulty digesting a food or a food component. Symptoms often depend on the amount eaten and can begin within hours or even days after food exposure and are not life threating.
What are the common symptoms of a food intolerance?
- Bloating
- Gas
- Diarrhoea
- Abdominal discomfort
- Sweats
What are the most common food allergens?
Around 90% of all food allergies come from the following foods. In the allergy world, we refer to them as the “Big 9”.
- Cow milk (and dairy products)
- Soy
- Peanut
- Wheat
- Shellfish
- Fish
- Sesame
- Tree nuts
- Eggs
How should allergens be introduced?
- One at a time so it is easy to identify if a reaction if it occurs.
- Early in the day so you can monitor for any reactions.
- Begin small, mixing some of the allergen into a food your baby already tolerates. For example, mixing some squished up hard-boiled egg into pureed avocado. Or a tiny bit of smooth peanut butter on some soldiers of toast.
- Never rub food into your baby’s skin. This will not help determine whether they have an allergy and due to most babies having sensitive skin it can cause irritation. Frequent skin contact with an allergen WITHOUT consumption of that allergen can increase risk of allergy developing.
Once I’ve introduced the allergen should I keep it in baby’s diet?
Yes, absolutely. It’s important to keep exposure frequent so baby’s immune system becomes familiar with the proteins in the food. It’s recommended that allergens be offered twice a week up until the age of 5 years old.
Why have allergy prevention recommendations changed?
The Australian Infant Feeding Summit was held in 2015 to review the guidelines surrounding infant feeding in Australia. Amongst the discussions at the summit were allergy prevention guidelines. Prior to 2015, all guidance was to strictly avoid common allergens and to use hydrolysed infant formula to prevent food allergies developing.
After acknowledging an abundance of research and sharing expert opinions, the guidelines shifted. It is now recommended that hydrolysed formula not be used with the goal of preventing food allergies, solids be introduced between 4 and 6 months (when baby is developmentally ready) and common allergen foods should be introduced during the first 12 months.
Common allergy myths
- Myth – Eliminating exposure to common allergens will stop an allergy developing
- Fact – Early exposure can help reduce development of allergies
- Myth – Using hydrolysed formula will stop an allergy developing
- Fact – Introducing the big 9 allergens early in your solids journey and using a milk protein formula (if appropriate) can aid in allergy prevention
- Myth – Every time a child has an allergic reaction, it will be worse than the last
- Fact – Reactions are unpredictable. The severity is determined by the amount of exposure to that specific food protein in addition to current health status (ie. infection or cold). It is not influenced by the severity of previous reactions.
- Myth – Just a little bit won’t cause a reaction
- Fact – Even the tiniest bit of an allergen can be life threatening
- Myth – You will have your allergy for life
- Fact – While some allergies can be life long, many children do outgrow their food allergies. Frequent testing under medical guidance is recommended.

