You’ve been dreaming about proper meals with your baby since their early feeds. The months after they begin complementary feeding are a joyful opportunity for your baby to become accustomed to all your family’s favourite foods, but it’s still important to be mindful of adverse reactions. Parents should also understand how allergies and intolerances differ and how they can be managed.

Food allergies

Allergies are an expression of the immune system's dislike for a particular food. The system registers a protein in this food as harmful and produces antibodies in response. A severe reaction can happen in minutes and even be life-threatening in severe cases.

Common allergens parents should be aware of include shellfish, fish, milk (and other dairy products), eggs, peanuts, tree nuts, and seeds.

The following symptoms may mean your baby has an allergy:

Breathlessness or difficulty breathing
A swelling of the lips, tongue, or throat
A rash or hives
Diarrhoea
Vomiting
Abdominal pain
Loss of consciousness

Your doctor can confirm whether your baby has an allergy and tell you how to manage and monitor it. They may recommend a food diary, an elimination diet, or allergy testing to determine the specific food allergen.

If your baby has a food allergy, it is important to avoid the offending food and carry an epinephrine auto-injector, if necessary, in case of a severe reaction outside of the home. You may also need to plan your baby's diet more carefully and go over food labels with a fine-tooth comb so that there is no chance the allergen is present in anything they eat. Make sure to research potential variant or brand-named forms of the allergenic food to keep your understanding of food label correct and up to date.

Food Intolerances

A food intolerance is unpleasant, occurring when your baby's body has difficulty digesting or metabolising a particular food. Intolerance can be triggered by simply increasing the amount of something your baby eats or drinks, whereas allergies can be triggered by even a little of the offending substance. The symptoms of intolerance are uncomfortable and disruptive. Unlike a food allergy, a food intolerance is not life-threatening, but it can still be a horrible experience.

Caffeine, lactose, gluten, additives, fructose, and some natural food chemicals are relatively common intolerances and may cause:

Abdominal pain, gas, or bloating
Diarrhoea or constipation
Nausea or vomiting

Ask your doctor about any suspected food intolerances. They may recommend tests or a special diet. A child with a lactose issue would need lactose-free formula and non-dairy alternatives, for example.

How to introduce allergenic foods

They should be introduced one at a time, with a gap of three days in between each new food, so that it is easier to identify any food that causes a reaction.

Start with a small amount of the new allergenic food, a quarter to half a teaspoon, and increase slowly.
Once your baby has had several attempts at eating the individual foods, you can start mixing them for variety.
Make sure your child is well at the time of introduction, i.e., not when they have a temperature, just had a vaccination, or have a cough or a cold.
It may be helpful to keep a food diary to track any potential reactions.
Data analysed by scientists from Imperial College London from 146 studies found that feeding children peanuts, between the ages of four and eleven months, may reduce risk of developing peanut allergy. This research was later published in the Journal of the American Medical Association in 2016.
There is some evidence that allergies can be genetic but even if another family member has a food allergy, you should still follow these guidelines. Take any necessary precautions to keep the food-allergic relative safe if they are eating with you and your baby.

Prevention

There is no evidence-based way to prevent food allergies and intolerances, but there are steps you can take to reduce your baby's risk. Some strategies include:

Breastfeeding: Breastfeeding has been shown to reduce the risk of food allergies and intolerances in babies.
Offering a variety of foods: Offering a variety of foods can help your baby develop a diverse gut microbiome, which may reduce the risk of food allergies and intolerances.

The AAP estimates that just 2% to 3% of babies who are exclusively breastfed show any signs of an allergic reaction to foods. According to Anaphylaxis UK, it is expected that the “trigger foods” mentioned in this article will all be tolerated without any issues in most babies. If you suspect that your baby has a food allergy or intolerance, contact your doctor for proper diagnosis and management.

Even a baby with an allergy or intolerance can enjoy a diverse diet that meets their nutritional needs. If an allergy or intolerance is identified, your doctor may also be able to offer guidance on other foods you should avoid or substitute.

Which foods might cause allergic reactions in babies?

From Unii’s Baby Nutrition Journey, we share what you need to know about food allergies and intolerances.