Introducing Allergens to Babies: Eggs, Peanuts and Other Common Allergens
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Common allergenic foods such as eggs and peanuts can usually be introduced from around 6 months, once your baby is ready for solid foods. NHS guidance recommends introducing foods that can trigger allergic reactions one at a time and in very small amounts so that you can identify a reaction more easily.
If your baby tolerates an allergenic food, the NHS advises continuing to include it as part of their usual diet. There is no need to avoid common allergens simply because they can cause reactions, unless a healthcare professional has advised you to do so.
It is understandable to feel more nervous offering peanut or egg than a spoonful of mashed potato. Knowing which foods are common allergens, how to introduce them safely and what signs of an allergic reaction can look like can make the process feel more manageable.
When can you introduce allergens to a baby?
The NHS advises that foods that can trigger allergic reactions can be introduced from around 6 months, alongside other foods.
Before starting solids, look for the usual developmental signs of readiness. According to the NHS, these signs should appear together. Your baby should be able to:
- stay in a sitting position and hold their head steady
- coordinate their eyes, hands and mouth so they can look at food, pick it up and bring it to their mouth
- swallow food rather than automatically pushing it back out
If you are considering introducing solid foods before around 6 months, speak to your health visitor or GP first.
Some babies may also need individual advice about allergens before they begin, particularly if they already have eczema or a diagnosed food allergy.
Which foods commonly cause allergic reactions?
According to the NHS, foods that can trigger an allergic reaction include:
- cow’s milk
- eggs
- foods containing gluten, including wheat, barley and rye
- nuts and peanuts
- seeds
- soya
- shellfish
- fish
These foods can still form part of a baby’s diet when introduced appropriately.
The NHS recommends introducing them one at a time and in very small amounts. Doing this makes it easier to identify which food may have caused a reaction if symptoms appear.
Once your baby has eaten an allergenic food without a reaction, keep offering it as part of their usual diet.
How to introduce an allergenic food
Keep the first introduction simple.
Choose one allergenic food and offer a very small amount in a form that is appropriate for your baby’s stage of eating.
Avoid introducing several new allergens together in the same meal. If your baby reacts, it may otherwise be difficult to know which ingredient was responsible.
For example, rather than introducing egg, peanut and yoghurt for the first time together, introduce them separately.
Make sure your baby is sitting safely upright and stay with them while they eat, as you should for every meal.
You do not need to make the experience dramatic or turn it into a test. The aim is simply to introduce the food in an age-appropriate form while being aware of possible symptoms.
How to introduce egg to a baby
Egg is one of the foods that can cause an allergic reaction, but it can be introduced from around 6 months alongside other solid foods.
The NHS advises that hen’s eggs carrying the British Lion mark can be eaten raw or lightly cooked by babies and children. Eggs that do not have the British Lion mark, or are not produced under an equivalent food safety scheme, should be cooked thoroughly.
For a baby starting solids, egg needs to be prepared in a texture they can manage.
Depending on how you are feeding, appropriately prepared egg might be offered mashed, mixed into another familiar food or as a suitable soft finger food.
Introduce a very small amount initially and avoid combining it with several other new allergenic foods.
If your baby tolerates egg, continue including it in their diet.
How to introduce peanuts to a baby
Peanuts can also be introduced from around 6 months in an appropriate form.
Whole peanuts and other whole nuts should never be given to babies. The NHS advises that whole nuts should not be given to children under 5 because of the risk of choking.
For babies, peanuts can be offered crushed or ground, or as a smooth peanut butter prepared in a suitable way.
Do not offer a whole nut or a large lump of thick nut butter, which can be difficult for a baby to manage safely.
As with other allergens, start with a very small amount and introduce peanut separately from other new allergenic foods.
If your baby tolerates peanut, NHS guidance recommends continuing to include it in their usual diet.
What if your baby has eczema?
If your baby has eczema, speak to your GP or health visitor before introducing foods that can trigger an allergic reaction.
NHS guidance specifically advises parents to seek medical advice if their baby has eczema, a diagnosed food allergy or a family history of food allergies, eczema, asthma or hay fever.
This does not necessarily mean your baby will be unable to eat common allergens.
It means individual advice can be helpful because your baby’s circumstances may affect how allergenic foods should be introduced.
Do not remove major food groups from your baby’s diet without discussing it with an appropriate healthcare professional.
What if there is a family history of allergies?
A family history of food allergy or other allergic conditions is another reason to discuss allergen introduction with your GP or health visitor.
Tell them about the relevant family history and ask whether your baby needs any specific guidance before trying common allergens.
Try not to assume that your baby will have the same allergy as a parent or sibling.
Equally, do not deliberately avoid allergenic foods for a prolonged period without professional advice. The NHS states that delaying the introduction of peanut and hen’s egg beyond 6 to 12 months may increase the risk of developing an allergy to these foods.
If your baby is at higher risk, personalised guidance is more useful than trying to interpret general feeding rules yourself.
What does a food allergy reaction look like?
Allergic reactions can affect different parts of the body.
The NHS lists possible symptoms including:
- a red, itchy rash
- swelling of the lips, face and around the eyes
- vomiting
- diarrhoea
- coughing
- wheezing
- a runny or blocked nose
- red, itchy or watery eyes
Symptoms can occur quickly after eating a food, although some reactions can take longer to appear.
If you think your baby has reacted to a food, stop giving that food and seek medical advice.
It can be useful to remember what your baby ate and what symptoms appeared so you can explain this clearly to a healthcare professional.
When is an allergic reaction an emergency?
A severe allergic reaction, known as anaphylaxis, is a medical emergency.
Call 999 if you think your baby is having a severe allergic reaction.
NHS guidance describes emergency symptoms that can include swelling of the throat or tongue, difficulty breathing, very fast breathing, difficulty swallowing, blue, grey or pale skin, lips or tongue, sudden confusion or unusual drowsiness, dizziness, fainting, or a baby becoming limp or not responding as usual.
On brown or black skin, changes in colour may be easier to see on the palms of the hands or soles of the feet.
Do not wait to see whether severe symptoms improve on their own.
Food allergy or food intolerance?
Food allergies and food intolerances are not the same thing.
A food allergy involves the immune system and can sometimes cause a serious reaction.
Food intolerance does not involve the immune system in the same way and does not cause anaphylaxis.
Symptoms alone are not always enough for a parent to determine what is happening, particularly in a baby. If your baby repeatedly develops symptoms after eating a particular food, speak to your GP rather than diagnosing an allergy or intolerance yourself.
A healthcare professional can advise whether further assessment is needed.
Should you avoid allergens to prevent an allergy?
Do not routinely exclude common allergenic foods from your baby’s diet unless a healthcare professional has advised you to.
The NHS recommends introducing foods that can trigger allergic reactions from around 6 months, one at a time and in very small amounts.
It also advises that once these foods have been introduced and tolerated, they should remain part of your baby’s usual diet.
For peanut and hen’s egg specifically, the NHS states that delaying introduction beyond 6 to 12 months may increase the risk of allergy.
If your baby has eczema, an existing food allergy or other factors that make you concerned about allergy risk, speak to your GP or health visitor about the timing and method of introduction.
Do you need to introduce allergens in a particular order?
NHS guidance focuses on introducing allergenic foods one at a time and in very small amounts rather than prescribing one compulsory order for every baby.
This gives you flexibility.
You might introduce egg as one of your baby’s early foods and peanut at another meal once your baby has already tried some other foods. Another family may do this differently.
The useful part is being able to identify the food your baby has eaten if a reaction occurs.
Once an allergen has been introduced without a reaction, continue to offer it regularly as part of your baby’s usual varied diet.
Can babies have cow’s milk as an allergen?
Cow’s milk is a common allergen and can be introduced in food from around 6 months.
The NHS says pasteurised cow’s milk can be used in cooking or mixed with food from around this age.
However, cow’s milk should not be given as your baby’s main drink until they are 12 months old. Breast milk or first infant formula should remain the main drink during the first year.
Pasteurised full-fat plain yoghurt and pasteurised cheese can also be offered from around 6 months.
If you suspect your baby reacts to cow’s milk, speak to your GP or health visitor before removing dairy or changing their milk feed.
What about gluten, fish, soya and sesame?
Other common allergens can also be introduced from around 6 months in suitable forms.
Foods containing gluten include wheat, barley and rye. Soya can appear in foods such as tofu and soya-based products. Fish should be carefully checked for bones and prepared in a texture your baby can manage.
Sesame is another common allergen and may appear in foods such as tahini.
Introduce each new allergen separately and in a very small amount, following NHS guidance.
Some foods have additional safety considerations beyond allergy. Raw shellfish, for example, should not be given to babies because it can increase the risk of food poisoning.
Always prepare food according to current NHS food safety and choking guidance.
Keep allergen introduction practical
You do not need to introduce every allergen within a few days.
Starting solids already involves plenty of new tastes, textures and routines. Work through common allergenic foods in a way that allows you to introduce them individually and recognise any reaction.
A simple approach is:
- Choose one allergenic food.
- Prepare it in an age-appropriate form.
- Offer a very small amount.
- Avoid introducing several new allergens at the same time.
- Watch for symptoms of an allergic reaction.
- If the food is tolerated, keep it in your baby’s usual diet.
If you are worried because your baby has eczema, an existing allergy or a relevant family history, get professional advice before introducing allergenic foods.
There is no benefit in making these first tastes frightening for yourself. Being prepared, following recognised guidance and knowing when to seek help is enough.
When to get professional advice
Speak to your GP or health visitor before introducing common allergenic foods if your baby has eczema, a diagnosed food allergy, or if there is a family history of food allergies, eczema, asthma or hay fever.
Seek medical advice if your baby develops symptoms after eating a particular food or repeatedly seems unwell after the same food.
Do not diagnose an allergy yourself or remove important foods from your baby’s diet for a prolonged period without professional guidance.
Call 999 immediately if you think your baby is having a severe allergic reaction. Difficulty breathing, swelling of the throat or tongue, becoming limp or unresponsive, or other signs of anaphylaxis require emergency medical help.