Introduce your baby to all of the most common food allergens as soon as you start weaning (usually at around 6 months).
Food allergens are foods that can trigger allergic reactions. A food allergy is when the body's immune system reacts to specific proteins found in food.
Babies are not born with food allergies. Food allergies develop after birth.
They are more likely to happen if you delay introducing foods such as dairy, egg and peanut to their diet. This is often the case in babies with moderate to severe eczema.
Weaning and food allergies
When food allergies usually develop
Most food allergies affect children under age 3.
Many children can be helped to outgrow their milk and egg allergy by the time they start school.
Peanut and tree nut allergies can continue into adulthood.
Evidence shows that delaying introducing certain foods may increase the risk of developing an allergy to them.
Eczema and food allergies
Eczema is not a food allergy. But many children that had eczema as a baby will have a food allergy.
If your baby has eczema, it is even more important not to delay introducing food allergens.
This is because babies with eczema are at a higher risk of developing a food allergy. Introducing allergens to them early is even more important than for babies without eczema.
Types of food allergies
There are 2 main types of food allergies:
- immediate food allergy
- delayed food allergy
Each of these causes different symptoms.
Immediate food allergy
An immediate food allergy can start within minutes or up to 2 hours after eating a certain food. This type of allergy usually happens the first time your child eats the food.
Symptoms include:
- a sudden rash
- lip and face swelling
There can sometimes be vomiting, but this is usually along with a rash and swelling.
Vomiting on its own is not usually a sign of an allergic reaction.
Non-urgent advice: Contact a GP if:
- you think your child has symptoms of an immediate allergic reaction
Do not give them the food again until you have spoken with a GP.
Delayed food allergy
A delayed food allergy can take up to 24 hours to develop.
Symptoms include:
- tummy (abdominal) pain
- vomiting
- diarrhoea
- blood in your child's poo
A delayed food allergy is usually nothing to worry about. But you can talk to a GP if your baby's symptoms do not go away and are affecting their sleep or development.
This type of allergy is more common in young babies and children who are allergic to cows' milk or formula milk. Talk to a GP or public health nurse before changing your baby's formula.
A delayed food allergy is very rare in young babies and children with allergies to:
- fish
- shellfish
- peanuts
- tree nuts (such as almonds, brazil nuts, cashews, hazelnuts or walnuts)
Severe allergic reactions
Severe allergic reactions that affect your child's breathing or blood circulation (anaphylaxis) are also rare.
What foods to introduce
When you are introducing foods that could cause an allergy, start with:
- dairy products, such as milk or natural yogurt
- hard-boiled egg
- peanut (smooth peanut butter or finely crushed peanuts)
Then introduce (in any order):
- fish (remove all bones)
- sesame (finely crushed seeds or paste)
- tree nuts, such as almond, brazil, cashew, hazelnut, walnut (in a smooth paste or finely crushed)
- wheat, such as Weetabix, semolina and cooked pasta
How much food to give
When you introduce dairy, egg, nuts or fish for the first time, start with at least 1 teaspoon of the food.
Slowly aim to give them more each time until they eat a normal portion for their age.
It’s important to avoid the food getting on their skin, especially if they have eczema on their hands or face. Give your baby the food using a spoon.
Do not give your baby the spoon or food to hold themselves.
How to serve the foods
To introduce the food you can:
- give the food on its own
- add it into a purée
- mix it into another food that they are not allergic to
Ways to serve the food:
- dairy - use milk or natural yogurt
- egg - a mashed hard-boiled egg
- peanut - a heaped teaspoon of smooth peanut butter (no added sugar or salt) or 3 to 4 finely crushed peanuts
- other nuts - a smooth spread or blend of another type of nut
- fish - cooked fish that has no bones
How often to give these foods
Introduce each new food 1 at a time. For example, give egg to them 3 times in the same week.
You can also introduce other allergens in the same week. For example, introduce peanut another day that week.
When you have successfully introduced the food, continue to include it in their diet regularly.
Give them the food at least 3 times a week for the first 4 weeks, and then once a week afterwards. This will help their immune system to develop a tolerance.
If your child does not have an allergic reaction, these foods can be given on the same day.
Continue to include allergens in their diet as part of your normal family meals. Avoid leaving long gaps between eating the allergen.
If food allergies are common in your family
Introduce allergens into your child's diet even if your family has a history of food allergies. If your child’s sibling has a food allergy, you can still give your baby those food allergens.
Diagnosing a food allergy
Your GP will ask you some questions about your child's symptoms and their medical history.
If your GP thinks your child has a food allergy, they may:
- refer them to a children's or allergy clinic
- suggest you reintroduce food that you have been avoiding while you wait for their allergy clinic visit
Your child may need to have an allergy test.
Most children with a milk and egg allergy can start graded programmes before the test. These are known as the 'milk ladder' and 'egg ladder'.
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