Introducing allergens during weaning

How do I introduce allergens?

Try to introduce a new allergen early in the day so you can watch out for any reactions for a few hours afterwards.

For example, if you start with cows’ milk, add a small amount of milk or plain yoghurt (just a quarter to a half of a teaspoon) to a veggie or fruit puree you’ve given your baby before and mix well before giving to your little one.

Remember, reactions can be immediate or delayed.

Keep an eye out for any reactions – check out the list below for some of the signs of an allergic reaction and what to do if your baby has one

How often should I offer allergen foods?

If your baby has no reactions, you can start to build up the amount of that allergen gradually.

Offer it regularly – at least once or twice a week.

Wait 2-3 days before introducing another allergen food like egg, soy or nuts.

Common allergen foods to try

During weaning, you can introduce these allergen foods one at a time:

• cereals containing gluten
• eggs
• fish (well cooked; avoid shark, swordfish and marlin)
• crustaceans like prawns and crab (well cooked)
• molluscs like mussels and oysters (well cooked)
• nuts (serve ground or as a nut butter)
• peanuts (serve ground or as a nut butter)
• soy and soy products
• celery
• celeriac
• cow's milk + dairy products
• mustard
• sesame seeds (served them crushed or ground)

If your little one has tried a new allergen food without a reaction, keep offering them regularly.

Chat to your health visitor or doctor about introducing allergens if you have a family history of allergies.

Signs of a food allergy

Signs of an immediate reaction

An immediate reaction, which usually occurs within 30 minutes of eating the food, may be mild, like:

• irritated or itchy skin rash (e.g. hives), especially around your baby's face
• swollen lips, face or eyes
• tummy pain or vomiting

If your baby has a reaction like this, don’t offer the allergen food again and dial 111 for advice or speak with your doctor.

If your baby has a swollen tongue, persistent cough, difficulty breathing or is pale, floppy or unconscious, dial 999 right away for help.

It’s important to note that not all allergic reactions are immediate and your little one may have a delayed-type food allergy, which may not cause symptoms for several hours after the food has been eaten.

Symptoms of a delayed reaction

• recurring tummy pains, vomiting or reflux
• food refusal
• loose and frequent poo (more than 6-8 times a day) or constipation (2 or less a week)
• skin reddening or itch all over the body
• worsening eczema (if present)

If your baby has a reaction like this, stop offering the food and wait for symptoms to subside (usually in a few days). Try offering the food again 1-2 weeks later and if symptoms re-occur, have a chat with your doctor.

If you are concerned at all about allergies or offering allergens, have a chat with your health visitor or doctor first.