Introducing peanuts, eggs and other allergens to babies

Why early, and why regularly

Guidance changed after trial evidence showed that introducing peanut early to infants at risk substantially reduced the chance of developing peanut allergy, compared with avoiding it. Delaying allergenic foods is no longer recommended.

Offer allergenic foods from around six months, once a baby is taking solids and can sit with support — alongside other first foods, not before them.

Regularity is the part most families miss. Once introduced, keep the food in the diet — roughly a couple of times a week. Introducing peanut once and then not again for three months does not maintain the protection.

The main allergens to include are peanut, egg, cows' milk, wheat, soy, tree nuts, sesame, fish and shellfish. In India, sesame and peanut matter particularly, since both are everywhere in the everyday diet.

Introduce one new allergen at a time, a few days apart, and at home earlier in the day rather than at bedtime, so you can watch for a reaction while awake.

How to do it safely

Never whole nuts. Whole and chopped nuts are a serious choking hazard under five. Use smooth peanut butter thinned with warm water or milk, peanut powder stirred into porridge or dal, or finely ground nuts.

Egg: well cooked to start with — hard-boiled and mashed, or scrambled through. Raw and lightly cooked egg comes later.

Sesame: thin tahini stirred in, or til finely ground into food, rather than whole seeds.

Start tiny: a smear on the lip, wait a few minutes, then a quarter teaspoon, and build up over the meal if there is no reaction.

Do it when the baby is well. A day with a fever or a rash from something else makes any reaction impossible to interpret.

If your baby has severe eczema or an existing egg allergy, they are at higher risk of peanut allergy — talk to your paediatrician before the first introduction rather than doing it at home unsupported.

When to see a doctor

Call 108 or go to hospital immediately for any of: difficulty breathing, noisy breathing or wheeze, swelling of the lips, tongue, face or eyelids, a hoarse cry or trouble swallowing, widespread hives with pallor or floppiness, repeated vomiting with collapse, or a baby who becomes unresponsive. This is anaphylaxis, and it needs adrenaline and emergency care, not antihistamine at home.

See a doctor the same day for: hives that spread, vomiting shortly after a new food, or any reaction you are unsure about — and stop that food until you have been assessed.

See a paediatrician before starting allergens at home if your baby has severe eczema, an existing diagnosed food allergy, or a strong family history of anaphylaxis.

For delayed symptoms — persistent loose stools, blood or mucus in stool, worsening eczema, poor weight gain — see your doctor rather than eliminating foods on your own, which risks the diet without confirming the cause.

This article is general information, not medical advice, and is no substitute for personal medical advice. For any decision about your child's health, please consult your doctor.

Frequently asked questions