Offer common allergy foods early and keep offering them. Current Australian advice from ASCIA's guide to introducing solid foods, updated in 2026, is to start solids when your baby is ready, usually around 6 months and not before 4 months. Include well-cooked egg and peanut soon after solids start, and introduce all the common allergy foods in the first year (by 12 months). Delaying them has been shown to raise the chance of food allergy.
Introduce one new allergen at a time, start with a small amount, and once a food is tolerated keep it in your baby's diet at least once a week. This guide explains how to do it, how to spot a reaction, and what to do if one happens.
When should I introduce allergens to my baby?
The three main guidelines agree on the direction — early, not delayed — but differ a little in detail.
| Guidance | When to start | If your baby has eczema or allergy |
|---|---|---|
| ASCIA (Australia and NZ) | Egg and peanut soon after solids start; all common allergens by 12 months | Still introduce in the first year |
| NHS (UK) | From around 6 months, one at a time | Talk to your GP first |
| AAP (US) | Once a few first foods are tolerated | Severe eczema: see your paediatrician first; peanut ideally from 4 to 6 months |
The NHS guide to food allergies in babies says delaying peanut and hen's egg beyond 6 to 12 months may increase the risk of allergy to them. The AAP's allergen guide on HealthyChildren.org suggests starting allergy foods after your baby has managed a few lower-risk first foods.
For signs your baby is ready for solids at all, see starting solids.
Which foods are the common allergens?
ASCIA lists the foods behind most allergic reactions in babies:
- cow's milk (for example yoghurt, cheese, or milk in cooking)
- egg
- peanut
- tree nuts, such as cashew and walnut
- wheat
- soy
- sesame
- fish
- shellfish
The NHS list also includes foods containing gluten (such as barley and rye), beans, lentils and peas, celery, mustard and sulphur dioxide. Other foods can cause reactions too, but these cause most of them.
Cow's milk is fine in food from around 6 months, but it shouldn't replace breast milk or formula as your baby's main drink before 12 months. See foods to avoid for that and other first-year rules.
How do I introduce egg and peanut safely?
ASCIA recommends well-cooked whole egg, such as mashed hard-boiled egg. For peanut, use smooth peanut butter or paste, peanut powder or finely ground peanut, never whole nuts or pieces, which are a choking risk. The AAP suggests thinning a small amount of peanut butter into cereal, pureed fruit or yoghurt.
ASCIA gives this step-by-step guide:
- Pick a good time. Offer the new food when your baby is well, and when you can watch them for the next couple of hours. ASCIA says allergic reactions usually happen within minutes to two hours.
- Start small. Mix about 1/4 teaspoon of the egg or peanut into food your baby already eats, such as a vegetable puree. If you like, first place a little inside your baby's lip and wait a few minutes.
- Build up. If there's no reaction, offer about 1/2 teaspoon next time, then keep doubling up to a normal serve for their age.
- One new allergen per meal. Introduce only one new common allergy food at the same meal, so it's clear which food caused any reaction.
- Keep it going. Once tolerated, offer each allergen at least once a week as part of a varied diet.
Stay with your baby while they eat, sitting upright, both to watch for a reaction and to reduce the risk of choking. The choking vs gagging guide covers safe preparation.
Don't rub food on the skin
ASCIA says never rub or smear food on your baby's skin to "test" it. It won't show whether your baby is allergic, and frequent skin contact with a food without eating it may make allergy more likely.
A note on eggs in the UK
The NHS says UK eggs with the British Lion stamp can be eaten raw or lightly cooked by babies. For first tastes as an allergen, ASCIA's advice is well-cooked egg, which is a sensible starting point wherever you live.
What does an allergic reaction look like?
If a reaction happens, it usually starts quickly. The ASCIA anaphylaxis FAQ separates mild to moderate signs from anaphylaxis, the most severe type of allergic reaction.
| Mild to moderate | Anaphylaxis (emergency) |
|---|---|
| Hives or welts | Difficult or noisy breathing |
| Swelling of lips, face or eyes | Swelling of the tongue |
| Vomiting | Swelling or tightness in the throat |
| Becoming very unsettled | Wheeze or persistent cough |
| Hoarse voice or collapse | |
| Pale and floppy |
ASCIA says a mild to moderate reaction may come before anaphylaxis, but anaphylaxis can also happen without milder signs first.
The NHS food allergy guide is stricter about the lips: it says to call an ambulance if the lips, mouth, throat or tongue suddenly become swollen. This guide follows the stricter advice, so sudden lip swelling after a food is in the emergency list below.
Redness only around the mouth
A mild rash only around the mouth — redness or hives that appear during or just after eating, with no other signs — is not usually an allergic reaction, according to ASCIA. Offer the food again when your baby is well. A fragrance-free barrier cream on the chin and offering food on a spoon can reduce skin contact.
What should I do if my baby has a reaction?
For anaphylaxis signs, follow the ASCIA first aid plan for anaphylaxis:
- Lay your baby flat, or hold a young child flat rather than upright. Don't let them stand or walk.
- Give an adrenaline (epinephrine) device if your baby has one prescribed. ASCIA says if in doubt, give it.
- Call your local emergency number (000 in Australia, 999 in the UK, 911 in the US) for an ambulance.
- Start CPR at any time if your baby is unresponsive and not breathing normally.
The NHS food allergy page adds that you should still call an ambulance after using an adrenaline device, even if your baby seems better. If your baby has a diagnosed allergy, follow their ASCIA Action Plan or the allergy plan your doctor gave you.
For mild to moderate signs, stop giving that food, stay with your baby and watch closely, and get medical advice. ASCIA advises getting specialist advice before offering that food again.
Keep going with other allergens. ASCIA says a reaction to one food is not a reason to stop introducing the others. A baby allergic to cow's milk should still have egg and peanut, for example. Babies with an allergy to cow's milk, wheat or several foods should also see an allergy dietitian.
Does eczema change how I introduce allergens?
Babies with eczema, another food allergy, or a parent or sibling with allergies have a higher chance of food allergy. ASCIA's advice is that they should still have common allergy foods in the first year, because delaying makes allergy more likely. Keeping eczema well controlled, together with early introduction, may help reduce the risk.
US and UK guidance adds a step for some babies:
- The AAP suggests talking with your paediatrician first if your baby has severe, persistent eczema or has had an immediate allergic reaction to a food. It calls these babies high risk for peanut allergy and says peanut foods should ideally be introduced as early as 4 to 6 months.
- An AAP report on early peanut introduction says babies with severe eczema needing prescription treatment, or an egg allergy, may start peanut as early as 4 to 6 months. Testing and introduction under a health professional's supervision may be considered.
- The NHS suggests talking to your GP or child-health nurse first if your baby has eczema or a diagnosed food allergy.
If your baby's eczema is hard to control, it is worth raising before you start solids so you have a plan that suits them.
What's worth writing down?
A short note for each new allergen helps: the food, how it was prepared, the amount, the time, and anything you noticed in the next two hours. If there's a reaction, a photo of the rash and the time it started are useful for the doctor. A list of allergens already tolerated also makes it easier to keep each one going weekly.
When should I get help?
Call your local emergency number (000 in Australia, 999 in the UK, 911 in the US) now if your baby has:
- difficult or noisy breathing, a wheeze or a persistent cough
- sudden swelling of the lips, tongue or throat
- a hoarse voice or cry, or collapses
- become pale and floppy
See a doctor today if your baby has:
- hives or welts beyond the mouth area, or swelling of the face or eyes, with normal breathing
- vomiting after a new food
Talk to your GP or child-health nurse if:
- your baby has eczema that's hard to control, or a known food allergy, before starting allergens
- you're unsure how to introduce a food after a past reaction
- your baby isn't eating solids yet by around 7 months, which ASCIA suggests discussing