Allergen introduction planner
Enter your baby's age and whether they have eczema or a known allergy, and this lays out an order for introducing the common allergen foods, one at a time. It follows NHS guidance, gives no quantities, and sends higher-risk babies to a clinician first.
Allergen introduction planner
No sign-up · PrivateUsed only to work out when they reach around 6 months, which is when the NHS says solid foods — and allergen foods with them — start.
The NHS says you may need to be particularly careful in these cases. If you pick either of them, this tool stops and sends you to your GP or health visitor instead of producing a plan.
Optional. Leave blank for “as soon as they are old enough”. If the date is before they reach around 6 months, the plan moves to that date.
The rule that matters is one at a time. The spacing is yours to choose; more space makes a reaction easier to attribute, less space gets more foods into the diet sooner.
Start allergen foods from
One food at a time, 3 days apart, finishing the list around 12 February 2027. No amounts — these go in as part of ordinary food.
Your baby reaches around 6 months on: 10 January 2027 — that is 154 days away.
Start date moved: You asked to start on 10 July 2026, which is before your baby reaches around 6 months. The plan starts on 10 January 2027 instead. Solid foods start at around 6 months; there is no separate later date for allergen foods, and no earlier one either.
One at a time, 3 days apart: The whole list takes 33 days, finishing around 12 February 2027. The one-at-a-time rule is about diagnosis, not danger: offer peanut, egg and sesame in the same afternoon and a rash tells you almost nothing, except that you now have three foods you are frightened of.
First three steps: 1. Cows’ milk from 10 January 2027. 2. Eggs from 13 January 2027. 3. Foods containing gluten from 16 January 2027.
The order is not prescribed: There is no required order and this is one workable sequence, not a recommendation about which food comes first. Peanut and egg attract the most attention because they are the most studied, but the principle is the same for all of them. Move things around to suit what you already cook.
Amounts: None are given here, and that is deliberate. No authority publishes allergen quantities for home introduction, so any number would be invented. These go in as part of ordinary family food.
Keep them in the diet: The part that gets forgotten. Once a food has been tolerated the goal is not to tick it off a list — it is to get it into the ordinary diet and keep it there. A food that went in fine and was then never offered again has not really been introduced.
Also on the NHS list: Beans, lentils and peas appear among the foods that can trigger reactions. They are not on the schedule above because they are usually already part of ordinary weaning food — apply the same one-at-a-time approach when they first appear.
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How this is calculated
FormulaHow this plan is built
This tool sequences foods. It does not prescribe amounts, and it does not tell you how much of anything to give, because no authority publishes allergen quantities for home introduction and inventing them would be exactly the wrong kind of precision.
Step 1 — the timing
The NHS position is that solid foods start at around 6 months, and that the foods which can trigger allergic reactions are introduced from around 6 months as part of the diet, just like any other food. There is no instruction to delay them. Delaying is what used to be advised, and the advice changed.
Step 2 — one at a time
The single mechanical rule that makes this work: introduce allergen foods one at a time, so that if there is a reaction you know what caused it. Introducing three new things in a day tells you nothing except that something happened.
The tool spaces introductions accordingly and keeps a running list of what has already been given, because once a food has been tolerated the point is to keep it in the diet rather than to tick it off and move on.
Step 3 — the foods on the list
The NHS names these as the foods that can trigger allergic reactions: cows' milk; eggs, where eggs without a red lion stamp should not be eaten raw or lightly cooked; foods containing gluten, including wheat, barley and rye; nuts and peanuts, served finely ground or as nut butters; seeds, particularly sesame, served finely ground; soya; shellfish, not served raw or lightly cooked; fish; celery; mustard; and sulphur dioxide, sometimes found in dried fruits and fruit juices.
Note that two entries carry a preparation rule that is about choking rather than allergy. Whole nuts and whole seeds are a choking hazard for young children, which is why the guidance says finely ground or as a butter. The tool repeats that alongside every nut and seed step.
Step 4 — the higher-risk route
The NHS says that if your baby already has a diagnosed food allergy or eczema, or there is a family history of food allergies, eczema, asthma or hay fever, you may need to be particularly careful when introducing these foods. Where you tell the tool that any of these applies, it stops giving you a plan and tells you to talk to your GP or health visitor first.
That is deliberate. Babies with significant eczema or an existing allergy are the group where introduction is sometimes done under supervision, and a website is not the right place to decide that.
Step 5 — what a reaction looks like
The tool shows the signs at every step rather than burying them: swollen lips or face; red, itchy, watery eyes; wheezing and coughing; a red, itchy rash; worsening eczema; feeling or being sick; tummy pain, diarrhoea or constipation; sneezing; a runny or blocked nose; worsening asthma. Most reactions are mild.
Severe reactions are a medical emergency. Difficulty breathing, swelling of the throat or tongue, or a baby who becomes floppy or unresponsive means calling 999 immediately.
When and how to introduce allergens to your baby
The advice on this changed, and it changed in the opposite direction to what most people expect. Parents were once told to hold back peanuts, eggs and other common triggers, sometimes for years. That is no longer the guidance. The current NHS position is that these foods are introduced from around six months as part of the diet, like any other food, and that they are not held back.
If you were given the older advice for an earlier child, or your family remembers it, this is the source of a lot of well-meant but out-of-date pressure. The change is genuine and it is reflected in current guidance.
Start at around six months
Solid foods start at around six months, and allergen foods can be part of that from the beginning. There is no separate later date for them. What matters is not the calendar but the method: one new allergen at a time, so that if something happens you know what it was.
In practice most families introduce a first few plain foods, then start working allergens in among them. There is no required order. Peanut and egg attract the most attention because they are the most studied, but the principle is the same for all of them.
One at a time, and then keep going
The one-at-a-time rule is about diagnosis, not danger. If you offer peanut, egg and sesame in the same afternoon and your baby comes out in a rash, you have learned almost nothing and now have three foods you are frightened of. Spacing them out means a reaction points somewhere specific.
The part that gets forgotten is what happens after a food is tolerated. The goal is not to tick foods off a list; it is to get them into the ordinary diet and keep them there. A food that went in fine at seven months and was then never offered again has not really been introduced.
The foods that come up most
The NHS list covers cows' milk, eggs, gluten-containing foods including wheat, barley and rye, nuts and peanuts, seeds including sesame, soya, shellfish, fish, celery, mustard, and sulphur dioxide, which turns up in some dried fruit and fruit juice. Beans, lentils and peas also appear on the list of foods that can trigger reactions.
Two preparation rules run alongside the allergy advice and are about choking instead. Whole nuts and whole seeds should not be given to young children; grind them finely or use a smooth butter, thinly spread or mixed into other food. And eggs without a red lion stamp should not be served raw or lightly cooked. Shellfish should not be served raw or lightly cooked either.
Cows' milk is a special case
Cows' milk as a food — in cooking, in yoghurt, in cheese — can be introduced from around six months. Cows' milk as a main drink is different, and is not recommended before twelve months. Those are two separate questions that often get merged, and merging them causes unnecessary confusion.
If your baby has eczema or an allergy already
This is the part to take seriously. The NHS says that if your baby already has a diagnosed food allergy or eczema, or if there is a family history of food allergies, eczema, asthma or hay fever, you may need to be particularly careful when introducing these foods.
Babies with significant eczema, especially eczema that started early and is hard to control, are at higher risk of food allergy, and introduction is sometimes planned with clinical input rather than improvised at home. If that describes your baby, speak to your GP or health visitor before starting, and say clearly what the eczema has been like. This is not a reason to delay indefinitely — delay is not protective — it is a reason to get advice about how to go about it.
What a reaction looks like
Most reactions in babies are mild. Swollen lips or face, red itchy watery eyes, a red itchy rash, worsening eczema, sneezing, a runny or blocked nose, being sick, tummy pain, diarrhoea or constipation, wheezing and coughing are the things to watch for. They usually come on quickly after the food.
A severe reaction is different and is an emergency. Difficulty breathing, swelling of the throat or tongue, or a baby who goes floppy or unresponsive needs an ambulance. Call 999. Do not drive to hospital and do not wait to see whether it settles.
If your baby has a mild reaction, stop that food, and speak to your GP before offering it again. Do not run your own retrial at home on a food that has caused a reaction, and be wary of allergy testing sold direct to consumers, which frequently produces results that mean nothing and leads to unnecessary exclusions.
What not to do
Do not cut foods out of your own diet in pregnancy or while breastfeeding to prevent allergy. The NHS is explicit that you do not need to avoid foods that can trigger allergic reactions, including peanuts, unless you are allergic to them yourself. And do not remove foods from your baby's diet on suspicion without advice, because unnecessary exclusion carries its own nutritional cost and can make matters worse.
If you are unsure at any point, your health visitor is the right first call. This planner sequences foods; it does not diagnose anything, and it is not a substitute for advice about your particular baby.
Sources
- Food allergies in babies and young children — NHS, accessed
- Your baby's first solid foods — NHS, accessed
- Weaning — NHS Start for Life, accessed
- Food allergy and intolerance — Food Standards Agency, accessed
- British Society for Allergy and Clinical Immunology — BSACI, accessed