MamaBeeHow to Introduce Allergens to Your Baby (Without the Guesswork)
If your own parents raised you, they were probably told to keep peanuts away from babies until age three. That advice was wrong. Not slightly out of date — actually backwards. Delaying the major allergens appears to have made childhood food allergy more common, not less.
The evidence that flipped it came from a landmark trial that gave peanut to high-risk infants early and found a dramatic reduction in peanut allergy by age five compared with avoiding it. Guidance across the US changed to match. Early, regular introduction is now what is recommended.
So if you are standing in your kitchen holding a jar of peanut butter feeling slightly terrified, that is a normal place to be. Here is how to do it methodically.
When to start
Start allergens once your baby is eating solids, generally around six months — and not before four months. Your baby should already be handling a few simple first foods and showing the usual readiness signs: sitting with good head control, interested in food, no longer pushing everything back out with their tongue.
There is one important exception. If your baby has severe eczema, an existing egg allergy, or both, talk to your pediatrician first. Those babies are the highest-risk group, and guidance for them is to introduce peanut earlier — commonly around four to six months — sometimes after allergy testing. That is a conversation with your doctor, not a decision to make from an article.
Once a food is in and tolerated, keep it in. Regular exposure, roughly a couple of times a week, is what maintains tolerance. Introducing peanut once in July and never again does not count.
The nine major allergens
In the US, nine foods account for the large majority of food allergies: milk, egg, peanut, tree nuts, soy, wheat, sesame, fish and shellfish. Sesame was added as the ninth major allergen in 2023, so older baby books will not mention it.
| Allergen | Safe first form | Notes |
|---|---|---|
| Peanut | Smooth peanut butter thinned with water or milk, or peanut puffs | The most studied; earliest priority |
| Egg | Well-cooked scrambled or hard-boiled, mashed | Always fully cooked, never runny |
| Cow milk | Yoghurt or cheese | Dairy foods yes; milk as a drink waits until 12 months |
| Tree nuts | Smooth almond or cashew butter, thinned | Introduce individually, not as a blend |
| Sesame | Tahini thinned, or hummus | A major US allergen since 2023 |
| Wheat | Iron-fortified wheat cereal, soft pasta | Easy to fold into existing meals |
| Soy | Tofu, or plain soy yoghurt | Soft tofu mashes well |
| Fish | Well-cooked flaked salmon or cod | Check carefully for bones |
| Shellfish | Well-cooked, finely chopped | Often introduced a little later |
The method that keeps it manageable
The point of a system is that if something happens, you know exactly which food caused it.
- One new allergen at a time. Never debut two on the same day.
- Morning or early afternoon, at home, when you can watch your baby for a couple of hours and your doctor's office is open. Not at 6 PM the night before travel.
- Start tiny. A quarter-teaspoon on the tip of a spoon. Wait ten minutes. If nothing happens, offer a bit more.
- Wait a few days before adding the next new allergen, so a delayed reaction is still attributable.
- Keep it plain. No new spices, no new textures, nothing else new that day.
- Write it down. Which food, how much, what time, and anything you noticed. Four allergens in, memory will not be reliable.
That last one is where a tracker earns its place — the MamaBee Solid Food Allergen Test walks you through the introductions one at a time and keeps the record, so when your pediatrician asks "when did you introduce egg and what happened," you have an actual answer instead of a guess.
Introduce allergens one at a time with MamaBee's Solid Food Allergen Test — and keep a record your pediatrician can actually use.
Get the appWhat a reaction looks like
Most reactions are mild, appear within minutes to about two hours, and never escalate. But you should be able to tell the two categories apart before you start, not while it is happening.
| Mild — call your doctor | Severe — call 911 immediately |
|---|---|
| A few hives around the mouth | Trouble breathing, wheezing, noisy breathing |
| Mild redness where food touched skin | Swelling of the lips, tongue or throat |
| One episode of vomiting | Repeated vomiting with pallor or floppiness |
| Loose stool later that day | Widespread hives plus any other symptom |
| Mild fussiness after a new food | Going pale, limp, blue, or unresponsive |
If you see anything in the right-hand column, call 911. Do not drive to the emergency room, do not phone the pediatrician first, and do not wait to see if it settles. Anaphylaxis in babies can look like sudden pallor and floppiness rather than the dramatic throat-closing you might picture.
For a mild reaction, stop the food, call your pediatrician, and ask before offering it again. Do not give antihistamines to a baby without being told to by a doctor.
Choking safety, which is a separate risk
Allergy and choking are different dangers, and the foods overlap. Regardless of allergies:
- Never give whole nuts to a child under four.
- Never give a spoonful of thick nut butter. It sticks to the roof of the mouth. Thin it with water, milk or yoghurt until it is easily swallowed, or spread it very thinly.
- Skip whole grapes, popcorn, raw hard vegetables, hard candy and round chunks of hot dog.
- Baby seated upright in a high chair, always supervised, never eating in a car seat or while crawling around.
- No honey before 12 months, allergy aside — the risk there is infant botulism.
What about family history?
A family history of food allergy raises the odds somewhat, but it does not change the basic advice: early introduction is still recommended, and avoidance is not protective. Mention the history to your pediatrician and follow their lead. Notably, avoiding allergens during pregnancy or breastfeeding has not been shown to prevent allergy in the baby.
For the bigger picture on first foods, see when to start solids.
Frequently asked questions
What age should I introduce peanut to my baby?
For most babies, around six months, once solids are established. For babies with severe eczema or egg allergy, guidance is to introduce earlier — often four to six months — after talking to your pediatrician.
How long should I wait between new allergens?
A few days is the usual advice. That gap makes a delayed reaction traceable to one specific food.
Does my baby need allergy testing before I start?
Most babies do not. Testing is generally reserved for high-risk infants — severe eczema, existing egg allergy — and is arranged by your doctor. Routine pre-testing is not recommended and can produce misleading results.
Can I introduce allergens if my baby has eczema?
Yes, and it matters more for those babies, not less. If the eczema is severe, speak with your pediatrician first about timing and whether testing is warranted.
What if my baby refuses the food?
Refusal is not a reaction. Offer it again another day in a different form — babies often need many exposures before accepting something new.
Do I need to keep giving it after the first taste?
Yes. Regular ongoing exposure, a couple of times a week, is what maintains tolerance. Introduce and then abandon is not the same as introducing.
The takeaway
Start around six months, one allergen at a time, in the morning at home, in tiny amounts, thinned and never whole. Know the difference between a few hives and trouble breathing before you begin. Keep the foods your baby tolerates in regular rotation, and write down what you did.
And if your baby has severe eczema, make the pediatrician call this week rather than next — for that group, timing genuinely matters.
Get MamaBee free — and let the Solid Food Allergen Test keep the record for you.
Get the app*This article is general information, not medical advice. Talk to your pediatrician before introducing allergens, especially if your baby has severe eczema, an existing food allergy, or a strong family history. If you see any sign of a severe reaction, call 911 immediately.*
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