How to Introduce Allergens to Your Baby (and Track It)
Your pediatrician said to start introducing allergens. They did not say how to keep track of which ones, when, or what happened afterward. That part is on you.
If your baby is approaching the 4 to 6 month mark and you need a baby allergen introduction schedule that actually makes sense, you are in good company. The science on early allergen introduction is clear. The logistics of tracking nine foods across weeks of wait windows are a mess.
The science has flipped
For decades, parents were told to delay allergenic foods until age one or later. That advice is now outdated. The landmark LEAP trial demonstrated that early, sustained peanut consumption in high-risk infants (starting between 4 and 11 months) reduced peanut allergy by 81% compared to avoidance (Du Toit et al., NEJM, 2015). The EAT trial extended this finding to the general population, showing that early introduction of six allergenic foods from 3 months of age was safe and, when families adhered to the protocol, significantly reduced allergy to both peanut and egg (Perkin et al., NEJM, 2016).
The current consensus from the AAP and ASCIA is straightforward: introduce common allergens early, around 4 to 6 months, alongside other solid foods. Delaying does not protect your baby. Early exposure may.
If your baby has severe eczema or an existing food allergy, talk to your pediatrician before starting. For most babies, though, you can begin at home.
The top 9 allergens and how to serve them
Under the Food Allergen Labeling and Consumer Protection Act (FALCPA), nine foods account for the vast majority of serious allergic reactions. Here is each one with a baby-safe first serving:
| Allergen | First food form | Typical introduction age |
|---|---|---|
| Peanut | Thinned peanut butter mixed into puree or cereal. Never whole peanuts. | 4-6 months |
| Egg | Well-cooked scrambled egg or hard-boiled yolk mashed into puree | 4-6 months |
| Cow’s milk | Plain whole-milk yogurt or cheese. Not cow’s milk as a drink until 12 months. | 4-6 months |
| Wheat | Infant cereal, soft cooked pasta, or thin toast strips | 4-6 months |
| Soy | Silken tofu mashed, edamame pureed, or soy yogurt | 4-6 months |
| Tree nuts | Thinned almond or cashew butter mixed into puree. Never whole nuts. | 6+ months |
| Fish | Flaked, well-cooked mild fish like salmon or cod | 6+ months |
| Shellfish | Well-cooked shrimp or crab, finely minced or pureed | 6+ months |
| Sesame | Tahini mixed into puree, hummus | 4-6 months |
Start with a small amount: about a quarter teaspoon for nut and seed butters, or a few bites for solid foods. Offer it in the morning or early afternoon so you have hours to observe before bedtime.
The wait-window rule
Introduce one new allergen, then wait 3 to 5 days before introducing the next. During that window, watch for reactions. If something happens, you know what caused it.
This sounds manageable until you do the math. Nine allergens at 3 days apart means a minimum of 27 days. At 5 days, it is 45 days. And that is just the introductions. After each allergen is cleared, guidelines recommend offering it again at least once a week to maintain exposure. By allergen number six, you are managing introductions for new foods and maintenance for cleared ones simultaneously.
This is the core tracking problem. It is not that any single day is hard. It is that the cumulative record stretches across weeks, involves overlapping schedules, and depends on you remembering things that happened on Tuesday when it is now Saturday.
What to track for each introduction
For every new allergen, record four things:
- Which allergen and what food form (peanut butter in oatmeal, scrambled egg, yogurt)
- Date and time of the first serving
- Reaction observed: none, mild, moderate, severe, or unsure
- Notes on anything unusual in the following days
“Unsure” is a valid and important option. Your baby might develop a mild rash that could be the new food, the new laundry detergent, or teething drool irritation. Recording “unsure” means you will reintroduce that allergen more carefully next time, rather than either panicking or ignoring it.
Mild reactions include a few hives around the mouth, slight redness, or minor fussiness. These often resolve on their own within an hour. Mention them to your pediatrician at the next visit.
Moderate reactions include widespread hives, persistent vomiting, significant swelling, or a rash that spreads beyond the contact area. Call your pediatrician the same day.
Severe reactions include difficulty breathing, swelling of the tongue or throat, sudden lethargy, or multiple symptoms involving two or more body systems (skin + vomiting, for example). Call 911.
Tracking allergens: paper, apps, and dedicated tools
Allergen tracking is different from logging daily feeds and diapers. It happens over weeks, involves conditional logic (wait 3 days, then proceed, but only if no reaction), and requires a different kind of record than a simple tally.
Paper charts work well for the first two or three allergens. A fridge chart with columns for allergen, date started, wait window, reaction, and cleared date is simple and visible. By allergen six, though, you are cross-referencing introduction dates with maintenance schedules, and the chart starts looking like a wall of sticky notes.
Baby tracking apps vary widely here. Most do not have a dedicated allergen feature, so parents hack it with notes fields or food logs. That works if you are disciplined, but the data is buried in a stream of feeds and diapers rather than visible as a structured checklist.
Nubo’s guided allergen introduction was built for exactly this workflow. It walks you through all 9 FALCPA allergens with a structured checklist, a wait-window countdown that tells you when it is safe to try the next food, reaction logging with severity levels, and auto-reminders when the wait period clears. Because it syncs across caregivers, the nanny or grandparent knows exactly which allergens have been introduced and which are still pending. No group text needed.
The pediatrician payoff
At your baby’s 6-month or 9-month visit, the pediatrician will ask about solid food introduction and allergen exposure. Having a structured allergen history (which of the 9 allergens, dates introduced, any reactions with severity) is far more useful than “I think we did peanut butter a few weeks ago.”
If your baby does have a reaction and gets referred to an allergist, the first thing they will want is a timeline: when the food was introduced, what form, how much, and what happened. Accurate records turn a 20-minute intake interview into a 5-minute one and help the allergist make better decisions. For more on preparing data for medical visits, see the pediatrician visit preparation guide.
What if my baby reacts?
Most babies tolerate all nine allergens without any issue. The LEAP trial found that even among high-risk infants (those with severe eczema or existing egg allergy), 89% tolerated peanut from the first introduction. For general-population babies, reactions are uncommon.
When they do happen, mild contact reactions around the mouth are the most frequent. These usually resolve within 30 to 60 minutes and do not necessarily mean your baby has a food allergy. Your pediatrician can help determine whether a re-challenge is appropriate or whether allergy testing is warranted.
The goal is not to avoid reactions entirely. It is to introduce allergens in a controlled way, have a clear record of what happened, and respond appropriately. A structured tracker turns the 4-to-6-week allergen introduction window from a mental juggling act into a checklist you can actually follow.
This post is for informational purposes. Consult your pediatrician before introducing allergens, especially if your baby has eczema or a family history of food allergies.
Frequently asked questions
What are the top 9 baby allergens?
The nine major allergens recognized under FALCPA are: milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans, and sesame. Together, these account for the vast majority of food allergy reactions in children. Most can be introduced between 4 and 6 months of age in age-appropriate forms.
How long should I wait between introducing new allergens?
Wait 3 to 5 days between each new allergen. This window lets you observe for delayed reactions and identify the cause if one occurs. Continue offering previously cleared allergens at least once a week during this period to maintain exposure.
What counts as a mild allergic reaction in a baby?
A mild reaction typically involves a few hives around the mouth or chin, slight skin redness at the contact area, or minor fussiness after eating. These symptoms usually resolve within 30 to 60 minutes without treatment. Report them to your pediatrician, but they do not necessarily indicate a true food allergy. Any breathing difficulty, widespread hives, vomiting, or swelling beyond the mouth area warrants immediate medical attention.