Early allergen introduction, done safely

Delaying allergens doesn't prevent allergy — introducing them early, around 6 months, and keeping them in the diet does. Here's how to introduce the top nine safely and make it stick.

Why early introduction

For years parents were told to avoid allergens in infancy. The evidence flipped that. The landmark LEAP trial found that introducing peanut early cut peanut allergy dramatically in high-risk infants, and the EAT study supported early introduction of multiple allergens. Today the AAP and NIAID recommend introducing the common allergens around 6 months, alongside other first foods — not delaying them.

The top 9 allergens

In the U.S., nine foods account for most food allergies. Introduce each in a baby-safe form:

• Peanut — smooth peanut butter thinned with water/breast milk, or peanut puffs. Never whole/chopped peanuts or a thick glob.
• Egg — well-cooked (scrambled or hard-boiled and mashed).
• Milk (dairy) — full-fat yogurt or cheese (not cow's milk as a drink before 12 months).
• Tree nut — smooth nut butters (almond, cashew) thinned out.
• Soy — soft tofu, mashed edamame.
• Wheat — iron-fortified wheat cereal, soft pasta, toast strips.
• Fish — well-cooked, flaked low-mercury fish (salmon, cod), bones removed.
• Shellfish — well-cooked, finely chopped (e.g. shrimp).
• Sesame — tahini thinned out, or smooth hummus.

How to introduce one safely

1. Introduce one new allergen at a time.
2. Offer it at home, not at daycare or a restaurant.
3. Offer it earlier in the day so you can watch afterward.
4. Start with a small taste, then a fuller serving if there's no reaction.
5. Watch for about 2 hours for any reaction.
6. If tolerated, keep offering it regularly to maintain tolerance.

Watch for a reaction

Mild: a few hives or redness around the mouth, mild lip swelling, some fussiness. Severe (call your emergency number now): widespread hives, swelling of the face/lips/tongue, vomiting or diarrhea, coughing/wheezing/trouble breathing, or a pale, floppy, unusually drowsy baby — this may be anaphylaxis.

Keep it going — this is the part people miss

Introducing an allergen once isn't enough. Once your baby tolerates it, keep offering it regularly — about twice a week (roughly 2 g of protein, e.g. ~1½ teaspoons of peanut butter or one small egg). Stopping for long stretches can let an allergy re-develop, so ongoing, regular exposure matters as much as the first taste.

How First Bites helps

This "introduce, watch, then keep going" pattern is exactly what First Bites tracks. Each allergen gets a rolling window — watching while you build tolerance (with the 2-hour acute-watch reminder), established once it's tolerated, and a nudge when one is lapsing below ~2×/week. Open the free app →