Allergen Tracker

Track your baby's progress through the top 9 allergens

Last reviewed:

Content reviewed against published AAP, ACAAI guidelines

Editorial policy

Key takeaways

  • Early allergen introduction (from 4-6 months) is now recommended by the AAP and can significantly reduce the risk of developing food allergies.
  • The top 9 allergens are milk, egg, peanut, tree nuts, wheat, soy, fish, shellfish, and sesame -- introduce them one at a time.
  • Watch for signs of an allergic reaction: hives, swelling of lips or tongue, vomiting, difficulty breathing, or widespread rash within minutes to hours after eating.
  • Babies with severe eczema or existing food allergies are at higher risk and may benefit from early evaluation by an allergist before introduction.
Current guidelines recommend early introduction of allergens (from 4-6 months) to reduce allergy risk. Tap a status badge to cycle through: Not Started → Introducing → Passed → Reaction.

Top 9 Allergens

0/9 cleared
Cow's Milk

Can introduce dairy products (yogurt, cheese) from 6 months. Whole milk as a drink from 12 months.

Introduction protocol

  • Start with a small amount of plain whole-milk yogurt
  • Wait 3-5 days before introducing another new food
  • Watch for reactions for at least 2 hours after first exposure
  • Gradually increase amount over several days

Watch for

  • Hives or skin rash
  • Vomiting or diarrhea
  • Bloody stool
  • Fussiness or excessive gas
  • Eczema flare-up

Common foods: Yogurt, Cheese, Butter, Cream, Ice cream

Egg

Introduce well-cooked egg from 6 months. Early introduction may reduce allergy risk.

Introduction protocol

  • Start with a small amount of well-cooked egg (scrambled is easiest)
  • Offer both white and yolk - the protein that causes reactions is in the white
  • Wait 3-5 days before introducing another new food
  • Continue offering 2-3 times per week to maintain tolerance

Watch for

  • Hives around mouth or body
  • Vomiting
  • Swelling of face or lips
  • Worsening eczema

Common foods: Scrambled egg, Hard-boiled egg, Egg in baked goods

Peanut

AAP recommends introducing peanut as early as 4-6 months, especially for high-risk babies (those with severe eczema or egg allergy).

Introduction protocol

  • NEVER give whole peanuts or chunky peanut butter - choking risk
  • Mix smooth peanut butter with warm water or breast milk to thin it
  • Or use peanut puffs (like Bamba) softened in milk
  • Start with a tiny amount on the tip of a spoon
  • Wait 10 minutes, then give a bit more if no reaction
  • For high-risk babies, discuss with your pediatrician first

Watch for

  • Hives
  • Swelling of face, lips, or tongue
  • Vomiting
  • Coughing, wheezing, or difficulty breathing - call 911

Common foods: Thinned peanut butter, Peanut puffs, Bamba snacks

Tree Nuts

Introduce tree nut butters (thinned) from 6 months. Never give whole nuts - choking hazard until age 4+.

Introduction protocol

  • Use smooth nut butters thinned with water or milk
  • Introduce one tree nut at a time
  • Wait 3-5 days between new tree nuts
  • Continue offering regularly to maintain tolerance

Watch for

  • Hives or rash
  • Swelling
  • Vomiting
  • Difficulty breathing - call 911

Common foods: Almond butter, Cashew butter, Walnut

Wheat

Introduce wheat-containing foods from 6 months.

Introduction protocol

  • Start with infant cereal or soft bread strips
  • Wait 3-5 days before introducing another allergen
  • Watch for digestive symptoms

Watch for

  • Hives or rash
  • Vomiting or diarrhea
  • Bloating or excessive gas
  • Eczema flare-up

Common foods: Bread, Pasta, Cereal, Crackers

Soy

Introduce soy foods from 6 months.

Introduction protocol

  • Start with soft tofu - mash it or cut into small pieces
  • Edamame should be mashed or cut (choking risk when whole)
  • Wait 3-5 days before next new food

Watch for

  • Hives
  • Vomiting or diarrhea
  • Fussiness
  • Eczema flare-up

Common foods: Tofu, Edamame, Soy yogurt

Fish

Introduce well-cooked, deboned fish from 6 months. Great source of omega-3.

Introduction protocol

  • Start with mild white fish (cod, tilapia) - flake it finely
  • Ensure all bones are removed
  • Cook thoroughly - no sushi or raw fish for babies
  • Wait 3-5 days before next new allergen

Watch for

  • Hives or skin rash
  • Vomiting
  • Swelling of face or lips
  • Difficulty breathing - call 911

Common foods: Salmon, Cod, Tilapia

Shellfish

Can introduce well-cooked shellfish from 6 months. Finely chop or puree.

Introduction protocol

  • Cook thoroughly and chop finely or puree
  • Start with a very small amount
  • Watch closely for reactions - shellfish allergy can be severe
  • Wait 3-5 days before next new allergen

Watch for

  • Hives
  • Swelling of face, lips, or throat
  • Vomiting
  • Difficulty breathing - call 911

Common foods: Shrimp, Crab, Lobster

Sesame

Introduce sesame from 6 months. Sesame was added as a major allergen in 2023.

Introduction protocol

  • Start with a thin layer of tahini mixed into puree or on toast
  • Or offer hummus (contains tahini)
  • Wait 3-5 days before next new allergen
  • Continue offering regularly

Watch for

  • Hives or rash
  • Vomiting
  • Swelling
  • Difficulty breathing - call 911

Common foods: Tahini, Sesame seeds (ground), Hummus

Frequently asked questions

When should I start introducing allergens to my baby?
Current guidelines recommend introducing common allergens between 4 and 6 months of age, once your baby has started solids. The landmark LEAP study showed that early peanut introduction reduced peanut allergy risk by up to 80 percent in high-risk infants.
How can I prevent peanut allergy in my baby?
For most babies, introduce peanut-containing foods (like thinned peanut butter mixed into puree) around 6 months. For high-risk babies with severe eczema or egg allergy, the AAP recommends introducing peanut as early as 4 to 6 months, possibly after allergy testing. Never give whole peanuts -- they are a choking hazard.
What does an allergic reaction look like in a baby?
Mild reactions may include a few hives around the mouth, mild rash, or slight fussiness. More serious reactions include widespread hives, swelling of face, lips, or tongue, vomiting, difficulty breathing, or becoming limp or unresponsive. Seek emergency care immediately for any severe symptoms.
Should I wait between introducing each allergen?
Yes. Introduce one new allergenic food at a time and wait 2 to 3 days before introducing another. This makes it easier to identify which food caused a reaction if one occurs. Once tolerated, continue offering the food regularly to maintain tolerance.

Bottom line

Early and consistent allergen introduction is one of the most effective strategies for reducing food allergy risk. Introduce the top 9 allergens one at a time starting between 4 and 6 months, monitor for reactions, and keep offering tolerated allergens regularly. If your baby has severe eczema or a family history of allergies, talk to your pediatrician or allergist before starting.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members

Based on AAP and LEAP study guidelines. Discuss allergen introduction timing with your pediatrician, especially if your baby has severe eczema or a family history of food allergies. All data stays on your device.