Key takeaways: Introduce common allergens, such as peanut and egg, along with other solids around 6 months (and not before 4 months). Babies with severe eczema or egg allergy may need evaluation first. Keep allergens in the diet regularly once introduced.
Advice on food allergies has changed dramatically. Delaying allergens is no longer recommended. Early introduction can help prevent allergies.
Why Early Introduction?
The landmark LEAP trial, published in 2015, found that introducing peanut early to high-risk infants reduced peanut allergy by about 80 percent compared with avoiding it. Since then, guidelines have recommended early introduction of peanut, and more recently, other common allergens.
The 2025-2030 Dietary Guidelines for Americans, released in January 2026, recommend introducing a variety of potentially allergenic foods along with other complementary foods during infancy.
Common Allergens
- Peanut
- Tree nuts
- Egg
- Cow’s milk (as yogurt or cheese; not as a drink before 12 months)
- Wheat
- Soy
- Fish
- Shellfish
- Sesame
Who Needs a Doctor’s Guidance First?
According to NIAID’s 2017 peanut guidelines:
- Babies with severe eczema, egg allergy, or both: high risk. Talk to your doctor before introducing peanut. They may recommend allergy testing or a supervised first feeding, with peanut introduced as early as 4 to 6 months.
- Babies with mild to moderate eczema: introduce peanut around 6 months, at home in most cases.
- Babies without eczema or food allergy: introduce peanut along with other solids.
Talk to your doctor if your baby has had any allergic reaction to food.
How to Introduce Allergens Safely
- Start when your baby is healthy and already eating some solids.
- One new allergen at a time, waiting a few days before the next.
- At home, earlier in the day, so you can watch for reactions.
- Use safe forms:
- Peanut: smooth peanut butter thinned with water, breast milk, or formula, or peanut powder mixed into purees. Never whole peanuts or globs of peanut butter.
- Egg: well-cooked, scrambled, or hard-boiled and mashed.
- Dairy: plain yogurt or soft cheese.
- Wheat: infant cereals, soft pasta.
- Fish: flaked, boneless, well-cooked fish.
- Tree nuts and sesame: smooth nut butters or tahini, thinned.
- Keep them in the diet regularly, several times a week. Ongoing exposure appears important.
Signs of an Allergic Reaction
Mild: a few hives around the mouth, mild redness.
Severe (anaphylaxis):
- Widespread hives.
- Swelling of the face, lips, or tongue.
- Coughing, wheezing, or trouble breathing.
- Repeated vomiting.
- Pale, floppy, or unusually sleepy.
Call 911 immediately for trouble breathing, facial swelling, repeated vomiting, or if your baby becomes pale or limp. Stop the food and call your doctor for mild symptoms like a few hives.
The Bottom Line
Early, regular introduction of common allergens, starting around 6 months, can help prevent food allergies. Talk to your doctor first if your baby has severe eczema or a known allergy.
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Sources
- Du Toit G, Roberts G, Sayre PH, et al; LEAP Study Team. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015;372(9):803-813.
- Togias A, Cooper SF, Acebal ML, et al. Addendum guidelines for the prevention of peanut allergy in the United States: report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. J Allergy Clin Immunol. 2017;139(1):29-44.
- Fleischer DM, Chan ES, Venter C, et al. A consensus approach to the primary prevention of food allergy through nutrition. J Allergy Clin Immunol Pract. 2021;9(1):22-43.
- Greer FR, Sicherer SH, Burks AW; Committee on Nutrition; Section on Allergy and Immunology. The effects of early nutritional interventions on the development of atopic disease in infants and children. Pediatrics. 2019;143(4):e20190281.
- US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. Released January 2026. https://www.dietaryguidelines.gov
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
