The approach to preventing food allergies in infants has shifted dramatically in recent years. Medical guidance previously advised delaying the introduction of common allergenic foods, but current research now supports a proactive strategy of early introduction. This change is based on significant evidence suggesting that introducing allergens like peanut and egg early in an infant’s diet can reduce the risk of developing a food allergy later in life. This method aims to build tolerance through controlled, consistent exposure rather than avoidance. Parents can confidently begin this process, understanding that this preventative measure is supported by major pediatric and allergy organizations.
Establishing Readiness and Timing
The timing for introducing any solid food, including allergens, is determined by a baby’s developmental readiness, not just a specific date on the calendar. While the recommended window for starting solids is generally around six months of age, it should not be before four months. For most babies, the introduction of common allergens should begin once they are already regularly eating other, lower-risk solid foods.
Infants must meet specific developmental milestones to safely begin this process. These include being able to sit up with support and demonstrating good head and neck control, which reduces the risk of choking. Loss of the tongue-thrust reflex, which causes a baby to automatically push food out, is another indicator. The baby should also show interest in food, such as reaching for items or opening their mouth when presented with a spoon.
For infants at a higher risk of developing a food allergy, such as those with severe eczema or an existing egg allergy, early introduction is particularly important. These children may benefit most from introducing peanut products as early as four to six months of age. Parents of high-risk infants should consult with a pediatrician or allergist before beginning to establish the safest approach. Waiting beyond the first year to introduce common allergens, particularly peanut and egg, may increase the chance of an allergy developing.
Systematic Introduction of Priority Allergens
The preventative strategy requires the systematic and consistent introduction of common allergens. The nine major food allergens in the United States include:
- Milk
- Eggs
- Wheat
- Soy
- Tree nuts
- Peanuts
- Fish
- Shellfish
- Sesame
To safely identify any potential reactions, parents should introduce one new allergenic food at a time. After the first exposure, wait two to three days before introducing another new food.
The first exposure to an allergen should involve only a small amount, such as a quarter-teaspoon, mixed into a food the baby has already tolerated well, like a pureed fruit or vegetable. If no reaction occurs after the initial small taste, the amount can be gradually increased during the next feeding. Perform the first few exposures at home when the baby will be awake for at least two hours, allowing for close monitoring.
Peanut is a primary focus because early and consistent exposure reduces the risk of developing a peanut allergy. Whole peanuts or chunky peanut butter are choking hazards and must be avoided. Instead, thin a small amount of smooth peanut butter considerably with breast milk, formula, water, or a pureed food to create a safe, easily swallowed consistency. Another option is to use peanut powder or flour mixed into a baby cereal.
Egg is another common allergen that should be introduced early in a well-cooked form, as raw or runny egg is not safe. A small portion of a finely scrambled or hard-boiled egg can be mashed into a puree. Dairy can be introduced in the form of whole-milk yogurt or Greek yogurt, which can be mixed with a fruit puree. Whole cow’s milk is not recommended as a primary beverage until after one year of age.
To maintain the tolerance developed during the initial introduction, continued frequent exposure is essential. Once an allergen has been safely introduced, it should be offered regularly, ideally two to three times per week. This consistent feeding pattern helps the baby’s immune system recognize the food protein as a normal part of the diet, which prevents the development of a food allergy.
Recognizing and Managing Allergic Reactions
Parents must be prepared to recognize the signs of an allergic reaction, which typically occur within minutes to two hours after consumption. Symptoms can range from mild to severe and may involve the skin, digestive system, or respiratory system. Mild reactions may include a few isolated hives, a mild rash, an itchy mouth, a runny nose, or a single episode of vomiting. If only mild symptoms are present, stop the feeding and contact the child’s pediatrician for further guidance.
More severe reactions involve extensive symptoms or affect multiple body systems. Signs of a serious reaction, known as anaphylaxis, include swelling of the face, lips, or tongue, and widespread hives. Respiratory symptoms, such as wheezing, repetitive cough, difficulty breathing, or a hoarse voice, also indicate a severe reaction. If an infant exhibits any signs of a severe reaction, such as sudden lethargy, paleness, or difficulty breathing, call emergency services immediately.
Parents should discuss the potential need for age-appropriate antihistamines or an epinephrine auto-injector with their child’s physician. While a severe reaction is rare, having an emergency action plan and the appropriate medication available provides a safety net. Any suspected allergic reaction should be documented and discussed with a doctor before reintroducing the food.