Allergies can feel especially frightening when you have a newborn at home. Many parents worry that their child might have an unknown allergy or could develop one as they grow — often leading some parents to introduce common allergens like peanut butter to their babies in hospital parking lots.
Research shows that some allergies in newborns may be prevented through early, monitored and consistent exposure, helping parents feel greater peace of mind as their child develops and is regularly introduced to more complex foods.
Understanding Your Baby’s Allergy Risk
For parents concerned about allergies in their newborns and interested in preventive measures, a vital discussion is whether their child is at a higher risk of developing an allergy.
Elizabeth LeFave, DNP, APRN, a board-certified advanced practice nurse at Gainesville’s Allergy, Asthma and Immunology Consultants, with expertise in pediatric immunology and allergy, said that certain factors, such as severe eczema in infancy, can increase the risk of developing food allergies.
“A family history of allergic conditions — such as asthma, eczema, seasonal allergies or food allergies — can also increase the likelihood that a child may develop allergic disease, although it does not necessarily predict a specific food allergy,” she said.
Research shows that infants with eczema are five times more likely to have food allergies, and those with severe eczema are more likely to develop food allergies in their first year of life, according to Swedish Health Services.
According to the Mayo Clinic, allergies are caused when the immune system creates antibodies, which are protective proteins intended to attack invaders like germs, that then label a certain allergen as “harmful,” even though it is not. When the immune system is confronted with this substance, it will react with inflammation, leading to inflamed skin, airways, the digestive system or sinuses.
This is why skin issues have been linked to allergies in children, mainly because a damaged skin barrier, as seen in conditions like eczema, can allow allergens to enter the immune system more easily, according to Swedish Health.
Most Common Food Allergies
According to Johns Hopkins Medicine, about 90% of food allergies are caused by these allergens:
• Eggs
• Milk According to Food Allergy Research & Education, about 3% of infants develop a food allergy within their first year of life, and about 53% of these babies are allergic to the protein in cow’s milk.
• Peanuts
• Soybeans
• Sesame
• Shellfish
• Tree nuts
• Fish
• Wheat
Research has also shown that a vitamin D deficiency in infants can lead them to be three times more likely to develop an egg allergy and 11 times more likely to develop a peanut allergy. This is because vitamin D directly affects immune function, according to an article from Swedish Health.
Genetics can also create a higher risk of a child developing allergies, with one study showing that children who had one parent with an allergy were 30% to 50% more likely to develop one as well. Having both parents with allergies increases the risk by 60% to 80%, as stated in a study published by Paediatrics and Child Health.
Allergy Risks
According to the National Institute of Allergy and Infectious Diseases:
• Skin conditions such as eczema and dry skin
• Delayed introduction to allergens like eggs and peanuts
• Parental genetics and allergies
• Vitamin D deficiencies
• Diagnosed with asthma
How Can Early Exposure Help Prevent Allergies?
Food allergies typically appear in children around the age of 1, with about 8% of children under 5 having food allergies, according to articles from University Hospitals and John Hopkins Medicine. Outdoor seasonal allergies to substances such as pollen are typically triggered after age 3, often at ages 5 to 6.
However, allergies can appear at any age, from early in life to adulthood, even in individuals aged 60 to 70.
LeFave said that experts’ understandings of food allergy prevention has changed significantly over the past decade, and it is now clear that introducing allergenic foods during infancy can reduce the risk of certain food allergies.
Research also shows that delayed exposure can contribute to the development of allergic diseases, according to an article from the National Library of Medicine National Center for Biotechnology Information.
A 2025 study from the Children’s Hospital of Pennsylvania that analyzed health records from over 120,000 children found that early exposure to allergens was associated with a 36% decrease in new food allergy cases.
However, according to LeFave, early introduction of allergenic foods does not guarantee avoidance of allergies, but it can support healthy immune development and significantly reduce the risk of allergies, especially peanut allergies in higher-risk infants.
“The goal is to reduce risk and introduce foods safely, not to create pressure for parents,” she said. “Most families can approach this process gradually and confidently with guidance from their child’s healthcare provider.”
LeFave said that early introduction is typically safe for most infants, but in certain situations, additional guidance from a clinician may be helpful.
“Infants with severe eczema, those who have already had a reaction to a food or those with a known food allergy should discuss introduction of new allergenic foods with their healthcare provider,” she said.
How to Practice Early Exposure to Allergens
When introducing allergenic foods to your child, LeFave said that for most infants, these foods can be introduced once complementary foods begin, usually around 6 months of age, but not before 4 months.
To ensure your baby is ready for this introduction, make sure they can consume solid foods and sit up well without support. As you plan how to introduce the foods, be certain to do so at a time when they will be awake for 2 hours after eating so that they can be monitored, according to Food Allergy Canada.
The non-profit food organization also recommends not offering whole nuts or large pieces of food to prevent the risk of choking. LeFave advises starting with small amounts of an age-appropriate form of food, such as peanut powder mixed into puree, thinned smooth peanut butter or fully cooked eggs, and avoiding thick spoonfuls of nut butter as it is a choking hazard.
This process should be taken slowly, introducing one food at a time and in slow amounts, either in one sitting over two to three days. This can be done by putting a small amount of the food, such as peanut butter, on the tip of a spoon, tasting it and waiting for any signs of allergic symptoms within the next few minutes, and then continuing to slowly feed it to your child, according to Food Allergy Canada.
If the process is successful and there are no food allergy symptoms, continue feeding the potential allergen to your child about once a week.
“Once a food is tolerated, offering it regularly as part of the diet may help maintain tolerance,” LeFave said.
For higher-risk infants, specifically those with moderate to severe eczema or a peanut allergy, LeFave said that foods with peanuts might be introduced earlier, usually around 4 to 6 months old, as advised and possibly supervised by the child’s doctor.
Though early introduction of allergenic foods can lower the risk, it does not guarantee allergy prevention. LeFave said to speak with your child’s clinician to further understand introduction methods, your child’s risk factors, feeding plans and if they should be monitored in a supervised medical setting or receive allergy testing.
“Coaching parents usually involves discussing when their baby is developmentally ready for solid foods, explaining safe ways to introduce common allergens such as peanut and egg and helping families feel confident recognizing and responding to possible reactions,” she said.
How to Know if Your Baby Is Having an Allergic Reaction
According to LeFave and an article from Solid Starts:
• Symptoms will often be visible within 2 hours after contact with or consumption of the allergen, but they usually appear within several minutes
• Itchy or runny nose
• Sneezing
• Itchy mouth
• A few hives and itchiness, hives in an isolated area
• One episode of vomiting
• Digestive discomfort or nausea
• Blotches around the mouth
Severe Symptoms:
Call 911 Immediately.
• Facial rash
• Swelling of the face, lips or tongue
• Pale, ashy or bluish skin
• Wheezing, difficulty breathing or a cough that will not stop
• Vomiting or diarrhea that will not stop
• Hives covering the body
• Sudden lethargy and weakness
Always consult with your pediatrician before introducing any new foods to your baby.
