Help Your Newborn Stay Ahead of Food Allergies!

How To Prevent Food Allergies in Babies

Get a personalized approach to food allergy prevention for your children in St. Louis, Missouri. Dr. Sonia Cajigal is a board-certified allergist and immunologist that specializes in food allergies in babies and young children. Dr. Cajigal has helped countless patients navigate food allergy concerns and prevent the development of serious food allergies. Schedule your visit with St. Louis Family Allergy today!
“This office was AMAZING! I am so very impressed. I have never had more of a thorough doctor. The office staff was great too. I brought a newborn in and they all treated the situation of me having my baby there great. She made sure to lay everything out on the table of what could be the cause of my symptoms. She was so helpful. ” – Rachel M, March 2022
Pediatric Food Allergy Doctor Sonia Cajigal of St. Louis Family Allergy in St. Louis, Missouri
Food Allergy Prevention Specialist Dr. Sonia Cajigal of St. Louis Family Allergy review badges and affiliations

About Food Allergies in Babies

During Pregnancy
During Infancy

Food Allergy Testing

Food Allergy Treatment

How To Prevent Food Allergies in Babies During Pregnancy

Many mothers are surprised to learn that allergy prevention starts during pregnancy. Perhaps contrary to common belief, it is NOT recommended to avoid allergenic foods during your pregnancy. The one exception to this rule is if you have food allergies yourself, in which case, foods that you’re allergic to should be avoided. Recent evidence suggests that there is no significant allergy prevention benefit to your child if you avoid allergenic foods while pregnant. This holds true for breastfeeding as well, as we discuss in more detail below.
Food Allegy Prevention

in St. Louis, Missouri

Common food allergens: peanuts, wheat, soy, cow's milk, eggs, fish, shellfish, tree nuts, sesame

How to Prevent Food Allergies in Infants

Your infant is at a higher risk of food allergy if a parent or a sibling has an allergic condition. Even if allergies do run in your immediate family, it’s important NOT to avoid allergenic foods early in the child’s development. However, if allergies do run in your family, you should proceed with caution when introducing new foods to your infant and be on the lookout for allergic reactions.


Mother’s should not avoid allergenic foods when breastfeeding. As with pregnancy, there is no evidence that avoiding allergenic foods while breastfeeding prevents the development of allergic conditions. In fact, clinical data suggests that breast milk is the least likely feeding method to trigger an allergic reaction in infants. Breastfeeding is also beneficial in that breast milk may reduce the risk of cow’s milk allergy, as well as other symptoms of allergies and asthma.

Formula Feeding

Breastfeeding is the recommended method of nourishing your infant during the first four to six months, but if you’re unable to breastfeed, cow’s milk and soy formulas are common substitutes. However, cow’s milk and formulas may be allergenic and should be avoided if your infant is at risk of food allergy or if an allergic reaction has been observed. Hydrolyzed formula is a hypoallergenic alternative.

How To Introduce Solid Foods To Babies For Allergy Prevention

You can typically start to introduce solid foods to babies at four to six months depending on your child’s developmental readiness. The earliest foods that parents introduce often include fruits, vegetables and cereal grains, but allergenic foods like egg, dairy, peanut, tree nuts, fish, and shellfish should also be introduced early. In fact, delaying the introduction of allergenic foods may increase your child’s risk of developing allergies.

New foods should be introduced one at a time every three to five days to monitor your baby for allergic reactions, especially if allergies run in your family. If an allergic reaction does occur, it will usually do so within minutes of eating the trigger food. However, symptoms may be delayed by up to a few hours in some cases. Eczema (rash) is the most commonly recognized allergic response in infants, but any of the following could indicate an allergic reaction:


  • Eczema
  • Stuffy nose
  • Sneezing
  • Teary eyes
  • Wheezing
  • Diarrhea
  • Swelling
  • General signs of discomfort
Food Allergy Prevention

in St. Louis, Missouri

Infant with eczema from food allergy reaction

Pediatric Food Allergy Testing

If you suspect a food allergy in your baby, the best course of action is to see an allergist to confirm a diagnosis. Self-diagnosing an allergy is not recommended due to false positives, and unnecessary food avoidance can cause more harm than good for your child.

Dr. Cajigal specializes in pediatric food allergy diagnostic techniques, including oral food challenges, skin testing, and blood testing.

Parents will sometimes seek allergy testing outside of the expertise of a board-certified allergist. Alternative methods can include massive screening tests done in supermarkets or drug stores, allergy testing through muscle relaxation, cytotoxicity testing, skin titration, and provocation testing, and others. In general, these alternative methods are not recommended, and they will not allow you to reliably pinpoint the cause of an allergic reaction in your child. Seeing an allergist is the surest method to get to the bottom of your child’s allergies and establish a formal diagnosis. You can learn more about certified baby food allergy test methods below.

Food Challenge

A food challenge involves feeding your child a small amount of the suspected food allergen in a supervised, medical setting. If the initial amount is tolerated, the ‘dose’ will be increased until an allergic response occurs, or until it’s confirm that your child is not allergic.

Skin Testing

Dr. Cajigal may suggest a food allergy skin-prick test, where small volumes of food allergens (and controls) are placed on your child’s skin and pricked with a sterile needle. After 20 minutes, the skin is re-examined for any bumps indicating an allergic reaction.

Baby Food Allergy Blood Test

A blood test can measure the amount of antibody circulating in the blood in reaction to the specific food allergen of interest. This confirmatory test is often used to rule out a suspected allergen if skin testing shows no response.

See a Food Allergy Doctor

in St. Louis, Missouri

Infant getting a blood test for food allergy diagnosis

Infant Food Allergy Treatment

If your infant has food allergies, there will undoubtedly be many situations in your child’s life where they will be unable to control their environment or the foods that they’re exposed to. Depending on what food(s) your child is allergic to, there may be treatments available that can help minimize the severity of their allergic reactions and even enable them to safely ingest foods that they’re allergic to. You can learn more about allergy treatment options below.

Avoid Trigger Foods

The most important part of managing food allergies is to avoid trigger foods. Be sure to read food labels and always ask about ingredients when eating at restaurants with your child or when eating foods prepared by family or friends.

Have an Action Plan

If your child has a severe allergic reaction to certain foods, ensure that they have an anaphylaxis action plan and carry autoinjectable epinephrine (an EPI Pen) with them at all times in case of a severe reaction. Dr. Cajigal provides training to you and your children on how to navigate a serious allergic reaction.

Outgrowing Food Allergies

It’s common for children to outgrow their food allergies A food challenge and other formal allergy testing methods can help confirm if your child is no longer allergic to a particular food.

Oral Immunotherapy

Oral immunotherapy is an emerging treatment in which gradually increasing amounts of an allergen are fed to an individual with food allergies. The goal of oral immunotherapy is to increase the amount of exposure to an allergen that the individual can tolerate. For example, someone with a peanut allergy may be given a very small amount of peanut protein to build up a tolerance to peanuts over time. Oral immunotherapy has not been shown to cure allergies, however it can greatly reduce the severity of allergic reactions. Recent evidence suggests that the earlier your child starts with oral immunotherapy, the more effective it is.

We hope you’ve found this information helpful. Get in touch with us at St. Louis Family Allergy to learn more about food allergy prevention for your child. We’re looking forward to your visit.


[1] American College of Allergy, Asthma & Immunology: [2] Asthma and Allergy Foundation of America:
More Specialties


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Visit Pediatric Food Allergist Dr. Sonia Cajigal of St. Louis Family Allergy in St. Louis, Missouri

Pediatric Food Allergist Dr. Sonia Cajigal

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"Dr. Cajigal was friendly, professional, and informative. She took the time to explain the tests and what was going on with my allergies. She is so knowledgeable and really cared about how I was feeling. I would highly recommend this practice if you suffer from allergies and asthma."

- Sue D, July 2020

“Dr Cajigal is a great listener. She trusts her patients instead of treating them as if they are not the experts of their own bodies. I really appreciate that (many doctors do not have that quality). She also immediately treats the symptoms instead of waiting to see if things clear. I use her for my children and myself. We have never left her office feeling as if it was a waste of time.”

– Stephanie, August 2020

"Great Allergist!"

- Ann H, December 2018

"She is the best."

- Stephen W, June 2020

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