It’s estimated that 40% of children in the US are impacted by multiple food allergies.¹ In this article, we will focus on infants and the presentation of food allergies, diagnosis, and alternative feeding options to consider for infants who are impacted.

Infant Food Allergies Defined

Food allergies occur when the immune system responds abnormally to a specific food. This immune-mediated response will reoccur every time that certain food is consumed. Note that food allergies are different from food intolerance (a non-immune-mediated reaction) because food intolerance doesn’t involve the immune system.²

There are 4 kinds of immune-mediated reactions²:

•  IgE-mediated
•  Non-IgE-mediated
• Mixed IgE- and non-IgE-mediated
• Cell-mediated

Identifying Symptoms and Diagnosis

Undiagnosed food allergies can be extremely harmful to infants, so recognizing the symptoms and providing an early diagnosis is key.

• Common symptoms for IgE-mediated immune response: urticaria, angioedema, vomiting, diarrhea, oral itching, and/or anaphylaxis where reaction times can occur within minutes or up to 2 hours.³
• Common symptoms for non-IgE-mediated immune response: diarrhea, rectal bleeding, food refusal, weight loss, failure-to-thrive, gastroesophageal reflux, abdominal distension, irritability, and/or eczema where reaction times often occur over 4 to 6 hours.³
• Common symptoms for cell-mediated immune response: digestive issues, skin reactions, rectal bleeding, and/or respiratory problems where the onset of symptoms can occur more than 8 hours after ingestion of the offending food.³

Diagnosing food allergies can include reviewing the patient’s medical history, performing a medical examination, eliminating certain foods from the breastfeeding parent’s diet to see if symptoms cease or persist, or a trial of hypoallergenic formula, if necessary. Note: for IgE-mediated food allergies, predictive value tests can help physicians confirm a food allergy diagnosis, but these tests are not considered diagnostic on their own.²

Feeding Options 

Breastfeeding is the optimal nutrition source for infants. However, it can be challenging to manage food allergies in breastfeeding infants, as there is a limited amount of data published on the presence of food proteins in human milk, and food elimination diets may adversely impact the nutritional status of the breastfeeding parent. If parents choose to continue breastfeeding and try an elimination diet, they should work closely with their healthcare provider throughout the process. If parents decide to pursue formula-feeding options instead, finding a nutrition product that works for their infant with food allergies may require trying multiple formulas.

Depending on the infant’s immune reaction, here are some possible formula-feeding options to consider^2,4:

• For IgE-mediated immune responses:
  • Soy protein-based formula
  • Extensively hydrolyzed protein-based formula
  • Amino acid-based formula
• For non-IgE-mediated immune responses, mixed IgE- and non-IgE-mediated immune responses, and cell-mediated immune responses:
  • Extensively hydrolyzed protein-based formula
  • Amino acid-based formula

Final Thoughts

Developing the skills and awareness to recognize how infant food allergies present in our patients can help remediate an infant’s immune response. By providing the feeding options that best address each type of food allergy, you can help your patients and their caregivers enjoy a higher quality of life.  

References: 1. Warren CM, et al. Ann Allergy Asthma Immunol. 2023;130(5):637-648.e5. 2. Boyce JA, et al. J Allergy Clin Immunol. 2010;126(6 suppl):S1-S58. 3. National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee on Food Allergies: Global Burden, Causes, Treatment, Prevention, and Public Policy, Oria MP, Stallings VA, eds. Finding a Path to Safety in Food Allergy: Assessment of the Global Burden, Causes, Prevention, Management, and Public Policy. Washington (DC): National Academies Press (US); November 30, 2016. 4. American Academy of Pediatrics Committee on Nutrition. Food Allergy. In: Kleinman RE, Greer FR, eds. Pediatric Nutrition. 8th ed. Itasca, IL: American Academy of Pediatrics, 2019:981-1002.