Cow's milk allergy (CMA) is one of the more common food allergies found in children. Worldwide, approximately 3% of infants/children suffer from CMA^.1-9 We will discuss the presentations of CMA, how to diagnose it, and alternative feeding options for infants who may be impacted.

What Are Food Allergies?

Food allergies occur when the immune system responds abnormally to a food allergen. This immune-mediated response will reoccur every time that allergen 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.¹⁰

CMA reactions can be either immunoglobulin E (IgE) mediated or non-IgE-mediated:

• IgE-mediated reactions: The milk allergen binds to 2 IgE molecules, which releases histamine and triggers allergic symptoms¹¹
• Non-IgE-mediated reactions: It has yet to be discovered exactly how these reactions occur, but they're thought to be cell-mediated^11-12

Identifying Symptoms and Diagnosis

Undiagnosed or untreated CMA can lead to serious or even fatal consequences, so it’s important to be able to recognize symptoms when you see them.

• Common symptoms for IgE-mediated immune response: Urticaria, angioedema, vomiting, diarrhea, oral itching, and anaphylaxis. Reactions typically happen quickly, within minutes or up to 2 hours. In infants, skin reactions (urticaria, rash) are more common, but other symptoms may include vomiting, diarrhea, oral itching, and in rare occasions, anaphylaxis¹¹
• Common symptoms for non-IgE-mediated immune response: Diarrhea, food refusal, failure to thrive, gastroesophageal reflux, abdominal distension, irritability, or eczema. Reactions are typically delayed, occurring 4 to 6 hours after exposure, but in some instances, it may take days or weeks. Symptoms are usually gastrointestinal in nature (potentially including diarrhea, constipation, gastroesophageal reflux, and abdominal distention), however, other organ systems may be involved¹¹

Diagnosing food allergies can include reviewing the patient’s medical history, performing a medical examination, eliminating certain foods from the patient’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.¹³

Feeding Options For Infants With CMA

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 breast milk. In some cases, breastfeeding parents may need to eliminate foods from their diets to try to determine the allergen. If food allergy symptoms continue during breastfeeding, infants may need to transition to a formula feeding option. On the other hand, formula-fed infants presenting with CMA symptoms may be reacting to cow's milk protein in their formula.

Here are some formula options to consider, according to the infant’s immune reaction:^10,14

• Formula feeding options for IgE-mediated cow’s milk allergy:
  
  • Extensively hydrolyzed protein-based formula
  • Amino acid-based formula
  • Soy protein-based formula
• Formula feeding options for non-IgE-mediated cow’s milk allergy:
  • Extensively hydrolyzed protein-based formula
  • Amino acid-based formula
• Formula feeding options for eosinophilic esophagitis (EoE):
  • Amino acid-based formula

Final Thoughts

Identifying the symptoms of CMA and the feeding options to recommend can provide children with the nutrition they need to grow and thrive. Please join me in spreading awareness of how CMA presents in infants.

References: 1. Kattan J. Curr Allergy Asthma Rep. 2016;16(7):47. 2. Boyce JA, et al. Nutrition. 2011;27(2):253-67. 3. Fiocchi A, et al. Pediatr Allergy Immunol. 2010;21(Suppl 21):1-125. 4. Lee AJ, et al. Asia Pac Allergy. 2013;3(1):3-14. 5. Venter C, et al. Pediatric Clinics. 2011;58(2):327-49. 6. Osborne NJ, et al. J Allergy Clin Immunol. 2011;127(3):668-76. 7. Schoemaker AA, et al. Allergy.2015;70(8):963-72. 8. Bock S, et al. Pediatrics. 1987;79(5):683-688. 9. Gupta RS, et al. Pediatrics. 2011;128(1):e9-e17. 10. Boyce JA, et al. J Allergy Clin Immunol. 2010;126(6 suppl):S1-S58. 11. 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. 12. Soyyılmaz, et al. Nutrients. 2021;13(8):2737. 13. Boyce JA, et al. J Allergy Clin Immunol. 2010;126(6):S1-S5. 14. 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.