food allergies

Infant Food Allergies

Nutrition plays a vital role in infant growth and development.  Unfortunately, a record 25% of parents report infant food intolerance and allergy issues.  Symptoms that arise from these disorders – colic, vomiting, diarrhea, reflux, bloody stool, failure to thrive, eczema, and more – take their toll on the entire family.  Below, we break down these food sensitivity disorders.  It is critical to recognize that each one of these disorders can present from maternal dietary proteins transferred to breast milk.  Understanding which category your little one falls under, particularly for non-IgE mediated, can help guide elimination and reintroduction strategies.  

2 Main Categories 


1) Immunoglobulin E (IgE) mediated:

The immune system makes IgE antibodies which react to a certain food or foods.  IgE mediated allergic reactions can involve the lungs, eyes, mouth, intestines, brain, heart, or skin and range from mild to life-threatening.  The most common IgE-related allergens in infants are milk, soy, eggs, peanuts, tree nuts, and wheat.  These food sensitivities can be determined through skin or blood tests, however they can be less accurate in patients under 6 months old [1].  


2) Non-IgE mediated:

Here, portions of the immune system may react to offending foods without involving IgE antibodies.  A majority of non-IgE mediated allergic reactions occur in the digestive tract, however they may present in nearly any part of the body.  Subcategories of non-IgE mediated allergies include FPIES, FPIAP, and EoE, which are based mainly on the location of the reaction and/or the symptoms it causes. 

Food protein-induced enterocolitis syndrome (FPIES)

FPIES is characterized as a gastrointestinal reaction to foods such as milk, soy, and wheat.  Here, a large portion of the gastrointestinal tract is affected which leads to severe reactions such as vomiting, diarrhea, bloody stool, and dehydration.  FPIES symptoms may not occur immediately after consumption and do not show up on standard allergy tests.  Infants with FPIES who consume allergen-containing breast milk or formula on a regular basis commonly experience increasingly severe symptoms leading to poor growth.  These symptoms can mimic sepsis (infection) which may delay proper diagnosis [2].  More information can be found through the FPIES Foundation.  


Food protein-induced allergic proctocolitis (FPIAP)

FPIAP also stems from an allergy to proteins in breast milk or formula, however the reaction occurs in the lower intestine.  Symptoms can include colic, diarrhea, vomiting, anemia, and stool with mucous.  Similar to FPIES, elimination of the offending food from the mother’s diet can alleviate symptoms.  Infants typically become tolerant to the allergen by one to three years of age [2].  Dig deeper into common triggers and course of action at


Eosinophilic esophagitis (EE or EoE)

This disorder is described by its name.  It is caused by an unusually high number of eosinophils (a type of white blood cell) and inflammation of the esophagus.  These white blood cells may be present due to allergies, acid reflux, or injury.  While symptoms vary by age and per patient, infants and toddlers commonly present with irritation in the esophagus which leads to feeding issues and poor weight gain [3].  This closely mimics the symptoms of gastroesophageal reflux disease (GERD) which can cause misdiagnosis.  Read more from the APFED Foundation


  1. Höst, Andrae, et al. "Allergy testing in children: why, who, when and how?." Allergy 58.7 (2003): 559-569.

  2. Nowak-Węgrzyn, Anna. "Food protein-induced enterocolitis syndrome and allergic proctocolitis." Allergy and asthma proceedings. Vol. 36. No. 3. OceanSide Publications, 2015.

  3. Kagalwalla, Amir F., et al. "Effect of six-food elimination diet on clinical and histologic outcomes in eosinophilic esophagitis." Clinical gastroenterology and hepatology 4.9 (2006): 1097-1102.