When your baby has food allergies it can stir up a whirlwind of information. Or maybe it feels like a lack of information! It’s a stressful time that you want to fix– fast.
There are many factors at play when it comes to infant food allergies. First, it’s very important to differentiate infant food allergies from infant food intolerances.
According to the American Academy of Allergies, Asthma, and Immunology (AAAAI), infant food intolerances occur when the digestive system cannot break down certain foods.  This can be caused by food sensitivities or enzyme deficiency. Read more about types of enzymes and tests here, as enzyme deficiencies can be tested for.
AAAAI states that infant allergies cause the immune system to overreact as though something is invading the body. One type causes an overproduction of antibodies called immunoglobulin E (IgE). Having IgE antibodies in excess causes an allergic reaction.  These are called IgE allergies.
Another type of allergic reaction occurs without producing IgE antibodies but still alarms the immune system. For this exact reason, they are called Non-IgE allergies. Non-IgE allergies are the most common offender for infant reactions to proteins in breast milk or solids.
Below we’ll further discuss these two categories of infant food allergies: IgE and Non-IgE. Non-IgE also has subcategories that we’ll touch on.
The Basics of IgE-Mediated Infant Food Allergies
The immune system is very complex and works to protect our bodies against bacteria, viruses, and more. In the case of food allergies in infants, the immune system is triggered by food proteins that enter through breast milk or solids.
We know that a breastfeeding parent passes food proteins to her baby while nursing. Sometimes the immune system disagrees with certain food proteins. This causes an allergic reaction causing the body to go into overdrive, fighting off the “invader” by creating IgE antibodies.
Overproduction of IgE antibodies causes an allergic reaction that can involve the lungs, eyes, mouth, intestines, brain, heart, or skin and range from mild to life-threatening. IgE-mediated food allergy is a leading cause of anaphylaxis, a severe, potentially fatal allergic reaction presenting to emergency departments. 
IgE allergies are the scary ones you think of when someone eats a peanut and then all of a sudden can’t breathe. It’s terrifying to think of this happening to your baby.
The most common IgE-related allergens in infants are milk, soy, eggs, peanuts, tree nuts, and wheat. Finding out if your baby has an IgE allergy can be a challenge. Skin prick tests or blood tests are not commonly performed until the baby is at least 6 months, as results are often inaccurate at younger ages. 
A recent study in 2018 about skin prick testing states “caution should be made when interpreting results and only suspected food allergens should be tested since food skin testing has a low specificity.” 
It can take time and a lot of patience to figure out IgE allergies in your baby. Stay strong and work with your baby’s doctor by providing a detailed history of previous reactions and symptoms.
If you need help with:
Documenting your diet while breastfeeding
Keeping track of diaper pictures
Logging your baby's reaction
Keeping track of ladders when reintroducing allergens
Tracking elimination foods
Download the Free to Feed App here!
This app was designed to help nursing families with babies that have infant food allergies or intolerances. The app can be shared with medical providers to help aid in the process of finding the trigger foods your baby is reacting to.
The Other Infant Food Allergy: Non-IgE Mediated
While these reactions don’t overproduce IgE antibodies, they can still cause serious problems for infants and their families by bothering other parts of the immune system. A majority of non-IgE-mediated allergic reactions occur in the digestive tract, but they may present in any part of the body. Like IgE allergies, they can cause an array of symptoms including, colic, vomiting, diarrhea, bloody or mucousy stools, and failure to thrive.
Subcategories of Non-IgE Mediated Infant Food Allergies
Subcategories of non-IgE mediated allergies include food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), and eosinophilic esophagitis (EE or EoE). These names are based mainly on the location of the reaction and/or the symptoms it causes.
Below we’ll break down the basics of each.
Food protein-induced enterocolitis syndrome (FPIES)
FPIES is a non-immunoglobulin IgE-mediated reaction to food. It’s characterized by gastrointestinal symptoms including vomiting, diarrhea, bloody stools, and dehydration. Diagnosis can be challenging due to a lack of disease biomarkers.
According to the FPIES Foundation, symptoms may not be immediate like other typical food allergies. “There is a characteristic delay of two to three hours before the onset of severe and repetitive vomiting and diarrhea. Many infants who are eventually diagnosed with FPIES are initially suspected to have severe infection or sepsis.”
When medical professionals think severe infection or sepsis it can lead to a longer road in getting the proper diagnosis as medical professionals don’t assume FPIES. Again, remember to work hard at monitoring your own diet and working with your medical team.
Food protein-induced allergic proctocolitis (FPIAP)
FPIAP occurs in the lower intestines and causes symptoms in babies such as; colic, diarrhea, vomiting, anemia, and mucousy stools. Diet elimination from a breastfeeding parent can reduce symptoms, but like the other non-IgE mediated allergies, it can take a while to figure out what is causing the harm to your baby.
FPIAP usually has a favorable prognosis with the majority of infants growing out of this allergy by 1 year in age.  You have to stay diligent with your diet restrictions, but you can do it if you’re determined to breastfeed.
Eosinophilic esophagitis (EE or EoE)
Eosinophils are a special type of white blood cell part of the immune system meant for protecting us. EE or EoE marks a higher number of eosinophils than usual on a blood test, causing disorders of the esophagus. Infants and toddlers present with irritation in the esophagus which leads to feeding issues and poor weight gain.
EoE may cause trouble swallowing, food impaction, heartburn, vomiting, abdominal pain, feeding difficulties, or failure to thrive. This can lead to misdiagnosis of gastroesophageal reflux diseases (GERD) as symptoms are similar.  Unlike other non-IgE allergies, EOE can be tested via scope with biopsy or blood test.
Work with medical professionals and trust your own gut, because you know your baby and you can find solutions that work for both of you.
What You Need to Understand With Infant Allergies
After going through pregnancy and giving birth, the last thing you want is another concern to worry about. We won’t sugar coat it––infant allergies are a hurdle to overcome. It takes patience and perseverance to continue to find the reasons why and what your infant is reacting to.
It can take both you and your medical professionals doing diligent work at noticing trends and focusing on your baby's symptoms and reactions to what you eat while breastfeeding.
If you're on a mission to breastfeed your baby with food allergies, then Free to Feed is here to help you!
Schedule a one-on-one consultation to learn more about the steps you can take to help you and your baby!