How Do I Know if My Baby Has Food Allergies?

Breastfeeding Your Baby With Food Reactivity

When something is wrong with your baby, it feels like the world stops. Nothing matters more than figuring out what's causing their discomfort. Their health and happiness becomes your singular focus.

That's exactly why trying to decode what's happening with babies who have food reactivity can be so challenging. There are countless symptoms, and the internet is full of conflicting information that leaves you more confused than when you started.

This is precisely why Free to Feed exists. We recognized a critical gap in science-based information about babies with food reactivity, so we've built a community of support grounded in real research for this growing concern.

Sometimes the medical field defaults to formula recommendations, which works for some families. But if your heart is set on breastfeeding, we want you to know that continuing to nurse your baby with food reactivity is absolutely possible and we're here to help you succeed.

A crucial point: Your baby is not allergic to your breast milk. Let us say that again: your baby is NOT allergic to your breast milk. They're reacting to specific food proteins that pass through your breast milk. This distinction matters because it means you have options.

Understanding Food Reactivity in Breastfed Babies

Research shows that the reactions babies most often experience are non-IgE mediated food allergies, which operate differently from the classic IgE-mediated reactions that require EpiPens and immediate medical attention [1]. Non-IgE mediated food allergies encompass delayed reactions that affect the gastrointestinal tract and/or skin and often don't have the same trigger foods as their IgE-mediated counterparts.

Food proteins such as cow's milk, egg, soy, and wheat are detectable in breast milk for many hours after a parent consumes them [2]. While most babies tolerate these proteins without issue, some develop immune responses that manifest as various symptoms [3].

Rather than providing a generic list of "top allergens," we've learned that the foods most likely to trigger vomiting are different from those that cause bloody stools, which are different again from those that lead to skin reactions. That's why our food reactivity experts use our comprehensive database during 1:1 consultations to identify the specific triggers most likely to cause the exact symptoms your family is navigating.

The Symptom Spectrum: What Food Reactivity Looks Like

Upper GI Reactivity

Excessive spit-up/reflux: While all babies spit up, research has found that gastroesophageal reflux was associated with cow's milk allergy in 41.8% of cases in infants under 12 months [4]. When spit-up becomes projectile, frequent, or seems to cause pain, food reactivity may be the underlying cause.

Chronic congestion: That persistent stuffy nose might not be a cold. Food proteins can trigger inflammatory responses in the upper respiratory tract, leading to ongoing congestion that doesn't resolve with typical treatments.

Painful spit-up/reflux: When your baby arches their back, cries during or after feeding, or seems genuinely distressed by reflux episodes, this suggests more than simple spitting up.

"Silent reflux": Perhaps the trickiest to identify, this happens when stomach contents come up but are swallowed back down. You might notice your baby making swallowing motions, facial grimaces, or showing feeding aversion without obvious spit-up.

For families dealing with reflux symptoms, our Reflux Relief course provides comprehensive guidance on causes, solutions, and ongoing support. You can also read more in our detailed blog post on helpful information about reflux.

Lower GI Reactivity

Blood in stool: A recent prospective study found that food protein-induced allergic proctocolitis (FPIAP) had an incidence of 17% over 3 years in healthy infants [5]. Even small streaks of blood warrant investigation, as this often indicates inflammation in the lower digestive tract.

Excessive or concentrated mucus in stool: While some mucus is normal, consistently thick, stringy, or abundant mucus suggests intestinal irritation.

High calprotectin levels in stool: This laboratory marker measures inflammation in the intestines and can help differentiate between food reactivity and other causes of digestive symptoms.

Diarrhea and constipation: Food reactivity can swing both ways with some babies experiencing frequent, loose stools while others become severely constipated as their digestive system struggles with inflammatory responses.

Our Alleviating Allergic Proctocolitis Symptoms course specifically addresses lower GI symptoms, and you can explore our diaper analysis resources for detailed guidance on what to look for.

Skin Reactivity

Hives: These raised, red welts typically indicate IgE-mediated reactions and require immediate attention, especially if they appear rapidly after feeding.

Eczema: Research demonstrates that food proteins in breast milk can be found in sufficient amounts to elicit eczema exacerbation in some sensitized infants [3]. Persistent dry, red, scaly patches, especially on the face and in skin creases, may be food-related.

Other rashes: Various rashes can appear anywhere on the body, from fine bumps to angry red patches. Each pattern can provide clues about potential triggers.

To see what food-triggered skin reactions actually look like, check out our visual guide with real family photos showing various presentations of food-related eczema.

Secondary Symptoms

These symptoms often develop as a result of the primary reactions listed above:

Feeding refusal: When eating consistently causes discomfort, babies may start refusing feeds or showing anxiety around feeding time.

Weight gain issues: Chronic inflammation, excessive spit-up, or feeding difficulties can impact a baby's ability to gain weight appropriately.

"Colic" or inconsolable crying: Studies show that in breastfed infants, infantile colic a single issue is seldom caused by reactivity, but the association exists. Prolonged crying episodes, especially if they coincide with other symptoms, may indicate underlying food reactivity.

Sleep disturbances: Digestive discomfort, skin irritation, or reflux can significantly disrupt sleep patterns for both baby and family.

For families dealing with severe vomiting reactions, our FPIES course provides specialized guidance for this form of food reactivity.

The Diagnosis Challenge When Baby Has Food Allergies

Getting a definitive diagnosis of food reactivity in babies is notoriously difficult. There are currently no recommended biomarkers for diagnosis across the spectrum of non-IgE mediated allergies, which includes breastfeeding infants presenting with delayed symptoms [6].

Traditional allergy tests (skin prick tests or blood work) typically aren't performed until babies are at least 6 months old, and even then, they will not show positive for non-IgE mediated reactions which cause the symptoms listed above. Learn more about testing options and the nuance here.

The most reliable "test" remains carefully monitored elimination diets followed by controlled reintroduction. If symptoms improve when you remove a suspected food and return when you reintroduce it, you've likely identified a trigger.

Ready to Get Answers?

Take our food reactivity quiz to assess whether you're likely dealing with food reactivity and get personalized next steps based on your specific situation.

Join our free symptoms training where we'll cover:

• Allergy & Intolerance: The difference between food allergies and food intolerances, and which one you're likely experiencing

• Food Allergy Symptoms: Common symptoms and how to differentiate between food reactivity and other issues your baby might be experiencing

• How Diet Impacts Breast Milk: How your diet affects the proteins in your breast milk and whether it can cause reactions in your child

  
  

Trust Your Instincts

We can't say this enough: you know your baby best. When something doesn't "feel right," it probably isn't. It can be frustrating to hear medical professionals say "don't worry, they're growing fine" when you can see your baby is struggling. Trust your parental instincts and advocate for your little one.

Finding answers often requires a team approach, and that's where we come in. We'll continue providing science-based information and working alongside your medical team to find solutions that work for your family.

Professional Support When You Need It

Consider booking a 1:1 consultation if you feel like you're losing your mind trying to figure out what's causing your baby's symptoms. Our food reactivity experts will work with you to develop a personalized elimination and reintroduction plan, using our comprehensive food reactivity database to target the most likely triggers for your specific symptom pattern.

We're here to support you and guide you through this journey. We've been in your shoes, and we know this road all too well. You're not alone in this.

References:

1. Meyer, R., et al. "Diagnosis and management of Non‐IgE gastrointestinal allergies in breastfed infants—An EAACI Position Paper." Allergy, vol. 75, no. 1, 2020, pp. 14-32.

2. Palmer, D. J., et al. "Food Proteins in Human Breast Milk and Probability of IgE-Mediated Allergic Reaction in Children During Breastfeeding: A Systematic Review." The Journal of Allergy and Clinical Immunology: In Practice, vol. 10, no. 4, 2022, pp. 912-921.

3. D'Auria, E., et al. "Presentation and Management of Food Allergy in Breastfed Infants and Risks of Maternal Elimination Diets." The Journal of Allergy and Clinical Immunology: In Practice, vol. 7, no. 8, 2019, pp. 2274-2281.

4. Iacono, G., et al. "Gastroesophageal reflux and cow's milk allergy in infants: A prospective study." The Journal of Allergy and Clinical Immunology, vol. 97, no. 3, 1996, pp. 822-827.

5. Vandenplas, Y., et al. "Perspectives on Non-IgE-Mediated Gastrointestinal Food Allergy in Pediatrics." Journal of Asthma and Allergy, vol. 16, 2023, pp. 253-267.

6. Salvatore, S., et al. "Cow's Milk Allergy or Gastroesophageal Reflux Disease—Can We Solve the Dilemma in Infants?" Nutrients, vol. 13, no. 2, 2021, pp. 297.