Breastfeeding and Milk Protein Allergy: Feeding a Baby Who Can't Tolerate Dairy
Breastfeeding is a cherished bond between mother and child, providing essential nutrients and fostering a strong immune system in infants. However, when a baby shows signs of milk protein allergy (MPA), it can be concerning and confusing for parents.
MPA, also known as cow’s milk protein allergy (CMPA), is one of the most common food allergies affecting infants. It occurs when a baby’s immune system reacts adversely to the protein molecules found in cow’s milk, which can be transferred through breast milk.
In this post, we will dive into managing MPA while breastfeeding, help you better understand the allergy, recognize symptoms, and navigate dietary adjustments to ensure both mother and baby thrive during this critical period.
Whether you're just beginning to suspect MPA in your child or seeking guidance on managing dietary changes, my goal is to provide clarity and support for breastfeeding mothers facing this challenge.
What is Milk Protein Allergy?
Milk protein allergy (MPA), also known as cow’s milk protein allergy (CMPA), is an adverse reaction to the protein molecules found in cow’s milk, which include whey and casein. This immune response can manifest in various forms, ranging from mild discomfort to severe allergic reactions in some cases.
MPA is more common among males and those who have atopic conditions such as eczema and asthma. It is also more common in formula-fed babies; only about 0.5% of exclusively breastfed infants show reactions to cow’s milk protein compared to 2%- 7.5% of formula-fed infants.
What are the Different Types of Milk Protein Allergy?
There are two primary types of milk protein allergy: IgE-mediated and non-IgE-mediated. While only about 3% of infants have a MPA, about 60% of those babies have an IgE-mediated allergy that involves the immune system producing antibodies called immunoglobulin E (IgE) in response to milk proteins.
Non-IgE-mediated allergy, on the other hand, involves delayed reactions that typically affect the digestive system, skin, or other organs. These reactions may manifest as eczema, reflux, or other GI upset. Often, GI symptoms include increased gas, diarrhea, abdominal pain, and bloody stools. Many times, non-IGE-mediated allergy can be misinterpreted as lactose intolerance, which is not a true milk allergy, but rather a condition involving difficulty digesting lactose, a sugar found in milk and milk products.
Other non–IgE–mediated gastrointestinal food allergies include Food Protein-Induced Enterocolitis Syndrome (FPIES), Eosinophilic Oesophagitis (EoE), food protein-induced allergic proctocolitis (FPIAP), food protein-induced allergic enteropathy, and food protein-induced dysmotility disorders (gastro-oesophageal reflux disorder and constipation).
Signs and Symptoms of Dairy Allergy in Breastfed Babies
Most symptoms of MPA appear within the first few weeks of life. Symptoms of IgE-mediated allergy typically occur within a few minutes up to 2 hours after ingestion and can include immediate allergic reactions, including anaphylaxis, facial swelling, hives, wheezing, and trouble breathing. IgE-mediated symptoms can be fairly mild to severe, although severe reactions and symptoms of anaphylaxis are uncommon in infants.
Non-IgE-mediated allergic reactions usually have a delayed onset and occur about 2 hours after ingesting milk proteins. Symptoms typically involve the digestive system and may include gas, diarrhea, and mucousy or bloody stools. Non-IgE-mediated MPA most often involves the GI tract and causes bloody stools in an otherwise healthy, happy baby (FPIAP), although less often, it can also affect the skin and may lead to respiratory symptoms as well.
In my private practice as a pediatric registered dietitian, I get many questions from parents about baby rashes that occur when eating dairy. A dairy allergy rash in breastfed babies can present as eczema or hives, appearing shortly after breastfeeding if mom has consumed dairy products.
It is important to note that not all eczematous rashes or hives are related to MPA; however, if you have concerns about your baby’s symptoms, it is best to check in with your pediatrician or healthcare provider.
What is FPIES?
Food protein-induced enterocolitis syndrome (FPIES, is a non-IgE-mediated, severe allergy based in the gastrointestinal tract and sometimes referred to as “delayed food allergy” because it can cause severe vomiting and diarrhea 1 to 4 hours after a trigger food is ingested.
Cow’s milk, soy, rice, and oats are common trigger foods for FPIES. FPIES often develops during a baby’s first year of life when the baby is starting solids, and most children outgrow the condition by age 3 or 4.
What is the Difference Between Milk Protein Allergy and Milk Protein Intolerance?
A food allergy differs from a food intolerance. Food intolerances involve different parts of the immune system and occur when the body cannot properly digest specific food components, such as lactose in dairy products or gluten in wheat. This can lead to symptoms such as bloating, gas, diarrhea, or stomach cramps.
Milk protein allergy involves the immune system reacting to milk proteins, whereas milk protein intolerance is a non-immunological response characterized by difficulty digesting lactose, the sugar in milk. The symptoms can be similar, but are caused by different mechanisms.
How Long Does Dairy Stay in the System When Breastfeeding?
Dairy proteins can remain in breast milk for up to 48-72 hours after consumption. This means that, for most moms, eliminating dairy from the diet is essential for evaluating and managing signs of CMPA in a breastfed baby.
I Accidentally Ate Dairy While Breastfeeding a Milk Allergic Baby. Now What?
If dairy is accidentally consumed during an elimination diet, observe your baby for any symptoms of an allergic reaction and consult with your healthcare provider if the baby develops any symptoms. Your doctor may recommend supportive care or medication depending on the severity of the reaction.
Because milk proteins can remain in breast milk for up to 72 hours, you may need to provide your baby with previously expressed breast milk or a dairy-free infant formula until you can resume breastfeeding. If this is the case for you, be sure to continue pumping on a normal feeding schedule to maintain your milk supply.
Cow’s Milk Protein Allergy Foods to Avoid While Breastfeeding
Because only a tiny amount of cow’s milk proteins are transferred to a baby while breastfeeding, a dairy-free diet for mom is not always necessary. Many babies can continue breastfeeding while their mom eats a diet that includes dairy. There are some instances, though, when a mom may need to restrict dairy from her diet.
According to recent research, “current clinical practice recommendations advise a 2–4 week trial of maternal cow's milk dietary elimination for:
a) IgE-mediated CMA only if the infant is symptomatic on breastfeeding alone
b) non-IgE-mediated associated symptoms only if the history and examination strongly suggest CMA
** Determining if a breastfeeding mother needs to follow a dairy-free diet is best made in conjunction with a pediatrician or allergy specialist.**
If recommended, a milk protein allergy breastfeeding diet involves eliminating all sources of cow’s milk protein from your diet while making sure you are getting enough nutrition from other food sources and/or supplements. After the 2-4 week trial, it is recommended to reintroduce dairy into the mom’s diet for one week to determine if symptoms return in the baby.
Another important point to keep in mind is that most patients with MPA do not tolerate milk from sheep and goats.
To prevent triggering allergic reactions, mothers should avoid consuming all dairy products, including:
Milk (including milk from cows, sheep, and goats)
Cheese, including cream cheese
Yogurt
Ice cream
Sour Cream
Products containing milk powder, whey, or casein (often in foods labeled with “protein”)
*** In addition to dairy food products, a soy protein-free diet may also be needed if your child is diagnosed with MPA. This is because ~50% of infants with MPA may also react to the proteins in soy. **
While these items are removed from your diet, remember to continue eating a well-balanced, nutrient-dense diet and taking a pre- or post-natal vitamin to make sure you are getting adequate vitamin D and calcium supplementation. You may want to contact a registered dietitian who can help you avoid nutrient gaps as you navigate these dietary restrictions.
Reintroducing Dairy to Baby with Milk Protein Allergy
Reintroducing dairy to a baby with milk protein allergy should be done under the guidance of a health care professional, typically a pediatrician or allergist. It typically involves gradually introducing small amounts of dairy to assess tolerance levels.
The good news is that by age 5 years of age, 50% of those who develop IgE-mediated CMPA have developed tolerance.
A food ladder is a stepwise progression of a particular food, moving from extensively heated to less heated forms of the food. This approach has been widely adopted for the gradual introduction of milk for patients with non-IgE-mediated CMA, excluding FPIES.
A milk ladder can then help you reintroduce dairy to a baby with milk protein intolerance and ensure that the child tolerates dairy well and has a positive experience with reintroduction.
Navigating milk protein allergy while breastfeeding can be difficult, but with patience, vigilance, and informed decision-making, we can ensure a healthy baby and a diet for mom that supports both her health and that of her baby. Consulting with an allergy specialist or registered dietitian specializing in food allergy can provide tailored guidance as well, and help you for manage this issue with ease. Take heart! When you understand the symptoms, dietary adjustments, and reintroduction protocols, you’ll feel more confident in navigating this challenge while fueling your child’s growth and well-being.
If you’re interested in learning more about how and when to integrate foods into your baby's diet, as well as reducing the risk of food allergies for your baby, check out my new baby-led feeding cookbook!
It helps reduce the risk of developing food allergy during infant feeding and makes starting solids easy, joyful, and delicious for the baby and the entire family as well.
And if you're looking for personalized nutrition support for your babies or kids, I am currently accepting new clients in my virtual private practice.
Thanks for reading!