Milk. Does it always do a body good? Nope, not always. There are certain instances in which children and/or adults cannot tolerate cow’s milk or dairy products. Usually, it’s due to an allergy, known as cow’s milk protein intolerance (CMPI), or due to a malabsorption issue, termed lactose intolerance. Unfortunately, these two separate diagnoses are often confused, and there is a lot of misinformation out there. I hope to shed some light on this important topic.
Cow’s Milk Protein Intolerance (CMPI) and Cow’s Milk Protein Allergy (CMPA) are medical terms used interchangeably. This is defined as an abnormal response by the body’s immune system to the proteins found in cow’s milk. It mainly occurs in young infants. Therefore, caregivers need to be aware of it to monitor their baby for symptoms and call their pediatric healthcare provider right away with concerns.
Milk Allergy in Infants
What are the Different Types of CMPI?
There are two different types of CMPI: IgE-mediated, which causes an immediate reaction, and non-IgE-mediated, causing a delayed reaction. The two types have different symptoms associated with each. IgE, or immunoglobulin E, is an antibody normally found in humans that causes what you think of when you envision a true “allergic reaction” (anaphylaxis). IgE antibodies react to food proteins, causing a relatively quick and potentially severe reaction. In IgE-mediated cow’s milk protein allergy, symptoms usually start within two hours of drinking cow’s milk. In non-IgE-mediated CMPI, symptoms develop more slowly and occur later. They can occur after a couple of days or even up to one week after ingesting cow’s milk.
How Common is CMPI?
According to the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN), CMPI is believed to occur in about 2-3% of all infants in the United States and approximately 0.5% of breastfed infants. Therefore, breastfeeding is felt to be a protective mechanism in helping to prevent cow’s milk allergy. Risk factors for CMPI include having a parent or sibling with atopic or allergic disease (like asthma, eczema, and seasonal allergies).
What are the Symptoms of CMPI?
As with many things related to the human body, we cannot predict who will have a reaction and what symptoms they might display. As you can imagine, this can cause significant overwhelm, fear, and anxiety in caregivers. In addition, there is a wide range of possible symptoms, many of which are non-specific, and this may cause a delay in diagnosis.
Infants most commonly show signs that involve the skin (hives, rash, eczema) or the gastrointestinal system. Inflammation of the intestines, termed “colitis,” can lead to bloody stools. Sometimes red blood is visualized in the stool, but other times it is microscopic. These children may also develop vomiting, abdominal pain, mucous in their stools, diarrhea, bloating, and gas. Keep in mind that babies can also present with facial swelling, nasal congestion, coughing or wheezing, irritability, poor sleep, or poor growth due to feeding aversion or poor absorption of nutrients.
If your child has any of these signs or symptoms listed, contact your pediatric healthcare provider right away. With severe and concerning symptoms, seek emergent care or call 911.
How is CMPI Diagnosed?
CMPI is usually a “clinical diagnosis,” meaning it is determined through the caregiver’s history and your pediatric healthcare provider’s physical examination. The signs and symptoms, the timeline of events, and family history are very important. Stool studies may be performed to look for visible or microscopic blood and inflammation. We can often confirm a suspected diagnosis based on a baby’s response from eliminating cow’s milk from their diet.
How is CMPI Treated?
The mainstay treatment for CMPI is the elimination of cow’s milk entirely from the diet. Breastfeeding mothers must fully remove all dairy and soy (due to protein cross-reactions) from their diet, which will then subsequently eliminate those proteins from their breastmilk. In addition, the baby’s intestines may require time to heal. So there might be a delay of 1-2 weeks before symptoms resolve, whereas other babies seem to improve much more quickly.
Formula-fed babies can be switched to an extensively hydrolyzed formula (ex: Nutramigen or Alimentum), where the proteins are partially broken down so that they can be digested more easily. These formulas typically don’t cause an abnormal immune response. Much more rarely, it is necessary to use an amino acid-based formula (ex: Neocate or Elecare) that is broken down even further and made of the individual building blocks of proteins. However, these hypoallergenic formulas are more expensive and known to be less palatable than their milk-based formula counterparts.
What is the Prognosis for Children with CMPI?
Thankfully, the prognosis for CMPI is very good. Approximately 50% of infants will outgrow their allergy and be able to tolerate cow’s milk at one year, 75% by 3 years old, and 90% of children by the age of 6 years. Typically, pediatricians continue infants on a cow’s milk-free diet for 6–12 months. At that point, they may be challenged with cow’s milk and, if tolerated, can add milk back into the child’s diet safely.
What is Lactose Intolerance, and How is It Different than CMPI?
Lactose is a complex sugar found in cow’s milk. It is digested by the enzyme lactase. Lactose intolerance, also known as lactose malabsorption, is a reaction that is not immune-mediated. The most common type is Primary Lactose Intolerance, a hereditary condition where the small intestine doesn’t produce enough of the enzyme lactase to digest the sugar lactose. Essentially, those with primary lactose intolerance cannot fully digest milk, but they are not actually allergic to it.
The condition is usually harmless, but its symptoms can be uncomfortable. There are a few distinguishing factors between lactose intolerance and CMPI to note:
- Symptoms are typically localized to the gut, with abdominal discomfort, cramps, gas, bloating, nausea, and diarrhea. This is different than CMPI, which can present with symptoms outside of the gastrointestinal system.
- Lactose intolerance typically develops in older children and adults rather than in young infants like CMPI. Lactase production starts to decrease as children age. They become less dependent on dairy, usually after the age of 2.
- Those with lactose intolerance can often tolerate small amounts of dairy. For example, hard cheeses and yogurt typically contain less lactose compared to ice cream and milk. On the contrary, people with CMPI, an actual allergy to the milk protein, cannot tolerate any dairy (or dairy proteins, such as casein, whey, lactalbumin, etc.).
My Child is Allergic or Intolerant to Cow’s Milk — Now What?
Be reassured that cow’s milk and dairy products are not necessary components of a child or adult’s diet. Many people choose to consume a dairy-free diet, unrelated to their tolerance of dairy products. Interestingly, research suggests that a predominantly plant-based diet is a healthy option for preventing and reversing chronic diseases. In fact, anecdotally, when kids come into my pediatric office with vague, chronic abdominal pain or abnormal stools, I often ask them to remove dairy from their diet for two weeks as a trial. It doesn’t always fully resolve their symptoms. But almost always, there is an improvement in their symptoms.
There are alternative options to drinking cow’s milk and eating dairy products, should you or your child be unable to tolerate it or not want to consume it. Examples include soy (if not CMPI), almond, rice, hemp, pea, oat, coconut, and cashew milk. Remember, babies less than one year of age require breastmilk or infant formula as their primary nutrition source, not milk of any other kind. Be sure to consult your pediatric healthcare provider before making any changes to your child’s diet. Their nutritional status may need to be monitored more closely.