CMPA (Cow’s Milk Protein Allergy)

If your child has been diagnosed with a cow’s milk protein allergy (CMPA), or you think they might have CMPA, you might be feeling overwhelmed right now. Don’t worry, we’re here to help! In this blog post, we’ll give you all the information you need to know about CMPA.

What is CMPA?

Cow’s Milk Protein Allergy (CMPA) also commonly referred to as Cow’s Milk Allergy (CMA) is a reaction by the immune system to one or more proteins found in cow’s milk. The proteins that most commonly trigger an allergic reaction are beta-lactoglobulin and casein.

How common is CMPA?

CMPA Fact: Cow's Milk Protein Allergy (CMPA) affects 2 - 4.5% of infants under the age of one

Cow’s milk protein allergy is one of the most common food allergies in infants and young children. CMPA affects around 2 – 4.5% of infants under the age of one, and most children outgrow it by the time they reach school age. However, some children will continue to have CMPA into adulthood. 

What causes CMPA? 

The cause of CMPA is not fully understood, but it is thought to be due to a combination of genetic and environmental factors. Cow’s milk proteins are large and complex molecules that can be difficult for the digestive system to break down.

In some children, the digestive system is “leaky” and allows undigested proteins to pass into the bloodstream. The immune system then reacts to these proteins as if they were foreign invaders, leading to inflammation and the symptoms of CMPA. 

CMPA Symptoms

When a child with CMPA ingests cow’s milk, they may experience symptoms such as vomiting, diarrhea, eczema, hives, wheezing, and/or difficulty breathing. In severe cases, anaphylaxis can occur. According to the Guidelines for the diagnosis and management of cow’s milk protein allergy in infants, these are the symptoms of CMPA, along with additional symptom facts about CMPA.

Please note: The symptoms can vary between breastfed and formula-fed infants (see below).

Mild to Moderate Symptoms in Breastfed Infants

CMPA (Cow's Milk Protein Allergy) symptoms in breastfed infants infographic. According to the Guidelines for the diagnosis and management of cow's milk protein allergy in infants, these are the symptoms of CMPA in breastfed infants. Mild to Moderate Symptoms: Regurgitation, Vomiting, Diarrhea, Constipation, Rash, Blood in stool, Iron deficiency , Atopic dermatitis, Persistent distress, colic. Severe Symptoms: Failure to Thrive is included with the severe symptoms, which is when the child's weight or rate of weight gain is significantly below that of other children of similar age and sex. Severe symptoms: Diarrhea, Regurgitation, Vomiting, Refusal to feed, Severe atopic dermatitis, Protein-losing enteropathy , Moderate to large amounts of blood in stool.
  • Frequent regurgitation
  • Vomiting
  • Diarrhea
  • Constipation
  • Rash
  • Blood in stool
  • Iron deficiency anemia
  • Atopic dermatitis
  • Persistent distress or colic

Severe Symptoms in Breastfed Infants

The severe symptoms are similar to the mild to moderate, but also include “Failure to Thrive”. According to Hopkins Medicine, Failure to Thrive is when the child’s weight or rate of weight gain is significantly below that of other children of similar age and sex.

  • Diarrhea
  • Regurgitation
  • Vomiting
  • Refusal to feed
  • Moderate to large amounts of blood in stool
  • Protein-losing enteropathy (protein leaked from GI tract)
  • Severe atopic dermatitis

Mild to Moderate Symptoms in Formula-Fed Infants

CMPA (Cow's Milk Protein Allergy) symptoms informula-fed infants infographic. According to the Guidelines for the diagnosis and management of cow's milk protein allergy in infants, these are the symptoms of CMPA in formula-fed infants. Mild to Moderate Symptoms. Gastrointestinal: Frequent regurgitation, Vomiting, Diarrhea, Constipation, Rash, Blood in stool, Iron deficiency anemia. Dermatological: Atopic dermatitis, Angio-oedema, Urticaria (hives). Respiratory: Runny nose, Chronic cough, Wheezing. General: Persistent distress or colic. Persistent is described as wailing or irritable 3 or more hours a day, at least 3 days a week, for 3 or more weeks.

Gastrointestinal

  • Frequent regurgitation
  • Vomiting
  • Diarrhea
  • Constipation
  • Rash
  • Blood in stool
  • Iron deficiency anemia

Dermatological (skin)

  • Atopic dermatitis
  • Angio-oedema (swelling of lips or eyelids)
  • Urticaria (hives)

Respiratory

  • Runny nose
  • Chronic cough
  • Wheezing

General

Persistent distress or colic. Persistent is described as wailing or irritable 3 or more hours a day, at least 3 days a week, for 3 or more weeks.

Severe Symptoms in Formula-Fed Infants

Severe CMPA (Cow's Milk Protein Allergy) symptoms in formula-fed infants infographic. According to the Guidelines for the diagnosis and management of cow's milk protein allergy in infants, these are the symptoms of CMPA in formula-fed infants. Gastrointestinal: Chronic diarrhea, Chronic regurgitation, Chronic vomiting, Refusal to feed, Iron deficiency anemia, Protein-losing enteropathy, Enteropathy Severe ulcerative colitis. Dermatological: Exudative (wet) dermatitis, Severe atopic dermatitis, Low albumin levels. Respiratory: Acute laryngoedema , Bronchial obstruction. Systemic Reactions: Anaphylactic shock

The severe symptoms are similar to the mild to moderate, but also include “Failure to Thrive”. According to Hopkins Medicine, Failure to Thrive is when the child’s weight or rate of weight gain is significantly below that of other children of similar age and sex. 

Gastrointestinal

  • Chronic diarrhea
  • Chronic regurgitation
  • Chronic vomiting
  • Refusal to feed
  • Iron deficiency anemia
  • Protein-losing enteropathy
  • Enteropathy
  • Severe ulcerative colitis

Dermatological (skin)

  • Exudative (wet) dermatitis
  • Severe atopic dermatitis
  • Hypoalbuminaemia-anaemia (low albumin protein levels)

Respiratory

  • Acute laryngoedema (larynx swelling)
  • Bronchial obstruction

Systemic Reactions

  • Anaphylactic shock

If your child has or you suspect has CMPA, and they have any symptoms, take them to a doctor. If the symptoms are severe or seem life-threatening in any way, get emergency medical help right away.

CMPA Rash Images

These images are of children who have been diagnosed with atopic dermatitis. Atopic dermatitis is the most common skin rash that physicians see with CMPA.

Sleeping baby with a pacifier in mouth. The infant's checks are red, dry, and rash-like. Baby diagnosed with atopic dermatitis, possibly caused by cow's milk protein allergy (CMPA).
Photo Courtesy of Globalskinatlas.com
Infant with a yellow binky, with scaling red cheeks. baby was diagnosed with infantile atopic eczema, commonly seen in CMPA/CMA cases.
Photo Courtesy of Globalskinatlas.com
Image of a baby with red rash on both cheeks. The right cheek has a rash up to the baby's eye. This is an atopic dermatitis rash, with the possible cause of CMPA/CMA, cow's milk allergy.
Photo Courtesy of Globalskinatlas.com
Image of a baby's left cheek with excoriated dermatitis. Possible cause of rash on face is CMPA.
Photo Courtesy of Globalskinatlas.com
Image of a baby boy with red and scaly cheeks. Possible CMPA, cow's milk protein allergy.
Photo Courtesy of Globalskinatlas.com
infant with really red left cheek. atopic eczema rash spreading to behind the ear. possible cause is CMA.
Photo Courtesy of Globalskinatlas.com

How is CMPA diagnosed?

If you suspect your child has CMPA, the first step is to schedule an appointment with your pediatrician. They will likely refer you to an allergist for further testing. There are two main types of tests used to diagnose CMPA: skin tests, and blood tests.

Skin Test

The skin prick test (SPT) involves placing a drop of cow’s milk protein extract on the skin and then making a small puncture in the skin (usually the back or forearm) so that the allergen can enter. If your child is allergic, they will typically develop a wheal (a raised, itchy bump) within 15 – 20 minutes.

Blood Test

Blood tests are also used to diagnose CMPA. These tests measure the levels of Immunoglobulin E or IgE antibodies in the bloodstream. These antibodies or immune system cells are responsible for allergic reactions. High levels of IgE may indicate an allergy. 

CMPA Baby Formula

Once diagnosed with CMPA, your child’s Pediatrician may want to switch baby formulas. Read the CMPA Formula Guide next to gain a better understanding of the different types of formulas available.

By Chris

Chris is the creator of Allergy Preventions. As an allergy sufferer himself, his vision is to help others find relief from allergies. By combining his 14 years of Public Health experience, personal experience, and his thirst for knowledge, he is dedicated to providing quality recommendations to assist families with allergy symptom relief.