CMPA, or Cow's Milk Protein Allergy, is an immune response to proteins found in dairy products like casein and whey. This condition typically occurs when an infant or young child consumes or comes into contact with cow's milk.
Commonly known as a milk allergy, CMPA can trigger symptoms immediately or several days after exposure to dairy proteins. Typical reactions range from skin hives and vomiting to more chronic issues like diarrhea or delayed physical growth.
While CMPA most often affects infants and children due to their developing immune systems, it can occasionally persist into adulthood. Doctors usually diagnose the condition through clinical evaluations, elimination diets, or specific allergy testing.
Main symptoms
Symptoms of CMPA vary based on how the immune system reacts to the protein. These signs can appear within minutes of consumption or may take up to a week to manifest after contact with cow's milk.
1. Immediate reaction symptoms
Immediate reactions usually occur within minutes and generally no later than two hours after ingestion or skin contact. Common signs include:
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Skin redness, inflammation, and itching
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Nausea and vomiting
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Diarrhea
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Abdominal pain
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Coughing or wheezing
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Runny or congested nose
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Itchy, watery eyes
In severe cases, a person may experience difficulty breathing, shortness of breath, or throat swelling. This is known as anaphylactic shock and requires emergency medical intervention.
2. Delayed reaction symptoms
Delayed reactions can take hours or even several days to appear after exposure to cow's milk. These symptoms often include:
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Blood in the stool
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Acid reflux
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Constipation
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Esophageal inflammation
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Anemia
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Intestinal or lung inflammation
Parents may also notice increased irritability, a lack of appetite, or a noticeable slowdown in the child’s growth rate during delayed reactions.
Confirming a diagnosis
A pediatrician or general practitioner typically diagnoses CMPA by evaluating the symptoms that occur after a child consumes dairy products.
The physician may order blood tests or a skin prick test. During a skin prick test, tiny amounts of potential allergens are placed on the skin to check for a physical reaction.
Doctors also use elimination diets, where specific foods are removed to see if symptoms improve. This helps pinpoint exactly which food is triggering the allergic response.
If symptoms resolve after removing milk, the doctor might perform an oral food challenge. This involves feeding the child small, controlled amounts of milk in a hospital setting to monitor for reactions safely.
Treatment options
Managing CMPA involves strictly removing cow’s milk and dairy products such as cheese, butter, ice cream, and certain baked goods from the diet. For infants, a pediatrician will recommend specialized hypoallergenic formulas that do not contain cow's milk protein.
To prevent nutritional gaps, a doctor may suggest supplements. These help avoid deficiencies that lead to conditions like scurvy (lack of vitamin C) or certain types of nutritional deficiencies caused by a lack of B vitamins.
Can a baby be allergic to breast milk?
While it is uncommon, an exclusively breastfed infant can still react to cow's milk protein. This happens when proteins from the dairy products the mother eats pass into her breast milk. In these instances, the mother is usually advised to follow a dairy-free diet herself.
Difference between lactose intolerance and CMPA
Lactose intolerance is a digestive issue where the body lacks lactase, the enzyme needed to break down lactose (milk sugar). This typically causes localized digestive issues like gas, bloating, and diarrhea.
CMPA is an immune system response. In addition to digestive problems, it causes systemic allergy symptoms like hives, nasal congestion, and respiratory distress. Serious cases can lead to anaphylactic shock, which does not occur with simple lactose intolerance.