CMPA

Cow milk protein allergy (CMPA) is an immune-mediated adverse reaction to proteins found in cow’s milk. It is one of the most common food allergies in infancy and can be IgE-mediated, non-IgE-mediated, or mixed. The condition presents with a broad range of symptoms affecting the skin, gastrointestinal tract, and respiratory system, and the specific pattern depends on the immune mechanism involved.

IgE-mediated CMPA typically causes rapid symptoms within minutes to hours after exposure, such as urticaria or angioedema, coughing or wheeze, and, in rare cases, anaphylaxis. Non-IgE-mediated CMPA often presents with delayed gastrointestinal symptoms including vomiting, diarrhea, poor weight gain, or blood-streaked stools over hours to days. Some children have mixed forms with both immediate and delayed manifestations. Atopic dermatitis may accompany CMPA, especially in infancy.

Diagnosis relies on clinical history and response to elimination and reintroduction of cow’s milk proteins. Skin prick testing and serum-specific IgE testing can support suspected IgE-mediated CMPA but are not definitive for non-IgE CMPA. The gold standard for diagnosis is a supervised oral food challenge to cow’s milk, typically conducted after an initial elimination period. In some cases, especially with complicated or persistent symptoms, referral to an allergy specialist is recommended.

Management centers on eliminating cow’s milk protein from the diet, tailored to the patient’s age and feeding method. Breastfed infants may require the mother to avoid dairy; formula-fed infants usually use extensively hydrolyzed formulas or amino acid-based formulas if intolerance to hydrolyzed formulas occurs. Most children outgrow CMPA, with many achieving tolerance by early childhood, though some have lifelong allergy. Regular follow-up ensures nutritional adequacy and monitors potential progression to tolerance.