Cow milk protein allergy mimics in infancy

Table 1 Differentiation between IgE-mediated and non-IgE-mediated cow milk protein allergy

Feature	IgE-mediated CMPA	Non-IgE-mediated CMPA
Mechanism of allergy	Allergic reactions mediated by IgE antibodies binding to allergens, mast cells, and basophils, triggering mast cell degranulation and histamine release	T-cell mediated immune response leading to inflammation without IgE involvement
Pathophysiology	Immune response involving IgE antibodies	Immune response without IgE involvement
Onset of symptoms	Rapid onset, usually within minutes to hours after ingesting cow’s milk protein	Delayed onset, typically hours to days after ingestion
Common presentation age	It is more common after initial exposure to cow’s milk protein through formula or food introduction	It often occurs early in infancy, even in exclusively formula-fed infants
Symptoms	Urticaria, angioedema, anaphylaxis; Respiratory symptoms (wheezing, nasal congestion); Immediate gastrointestinal symptoms (vomiting)	Chronic diarrhea, constipation, blood-streaked stools; Gastroesophageal reflux-like symptoms; Poor feeding, colic, and failure to thrive
Systemic involvement	Systemic reactions, including anaphylaxis, are common	Limited to localized inflammation, primarily in the gastrointestinal tract
Severity	It can be life-threatening (e.g., anaphylaxis)	Symptoms are generally less acute but may lead to chronic complications
Duration of symptoms	Symptoms resolve quickly once exposure ceases	Symptoms persist until the trigger is eliminated for an extended period
Diagnostic tools	Skin prick test; Serum-specific IgE testing; Food challenge (confirmation)	Diagnosis of exclusion; Elimination diet and reintroduction challenge; No reliable specific tests available
Management	Strict avoidance of cow’s milk protein and use of emergency medication (e.g., epinephrine for anaphylaxis)	Strict avoidance of cow’s milk protein, ensuring nutritional adequacy of alternatives
Resolution	It may persist longer, though some children outgrow it by school age	Often resolves by 1-3 years of age

This table shows the underlying mechanisms of allergy, providing a more comprehensive comparison of IgE-mediated and non-IgE-mediated cow milk protein allergy. CMPA: Cow milk protein allergy.