Milk protein allergy is a recognized problem in an infant's first year of life. Cow’s milk protein allergy is the most common such allergy and a common condition encountered in children with incidence estimated as 2% to 7.5% in the first year of life.1 Diagnosis is suspected on history alone, with laboratory evaluations playing a supporting role. Confirmation requires elimination and reintroduction of the suspected allergen. Management includes diet modification for nursing mothers and hydrolyzed formulas for formula-fed infants. Assessing the underlying immunopathology can aid in determining prognosis.