Rapid resolution of milk protein intolerance in infancy.

OBJECTIVES: Infants with milk protein intolerance are usually switched to a casein hydrolysate or amino acid-based formula, which they continue to receive until 1 year of age, when they are rechallenged with a cow's-milk or soy protein formula. To investigate whether some of these infants actually become tolerant sooner, this study gathered preliminary data for establishing an empirical timetable for the resolution of milk protein intolerance. METHODS: This prospective, longitudinal cohort study enrolled infants <4 months of age receiving either breast milk or a cow's-milk or casein hydrolysate formula who presented to a pediatric subspecialty practice during an 18-month period and had a positive stool guaiac test...