Severe cow's milk induced colitis in an exclusively breast-fed neonate. Case report and clinical review of cow's milk allergy.

Cow's milk induced eosinophilic colitis presenting in the first week of life has been reported, but is very rare. The authors describe a 4-day-old female infant who presented with profuse rectal bleeding resulting in a hematocrit fall from 38% to 30% within 8 hr after hospital admission. Sigmoidoscopy revealed colonic mucosa that was red, edematous, and friable, with punctate hemorrhages. Rectal biopsy showed marked eosinophilic infiltration with multifocal hemorrhage. Further history indicated that while the infant had been exclusively breast-fed since birth, the nursing mother had been drinking 4-5 glasses of cow's milk per day since delivery. Prick puncture skin testing of the infant was positive for cow's milk protein. A serum radioallergosorbent test (RAST) for cow's milk protein was positive. The infant's serum IgE was 1.5 IU/ml. Rectal bleeding resolved when the patient was given a casein hydrolysate formula (Nutramigen, Mead Johnson Nutrition, Evansville, IN), and endoscopy one week later showed improvement, with only scattered areas of erythema, and no friability. We conclude that since the infant was exclusively breast-fed, the milk protein must have passed into the breast milk antigenically intact. Prenatal sensitization probably occurred. Cow's milk induced allergic colitis should be considered in the differential diagnosis of colitis in breast-fed neonates.