Importance of the first meal on the development of cow's milk allergy and intolerance.

A cohort of 1749 newborns from the municipality of Odense born during 1985 in the University Hospital of Odense were followed prospectively for the development of cow's milk allergy (CMA)/cow's milk protein intolerance (CMI) during their first year. The diagnosis of CMA/CMI was based on elimination/open milk challenge procedures according to generally accepted criteria. Thirty nine infants (2.2%) developed CMA/CMI. Infants with CMA/CMI were fed cow's milk formula daily during the first month of life significantly more often than infants in the study population (p less than .001). All 39 infants with CMA/CMI had ingested cow's milk formula (40-830 mL) neonatally, whereas none of the 210 neonates without supplements of cow's milk formula developed CMA/CMI (p less than .05). Based on a positive skin-prick test (2+ or more) and/or specific serum IgE antibody to cow's milk (AL-RAST class 2 or more) 16 infants were classified as having CMA. In infants solely breast-fed for greater than 1 month CMA was as frequent (1% [14/1414] as in cow's milk formula fed infant (0.6% [2/335]). In infants with CMI, a significant majority (3.9% [13/335] versus 0.7% [10/1414], p less than .001) had been cow's milk formula fed during the first month. These data indicate an association between early cow's milk formula feeding and development of reproducible adverse reactions to cow's milk protein. Early neonatal intake of cow's milk protein is probably a condition of sensitization and later adverse reactions to cow's milk protein.