Reaginic hypersensitivity to cow's milk proteins.

Seven cases of infants presenting an anaphylactic reaction at their first cow's milk or formula feeding after a period of exclusive breast feeding are reported. Laboratory data are consistent in all cases with an IgE-mediated pathogenetic mechanism. All infants received cow's milk at nursery. The importance of avoiding this practice, by the nursery teams is emphasized, and the unusual close correspondence of clinical and laboratory data is discussed.