Intestinal biopsy in the diagnosis of cow's milk protein intolerance without acute symptoms

4 infants, suspected of cow's milk protein intolerance, were placed on an elimination diet and then challenged with cow's milk. None reacted clinically, yet in 2 of the 4 patients jejunal biopsy revealed clear histological, ultrastructural, and immunological changes. It is suggested that these changes are the objective criteria on which the diagnosis of cow's milk intolerance should be based, and that the clinical evidence derived from milk challenge after an elimination diet may be unreliable.