Cows' milk protein intolerance: a possible association with gastroenteritis, lactose intolerance, and IgA deficiency.

Twenty-five children with cows' milk protein intolerance were studied. Twenty had presented with an illness clinically indistinguishable from infantile gastroenteritis; an enteropathogenic Escherichia coli was isolated from the stools in two children, and in six another member of the family simultaneously developed acute diarrhoea and vomiting. Twenty-three children had lactose intolerance secondary to cows' milk protein intolerance. Eight out of 20 children were found to be partially IgA deficient. An acute attack of gastroenteritis, in damaging the small mucosa, may act as a triggering mechanism in cows' milk protein intolerance, and a deficiency in IgA may be a predisposing factor in so far as it allows the patient to become sensitised to foreign protein.