Food-induced alterations of intestinal permeability in children with cow's milk-sensitive enteropathy and atopic dermatitis.

Intestinal permeability was evaluated by measuring the excretion of two orally absorbed (0.1 g/kg of weight) nonmetabolizable markers, mannitol and lactulose. In 39 controls, the lactulose/mannitol urinary ratio (L/M ratio) was 2.45 +/- 1.01% during fasting and remained stable after food ingestion. In 12 children with cow's milk-sensitive enteropathy under an exclusion diet, the L/M ratio was comparable with that of controls during fasting and exhibited a threefold rise during a provocation intestinal permeability test (IPT) with milk. In 28 children with atopic dermatitis (AD), the fasting IPT L/M ratio was significantly higher than in controls (3.60 +/- 3.31%). This rise was related to an increase of lactulose urinary clearance. A provocation IPT with food induced significant L/M ratio changes only in the group in which the food was proved to be responsible for the exacerbation of skin lesions. We concluded that in cow's milk-sensitive enteropathy, an IPT allows a good evaluation of mucosal reactivity to milk, and in AD, permeability changes are present in at least some cases with cutaneous lesions clearly related to food ingestion.