Increased intestinal sugar permeability after challenge in children with cow's milk allergy or intolerance

The diagnosis of cow's milk allergy or intolerance (CMAI) is based on clinical improvement on exclusion diet and relapse after challenge with milk. The aim of this work was to investigate the value of the cellobiose/mannitol (C/M) sugar permeability test, performed before and after cow's milk challenge, as a tool for the diagnosis of CMAI. Thirty-two patients underwent milk challenge at a median age of 13 months (range 3–84 months). A dual sugar (C/M) permeability test with an iso-osmolar solution was performed before and 24 h after challenge. Of the 10 patients who developed symptoms after challenge, nine showed increased postchallenge C/M ratio, whereas such an increase was observed in only one of the 22 nonrelapsed subjects. The postchallenge C/M ratio increase in relapsed subjects is to be attributed to both higher cellobiose and lower mannitol urinary excretion. These results suggest the use of the sugar permeability test, in addition to clinical observation, as an aid in the evaluation of provocation tests in infants with suspected CMAI.