[Allergy to cow's milk proteins: the sensitivity of specific and nonspecific laboratory tests]

Authors report their experience of a population of 308 children affected by cow's milk allergy who presented gastrointestinal, respiratory and cutaneous symptoms. Diagnosis was based on challenge with cow's milk proteins and on laboratory specific tests (RAST, prick test) and non specific ones (PRIST, eosinophil count, 1-h xylose test, occult blood in the stools), following ESPGAN criteria. The patients were subdivided in 3 groups: a) patients with prevalent gastrointestinal symptoms; b) patients with prevalent cutaneous symptoms and c) patients with both, gastrointestinal and cutaneous symptoms. The sensitivity of the employed tests was evaluated either in the whole patient population or in the there group according to symptoms. Our data show a high sensitivity of the RAST for cow's milk (70%) versus a lower sensitivity of prick test (53%) when the whole patients population was considered. Moreover statistically important differences of the sensitivity of the various tests were found when the three groups of patients were considered, as well as when such a comparison was done in patients subdivided according to age (more or less than 6 months). Finally the concord between RAST and prick test was evaluated in the three groups.