855 Double Blind Placebo Controlled Food Challenge Useful to Disconfirm Over Estimated Diagnosis of Cmpa in Children

Background and aims: The incidence of CMPA in infancy seems to be approximately 3%. In Italy diagnosis of CMPA is often over estimated. The double-blind, placebo controlled food challenge(DBPCFC) is widely considered as the “gold standard” for the diagnosis of food allergy. Methods: 14 patients, (12 months-12 yrs) previously diagnosed as having CMPA, underwent our diagnostic algorithm in order to confirm or to exclude diagnosis. Diagnostic algorithm includes: total blood cell count, serum IgE assay, RAST, betalactotest, Prick by prick with fresh milk, chemical examination and eosinophilic cell count of the stools. DBPCFC was performed with extensively hydrolyzed formula (as placebo) VS a lactose-free, cow milk derived formula. At discharge a post challenge form was given to parents to record delayed symptoms that might occur at home. Results: 12 out of 14 patients had positive results for skin prick test (prick by prick) and four out of them also presented specific IgE against CMPs. 13 patients showed tolerance to CMP during and after DBPCFC and had no symptoms also in the next 72h. Only one patient, aged 30 months, had to keep CMP avoidance. Conclusion: In our survey DBPCFC demonstrated tolerance to CMP for all but one patients. DBPCFC is effective also to disconfirm diagnosis of CMPA. Skin prick tests and serological specific IgE do not always correlate with oral tolerance test. Subjects with positive skin prick test and high serological specific IgE against CMP but tolerant at DBPCFC may reintroduce cow milk proteins in to their dietary meals.