The prick test and specific IgE (RAST and MAST-CLA) compared with the oral challenge test with milk, eggs and nuts.

In spite of the development of numerous in vivo and in vitro diagnostic techniques for food allergy, the oral challenge test (OCT) is still the "gold standard". Consequently, we have compared it with some of the more recent techniques. We studied 36 patients with a medical history compatible with food allergy (to milk, eggs or nuts) and 11 patients without food allergy (6 nonatopic and 5 with acarid allergy). A prick test, specific IgE (RAST and MAST-CLA) and an OCT with the suspected food were performed in all patients. The following parameters were calculated for all patients overall and for each of the three allergic groups separately: sensitivity, specificity and match with the OCT. We also studied the RAST-MAST-CLA correlation and the variability of the MAST-CLA. The prick test was the most sensitive (95%) and the MAST-CLA (13% divergence in two measurements) the most specific (92%). The RAST and the MAST-CLA (68% match) gave similar results, with an acceptable match (75% and 77%, respectively) with the OCT. The medical history could only suggest the diagnosis (39% false-positives). After comparing the results with those in the literature, it is suggested that greater attention should be paid to the limitations of these techniques compared with the OCT.