RELATIONSHIP BETWEEN ORAL CHALLENGES WITH PREVIOUSLY UNINGESTED EGG AND EGG-SPECIFIC IGE ANTIBODIES AND SKIN PRICK TESTS IN INFANTS WITH FOOD ALLERGY

Background: Positive skin prick test (SPT) and RAST reactions to egg t hat had never previously been ingested have been observed in infants w ith food allergy. The likelihood of having clinical hypersensitivity r eactions when egg is first ingested and the predictive value of SPT an d PAST remain to be elucidated. Objective: We investigated the relatio nship between egg-specific IgE antibodies and positive SPT reaction to egg, and the development of clinical hypersensitivity on the first ex posure, in infants with food allergy. Methods: The patient group consi sted of 21 infants with food allergy and positive SPT and/or RAST reac tion to egg, which they had never previously ingested; the control gro up of 12 infants had food allergy and negative test results. All subje cts underwent double-blind placebo-controlled food challenges with egg . Results: Thirteen of 21 patients (61%) and one of 12 control subject s (8%) had positive reactions to challenges (p < 0.01). Thirteen posit ive reactions to challenges (93%) elicited immediate symptoms. Late-on set eczema occurred in two children. SPT results showed a high sensiti vity (0.92) and negative predictive accuracy (0.92), whereas specifici ty (0.57) and positive predictive accuracy (0.61) were poor. RAST did nor have any diagnostic advantage over SPT. Conclusions: In infants wi th food allergy SPT with egg may be helpful in predicting which patien ts will react to the first exposure.