The Skin Prick Test is Not Useful in the Diagnosis of the Immediate Type Food Allergy Tolerance Acquisition

BACKGROUND: Some studies have been reported about positioning of SPT in the diagnosis of food allergy. On the other hand, it is not yet clear about the positioning of SPT in the diagnosis of tolerance acquisition of the immediate type food allergy. METHODS: The retrospective study had been conducted for 236 egg allergic children (51.3 months in mean), 127 milk allergic children (53.4 months), and 96 wheat allergic children (42.6 months). The retrospective analysis of serum nonspecific and antigen-specific IgE levels, SPT, and OFC had been conducted for each allergic patient. All OFC had been conducted to verify the acquisition of tolerance against eliminated food. RESULTS: The OFC was positive in 61 (25.8%) hen's egg allergies, 34 (26.8%) milk allergies and 33 (34.4%) wheat allergies. The greatest AUC for each allergen is as following; hen's egg for egg white specific IgE at 0.745, milk/histamine (wheal) index at 0.718, and wheat for wheal size at 0.597. For the predictive decision points, the highest accuracy rate was at 25.8% for an egg white wheal of 9.5mm, at 26.8% for a milk wheal of 9.5mm, and at 34.4% for a wheal of 6.5mm. CONCLUSIONS: As a result of this analysis, the diagnostic accuracy of SPT had not been satisfactory to judge the acquisition of tolerance in allergic children for eggs, milk and wheat. Therefore, this is not a strong evidence to testify the tolerance of the immediate type food allergy.