Diagnostic Usefulness of the Serum-Specific IgE, the Skin Prick Test and the Atopy Patch Test Compared with That of the Oral Food Challenge Test.

BACKGROUND Atopic dermatitis (AD) is frequently associated with food allergies. In addition to the skin prick test (SPT) and serum-specific IgE, the atopy patch test (APT) has been introduced as a diagnostic procedure for food allergies. OBJECTIVE Our aim was to evaluate the diagnostic value of the APT, the SPT and the serum-specific IgE levels compared with that of oral food challenge test against milk and egg in AD patients. METHODS We conducted the SPT and APT, and determined the serum-specific IgE levels against milk and egg antigens for 101 patients. Oral food challenge tests were conducted for 86 out of 101 AD patients. The sensitivity, specificity and positive and negative predictable values were calculated for all the tests. RESULTS Twenty-five patients were positive to oral food challenges. The sensitivity of the APT for milk was 66.7%, while the figures for the SPT and the serum-specific IgE were 35.5% and 14.2%. The sensitivity of the APT for egg was 50%, while that for the SPT and serum-specific IgE were 21.4% and 6.7%. CONCLUSION We were able to conclude that the APT test seems to be a valuable additional tool for the diagnostic method of food allergies in AD.