Single Dose Level Intradermal Skin Tests are not Diagnostic in Food Intolerance: A Double Blind Study

A double blind study was performed on 13 patients with food intolerance, confirmed by elimination dieting and repeated challenge. Intradermal testing was performed at 1:500, using 10 commonly reacting foods and 10 which rarely gave reactions, a total of 260 tests. As compared with the results of challenge, intradermal skin tests were assessed as 57.5% accurate. The results are compared with other studies, and whilst single strength intradermal testing cannot be put forward as a valid test for food intolerance it is suggested that apparent “false positive” responses may be due to a mechanism akin to atopy in IgE allergy.