ORAL DIAGNOSTIC CHALLENGES

Abstract

Over 2000 years ago in ancient Greece, Hippocrates (460–375/351 bc) recorded his observations of an adverse food reaction (i.e., milk-induced),18 and in his treatise on ancient medicine, admonished patients to “search out food befitting their nature.”7 Writings from Galen, physician and philosopher (130–200 ad), indicate that the Romans were also well aware that foods safely consumed by most of the population could not be tolerated by some and could initiate many forms of adverse reactions.16 Centuries later, in 1921, Carl Prausnitz and Heinz Kustner, in a significant breakthrough contribution, demonstrated the passive transfer (P-K) test. By injecting his own serum into Prausnitz, who had a known sensitivity to fish, Kustner was able to provoke a wheal and flare response at the injection site following fish ingestion by Prausnitz.17 Although now used only for special purposes because of the risk of transmitting AIDS and other diseases, the test succeeded in establishing substances in blood serum as the causative factor in food allergy. Blinded, placebo-controlled food trials were introduced in 1950 by Loveless who incorporated “food masking” techniques to disguise a suspected food in a safe food, thereby avoiding detection by the patient.10, 11 At that same symposium, Graham et al presented a paper examining the placebo effect. Patients in this study reacted more to what they believed was being administered than to the actual food, showing once again the human mind's ability to conjure up and to remand symptoms.5, 15 Further pioneering work by May, in 1976, used the double-blind, placebo-controlled food challenge (DBPCFC),14 a procedure that continues to be recognized as the standard in diagnosing food allergy.18