Challenges for the future of patch testing

Abstract

The importance of patch testing was highlighted by the comments of Dr. Marion Sulzberger, who was asked the five most important advances in clinical dermatology during the twentieth century. He listed as the first advance the increased use and usefulness of the patch test and the international standardization of test concentrations and methods. The other four advances that Sulzberger listed were the use of systemic corticosteroids, the use of topical corticosteroids, immunofluorescent techniques, and our increased knowledge of the role of the Langerhans cellin allergic contact dermatitis and homograft resistance to cancer.1 It should be noted that Sulzberger listed patch tests as the first of the most important advances in clinical dermatology. Obviously, such a clinically important diagnostic procedure should not be withheld because certain rare and mostly minor adverse reactions may occur. A major abuse of patch testing is its omission in the diagnosis and management of allergic contact dermatitis. In discussing the hazards of patch tests, Snyder and Maibach 2 state: Patch testing, like many diagnostic methods, is not without hazard. The risk is greatly decreased by expertise with the method. In any instance, the risk of not identifying the allergen is greater than that of performing such testing. Likewise it is a challenge to prevent abuse of the patch test for medical diagnosis. One such abuse is easily seen in the actions of a Florida company that marketed a mercury chloride patch test kit. This product was sold to dentists with instructions to apply the patch and monitor the patient's pulse and blood pressure. It was recommended that ff the pulse and blood pressure rose, any dental fillings containhag mercury were to be removed and replaced with gold fillings. The U.S. Food and Drug Administration had to intervene in this abuse. 3 Another abuse promoted to allergists involved the use of dimethylsulfoxide (DMSO) as an agent for