INFLUENCE OF VARYING PHYSICAL FACTORS ON PATCH TEST RESPONSES

[摘要] In the performance of patch tests with solid materials, pressure upon a hard substance can produce a false reaction. This is almost invariably marginal at the site of an edge. However, if the test substance has enough height and enough pressure exerted upon it, the reaction can be of a diffuse nature covering the entire patch test area. An elastic substance, such as sponge rubber, if thick enough, and sufficiently compressed can produce a non-specific traumatic effect. Sponge rubber of less than 5 mm thickness will not produce this non-specific marginal effect. In performing patch tests with hard substances, one should bear in mind the possibility of these non-specific reactions. Pressure can potentiate a patch test with an allergen, particularly at higher dilutions or in instances of a low degree of sensitivity.