Assessment of patch-test reactions to so-called "problem allergens" in cases of occupational skin disease [Bewertung von epikutantestreaktionen auf "problemallergene" mit vermehrt fraglichen oder schwach positiven reaktionen]

Abstract

Ideally, a patch-test preparation should elicit a positive test reaction in a sensitized individual and a negative test reaction in a non-sensitized individual. Almost every contact allergen also irritates the skin, thus leading to doubtful, irritant or false-positive test reactions. Some patch-test preparations may be called "problem allergens" because they are particularly prone to elicit doubtful and weak positive test reactions. This complicates the interpretation of patch-test reactions (allergic versus non-allergic or irritant). Any patch-test reaction to so-called "problem allergens", which are listed in this publication, requires an in-depth medical history or - if possible - an exposure analysis to assess clinical relevance individually. Patch testing with an irritant control (SLS 0.25% AQU) helps interpreting doubtful and weak positive patch-test reactions. © 2010 Dustri-Verlag Dr. Karl Feistle.