[Positive strip patch test reactions with coexistent negative patch test reactions. Relevance for the assessment practice of occupational skin disease].

The strip patch test is recommended whenever a patch test is presumed to be false negative. The aim of this technique is to increase skin sensitivity to test substances by removing the upper layers of the stratum corneum prior to patch testing. We report on a 57-year-old former heavy-current electrical worker, who suffered from hyperkeratotic fissured hand eczema. Sensitization to nickel sulphate was demonstrated in both 2001 and 2009 with strip patch testing even though conventional patch testing was negative. To our knowledge, this is the first description of an allergy to nickel with a pension entitlement according to no. 5101 of the German ordinance on industrial disease based solely on positive strip patch tests.