The strip patch test--indication in occupational dermatology demonstrated with a case history.

In occupational dermatology, repeat patch testing is a frequent occurrence when an expert opinion is required. As a result, discrepancies in test results may affect the legal position in respect of insurance and a reduction in the level of disability. The strip patch test (SPT) supports the diagnosis of allergic contact dermatitis when a weak sensitization is present or when a weak sensitizer with poor epidermal penetration is involved leading to a false-negative patch test result. We report on a 30-year-old man working as an industrial mechanic from 1995 to 2006. After approval of an occupational disease no. 5101 of the German ordinance on industrial disease in 2007, he went to court claiming compensation. The sensitization with clinical and occupational relevance to potassium dichromate that was decisive for the evaluation for insurance purposes was first confirmed in a patch test in 2005. Succeeding tests in 2006 in the context of an expert opinion and in 2008 in the context of our decisive expert opinion remained negative. We could reconfirm the potassium dichromate sensitization only by the SPT performed in the proposed standardized manner. The potassium dichromate allergy was the determining factor in the assessment for insurance purposes. This resulted in an adjustment in the severity of disability and a pension entitlement. From this case it is obvious that the detection of a SPT-positive and patch test-negative sensitization may have a significant impact on the situation with respect to the legal and insurance position.