Influence of patch-test application tape on reactions to sodium dodecyl sulfate

There remains much room for improvement in the accuracy of the patch test p rocedure. There has been a lack of knowledge regarding the possible relatio nship between the intensity of test reactions and the quality of the tape u sed to apply patch tests. Using different brands of tape, patches coated wi th 2 mg/cm(2) sodium dodecyl sulfate (SLS) were applied for 24 h to the bac ks of 10 volunteers. The tape specimens varied in terms of manufacture, ela sticity, adhesive strength, and water permeability. The intensity of patch test reactions, evaluated visually and objectively with both the high resol ution laser Doppler perfusion imaging technique (HR-LDPI) and transepiderma l water loss measurements (TEWL), varied significantly with the different b rands of tape. Observed variations in the intensity of reactions to the pat ch tests could not be explained by any of the 4 tape parameters investigate d. In order to attain optimal test quality in the future, both the tape and patches used in the testing system should be standardized and clearly labe lled.