An Open Single Centre Evaluation of the Reactivity of the T.R.U.E. Test Quaternium-15 Patch and a Real Use Exposure in Subjects Known to Be Allergic to Quaternium-15

The study is required by the FDA as part of a post-marketing commitment. The purpose of the study is to compare the reactivity of the TRUE Test quaternium-15 patch and a real use exposure.The subjects will wear the patch test for 48 hours and reading will be performed day 3 or 4. The use test will be applied from day 3 or 4 and untill reaction appears. Reactions from respectively TRUE Test and use test will be compared using the McNemar Change Test.