IRRITANT PATCH TESTING WITH SODIUM LAURYL SULFATE - A RELIABLE, NONINVASIVE TOOL PREDICTING SKIN SUSCEPTIBILITY

The purpose of this study was to determine whether 24 hour patch testi ng with 0.5% sodium lauryl sulphate (SLS) could reliably predict skin susceptibility to an irritant when compared with the alkali resistance test (ART), a widely used method employing sodium hydroxide. After ha ving given informed consent, 40 patients (age range from 20 to 60 year s) with an active Irritant contact dermatitis (ICD), 40 patients in wh om ICD had cleared, as well as 40 healthy volunteers serving as contro ls were tested. The skin responses to SLS were assessed both visually and by measurement of transepidermal water loss (TEWL) as an Indicator of stratum corneum integrity. SLS significantly increased the erythem a scores and TEWL in patients with healed ICD, and the increase of TEW L was even more pronounced in patients with active ICD. By contrast, a decrease in alkali resistance was found in patients with active ICD o nly but not in patients with healed ICD. The data obtained indicate th at the SLS test, unlike ART, may provide a non-invasive tool predictin g a possible constitutional skin susceptibility or indicating a subcli nically impaired epidermal barrier function. However, because of the r elatively high interindividual variation, a cut-clear statement concer ning the skin susceptibility cannot be made by this test. On the other hand, the ART seems only to be useful for following and documenting t he healing period following ICD.