In vivo assessment of cytological changes by means of reflectance confocal microscopy – demonstration of the effect of topical vitamin E on skin irritation caused by sodium lauryl sulfate

Background: Irritant contact dermatitis is caused by skin barrier damage. Vitamin E is an antioxidant that is commonly used in cosmetics to prevent photo-damage. Objectives: To show the usefulness of reflectance confocal microscopy in the assessment of irritant skin damage caused by sodium lauryl sulfate (SLS) and of the protective action of vitamin E applied prior to skin irritation. Patients/materials/methods: Ten healthy volunteers were enrolled. Irritation was induced by the application of a patch test containing SLS 5% aq. for 24h. Three sites were compared: one site on which a product with vitamin E was applied before SLS treatment, one site on which the same product was applied after SLS treatment, and one control site (SLS only). Each site was evaluated with reflectance confocal microscopy, providing invivo tissue images at nearly histological resolution. We also performed a computerized analysis of the VivaStack® images. Results: Reflectance confocal microscopy is able to identify signs of skin irritation and the preventive effect of vitamin E application. Conclusion: Reflectance confocal microscopy is useful in the objective assessment of irritative skin damage.