Regeneration of the epidermal barrier in irritant hand eczema: in vivo evaluation of the efficacy of a therapeutic basic preparation

Background: Therapeutic basic preparations are used to restore barrier function in irritant hand eczema. The efficacy of a hand cream on parameters of skin barrier regeneration was investigated in a human in vivo evaluation model.Material and methods: Observer-blinded randomized controlled trial in 20 subjects in a cumulative irritation model. After irritation of the skin with sodium lauryl sulphate 0.5% twice a day for 4 days, the irritated test area was treated with the test product. A second, irritated, untreated test area and a third, neither irritated nor treated test area were used as controls. The test areas were evaluated clinically and with non-invasive technical methods (TEWL measurement, corneom-etry, and chromametry) over 5 examination days.Results: On day 5, there was a signifi-cant increase in the visually recorded signs of inflammation (p = 0.0144) and TEWL (p = 0.0323) in the irritated untreated test area compared to the treated test area. Corre-spondingly, on day 5, the treated test area showed significantly (p = 0.0119) less red-ness as determined by chromametry com-pared to the non-treated irritated test area. Skin hydration was significantly higher on day 5 in the treated area compared to the irritated non-treated test area (p = 0.0007).Conclusion: Significant positive effects on the clinical and skin physiological parameters of barrier function and inflammation relevant for the regeneration of the skin bar-rier were observed in the treated test area after experimental irritation. Thus, the eval-uation model can be used to demonstrate the efficacy of the formulation on the regen-eration of the skin barrier after irritation.