The effect of wet-wrap dressing on epidermal barrier in patients with atopic dermatitis

Background: Wet-wrap dressing has been shown to be effective for atopic dermatitis; however, the therapeutic mechanism of wet-wrap dressing is only the hypothesis based on the recovery of decreased epidermal barrier function. Objectives: To examine the therapeutic efficacy as well as the mechanism of wet-wrap dressing in atopic dermatitis patients. Methods: To examine the difference of non-lesional and lesional atopic skin and to evaluate the change between epidermal barrier function before and after the treatment, SCORAD, epidermal water content, transepidermal water loss, the lipid amount of skin surface, immunohistochemical staining of filaggrin and loricrin, transmission electron microscopic examination, and calcium ion capture cytochemistry method were done in 10 severe form atopic dermatitis patients. Results: In atopic dermatitis patients, SCORAD was clearly decreased, epidermal water content was increased, and transepidermal water loss was decreased after wet-wrap dressing. After wet-wrap dressing, increased release of lamellar body and the recovery of the damaged lamellar structure of intercellular lipid were observed; nevertheless, neither the change in keratinocyte differentiation nor the change of calcium ion gradient was detected. A week after the termination of wet-wrap dressing, increased water content and decreased transepidermal water loss were still maintained. Conclusion: We confirmed the abnormality of the epidermal barrier in atopic dermatitis, and the effects of wet-wrap were associated with the recovery of epidermal barrier. In atopic lesions, wet-wrap dressing induced clinical improvement by the release of lamellar body and the restoration of intercellular lipid lamellar structure.