Clinical Evaluation of Moisturizers with Physiological Analysis of Stratum Corneum TARC and TSLP

To verify the usefulness of moisturizers, a multi-center study was conducted on patients with atopic dermatitis who visited 3 university hospitals in Japan between November 2009 and March 2012. Thirty-seven patients with dry skin and stable symptoms who were receiving topical and oral treatments were given moisturizers for 8 weeks. The moisturizers contained components such as glycerin and seawater minerals in 3 forms: lotion, emulsion, and cream. The moisturizers were chosen by physicians based on the degree of dryness of the patients’ skin. In addition to observing the skin condition of the entire body, high-frequency conductance as a parameter of skin surface hydration and transepidermal water loss (TEWL) in the buccal region and the medial side of the forearm were measured, and those of the back were used for comparison. Furthermore, stratum corneum levels of thymic stromal lymphopoietin (TSLP) and thymus and activation-regulated chemokine (TARC), both of which were objective parameters for atopic dermatitis skin lesion severity, were analyzed using the tape stripping method. At the beginning of the study, TSLP showed a correlation with skin symptoms (dryness, itching) and high-frequency conductance, whereas TARC showed a correlation with skin symptoms (erythema, dryness, itching) and TEWL. In addition, a correlation was noted among TSLP, TARC, and itching. At the end of the study, erythema, dryness, itching, TEWL,TSLP, and TARC were significantly reduced, whereas high-frequency conductance was significantly increased. The moisturizers clearly improved the dry skin symptoms of these patients with atopic dermatitis and improved the physiology of their sensitive and damaged skin. These findings also support the involvement of cytokines/chemokines in the pathogenesis of atopic dermatitis lesions.