Clinical Efficacy of Topical Ziyun Ointment in Improving Skin Hydration and Reducing Transepidermal Water Loss in Psoriasis

Ziyun Ointment, a traditional Chinese herbal remedy, is often applied externally; however, its physiological effects on the skin have not been thoroughly studied. This study aimed to assess the skin parameters of psoriasis patients before and after 12 weeks of Ziyun Ointment application. Methods: 30 participants were recruited and classified into mild, moderate, and severe. The pre-test and post-test measurements of skin parameters, including melanin and erythema index, stratum corneum lipids, stratum corneum hydration, and transepidermal water loss (TEWL), were conducted using the non-invasive Cutometer Dual MPA580. Result: 80% of the patients improved PASI, and the PASI score was significantly reduced by 2.58 ± 1.35 (p < 0.05). After continuous use of Ziyun Ointment for 49 days, the psoriasis area of all subjects was significantly reduced by 42% ± 4%, especially in the erythema index (p = 0.028). Ziyun Ointment significantly reduced the degree of skin transepidermal water loss by 26% (p = 0.04). Conclusion: Ziyun Ointment retains the hydration in the skin and reduces the loss of moisture from the skin. We also suggest that Ziyun Ointment be used for at least 12 weeks to observe significant improvements. Ziyun Ointment has a physiological significance in maintaining skin moisture.