Treatment of Aged Skin with a pH 4 Skin Care Product Normalizes Increased Skin Surface pH and Improves Barrier Function: Results of a Pilot Study

The physiological skin surface pH is just below 5. With age the skin surface pH increases up to 6. An increased pH correlates with reduced barrier integrity/cohesion. The present pilot study assesses possible normalization of an increased skin surface pH of the elderly and improvement of barrier function via application of ≈pH 4.0 skin care products. Baseline skin surface pH was determined in elderly (80+ years old;n = 15) compared to middle aged adults (31 - 50 years old;n = 15). The effect of o/w emulsions at pH-values of 3.5, 4.0, 4.5 and 5.5 on the skin surface pH was determined in both groups. Further, the effect of a 4-week treatment with a pH 4.0 skin care product on the skin surface pH, skin hydration and barrier integrity was assessed. Thirteen elderly females were involved in this home-in-use test. Increased baseline skin surface pH of the elderly normalizes to the physiological pH of 4.5 - 5.0 over 7 hours after single application of o/w-emulsions with a given pH of 3.5 or 4.0. A 4 week treatment employing the pH 4.0 skin care product improves the epidermal barrier integrity of the elderly significantly (p = 0.005). Reduction of the increased baseline skin surface pH of the elderly is accompanied by improved epidermal barrier integrity. Skin care products for the elderly have to be adjusted in the pH range of 3.5 to 4.0.

Correlation Demodex Folliculorum and Skin Biophysical Parameters

Purpose: Demodex folliculorum is a transparent mite, 0.3 - 0.4 mm long, which asymptomatically parasitizes the human pilosebaceous follicles. D. folliculorum is observed in normal skin with a prevalence of 100% and a density of ≤ 5 D/cm2 in the adult population. Materials and Methods: This study evaluated the differences in pH on the five facial sites between the two populations with and without D. folliculorum. The relationship between pH and skin surface oil was analyzed in populations with and without Demodex mites. Mongolian 750 subjects (370 males and 380 females) aged 16 - 84 years, who lived in Ulaanbaatar city, were enrolled in this study. The eligibility criteria included a minimum age of 16 and no physical and dermatologic illness, no cosmetic. Results: Skin surface oil among the five facial areas differed significantly in both subjects with and without Demodex folliculorum (P < 0.001). When the skin surface oil on the T-zone, U-zone was compared, those on the T-zone were significantly higher than those of the U-zone (P < 0.001) in both populations (P< 0.01). The pH levels on the five facial sites, and U-zone, T-zone and MFpH differed significantly in among both subjects with and without Demodex folliculorum (P < 0.001). In both groups, the pH levels of the U-zone were significantly lower than the pH of the T-zone (P Conclusions: Among the five facial sites in subjects with Demodex folliculorum, there were significant negative correlations between skin surface oil and pH on the forehead (p < 0.001, r = 652), cheek (P < 0.001, r = 0.656), nose (P < 0.001, r = 0.754), chin (P < 0.001, r = 0.679), and T-zone (P < 0.001, r = 0.698), MFSE-MFpH (P < 0.001, r = 0.483). In contrast, among the five sites in subjects without Demodex folliculorum, a significant negative correlation between skin surface oil and pH was observed on the forehead (p < 0.001, r = 766), cheek (P < 0.001, r = 0.798), nose (P < 0.001, r = 0.706), chin (P < 0.001, r = 0.823), and T-zone (P < 0.001, r = 0.602), U-zone (P < 0.001, r = -0.550)

皮肤表面pH值及其临床意义

皮肤表面pH值是皮肤的生理指标之一,它随机体的不同生长发育时期和皮肤的生物状态的不同而不同。老年人及新生儿皮肤表面pH值较高;某些皮肤病可导致皮肤表面pH值升高。皮肤表面pH值升高可直接或间接影响角质形成细胞的代谢,从而引起角质形成细胞增生、分化的异常,皮肤屏障功能改变,角质层致密性降低等。因此,测量皮肤表面pH值对判断表皮乃至整个机体的生物状态具有重要参考价值;皮肤表面pH值维持在最佳生理水平对延缓皮肤老化、防止和治疗某些皮肤病具有一定的指导意义。

局部外用砷制剂对鼠角质层致密性的影响

目的:研究砷是否引起皮肤角质层功能的改变,为探索砷治疗皮肤病提供实验依据。方法:6～8周龄的裸鼠背部和躯干两侧分别外涂基质、0.5mmol/L和1.5mmol/L三化二砷。每日2次,每次60μL,共2周。用Courage-Khazaka多功能皮肤生理仪测量皮肤表面的基础黑素(melanin)含量、角质层含水量、皮肤表面皮脂含量、皮肤通透屏障功能及角质层的酸碱度。此外,对皮肤屏障功能的恢复速度、角质层的致密性也进行测量。结果:在此动物模型中,0.5mmol/L和1.5mmol/L的二三氧化二砷均导致角质层pH值升高和角质层的致密性降低:1.5mmol/L的三氧化二砷增加皮肤的黑素含量。与对照组相比,0.5mmol/L和1.5 mmol/L的三氧化二砷对角质层含水量、基础皮肤通透屏障功能以及屏障功能的恢复速度均无明显的影响。虽然两种浓度的砷均引起皮肤表面皮脂含量的轻微增加,但与对照组相比,差异无统计学意义。结论:砷可以引起角质层生理功能的改变,可以导致皮肤对砷通透性增加。在预防或治疗皮肤砷中毒时,增强角质层的防御功能是不可忽视的环节。

慢性阻塞性肺病稳定期患者表皮功能改变及其临床意义

目的探讨肺部疾病患者与健康老人表皮生物物理特性是否存在差别。方法于2022年1月~3月收集50例慢性阻塞性肺病(COPD)老年患者和50例无肺病健康老年志愿者(61~91岁)。用GPSkin Barrier检测仪测量角质层含水量和经皮水分丢失率,用便携式酸碱度仪测量皮肤表面pH。结果(1)两组间面部、左臂和左腿的透皮水分丢失率无显著差异;(2)COPD患者左臂和左腿的角质层含水量显著降低(P<0.01),而面部角质层含水量无显著差异;(3)COPD患者左臂和左腿皮肤表面PH值显著高于无肺病者(P<0.01),但是面部皮肤表面pH无显著差异。结论COPD的老年患者皮肤衰老加速,表现为皮肤角质层含水量下降和皮肤pH值升高。对于COPD患者,修复表皮功能具有重要的临床意义。

皮肤表面酸碱度稳态动力学的研究

目的:探索皮肤保持其表面pH稳定状态的动力学。方法:利用丙酮和胶带急性破坏表皮通透屏障功能、中波紫外线(UVB)照射及局部外用碱性物质的方法提高皮肤表面pH值。然后,在不同的时间观察皮肤表面pH的改变,依此判断皮肤表面pH保持稳定状态的动力学。结果:在丙酮模型中,表皮通透屏障功能破坏48 h后,皮肤表面的pH恢复正常;而在胶带模型中,表皮通透屏障功能破坏48 h后,皮肤表面的pH值仍明显地高于基础值(P<0.01);在紫外线模型中,UVB照射6 d后,皮肤表面的pH才恢复正常;局部外用碱性物质6 h后,皮肤表面pH恢复正常。结论:皮肤维持其表面pH稳定状态的动力学因诱导pH紊乱的因素不同而不同。

亚临床皮肤刺激后三种生理参数的变化

目的探讨经表皮失水（TEWL）、皮肤电容量（CAP）、皮肤表面pH值参数在亚临床刺激性皮炎诊断中应用的可能性。方法通过1％十二烷基硫酸钠（SIS）开放性斑贴、10次胶带粘贴及0．75最小红斑量UVB照射三种不同的刺激方法，对30名健康女性受试者的前臂屈侧进行处理，共5d。每天刺激之前进行临床评估。试验第0，6，7，8天进行TEWL、CAP及皮肤表面pH值检测。结果所有受试者8天内临床评分均为0分；SLS刺激后第6，7，8天TEWL值分别为3．17±3．07（g／m^2h）、3．32±2．84（g／m^2h）、3．22±2．36（g／m^2h），较基础值0．40±1．35（g／m^2h）升高，差异均有统计学意义（均为P=0．00）。SLS刺激后第6，7，8天CAP值较基础值下降，皮肤表面pH值较基础值升高，与基础值间差异均有统计学意义（P〈0．05）。胶带粘贴后第6，7，8天TEWL值分别为2．54±1．85（g／m^2h）、2．40±2．16（g／m^2h）、2．17±1．99（g／m^2h），较基础值0．11±1．10（g／m^2h）升高，差异均有统计学意义（均为P=0．00）；胶带粘贴后第8天，皮肤表面pH值较基础值升高，差异有统计学意义（P=0．00）；CAP无明显变化。0．75MED UVB照射后各生物物理参数均无明显变化。结论三种生物物理参数可以被用于亚临床性刺激性接触性皮炎的检测。不同参数对不同的刺激方法检测能力不同。

面部皮肤表面p H值影响过氧苯甲酰凝胶治疗Ⅱ级痤疮疗效的临床观察

目的探讨面部皮肤表面pH值对过氧苯甲酰凝胶治疗Ⅱ级痤疮疗效的影响。方法196例寻常痤疮患者,分为低、中、高皮肤表面pH值组,早、晚外用过氧苯甲酰凝胶各1次,6周后评估疗效。结果男女面部皮肤表面pH值差异无统计学意义(P> 0. 05);男性患者全面部、T形区和女性患者T形区,中、高p H值组的疗效均优于低pH值组(P <0. 05)。结论皮肤表面pH值能显著影响过氧苯甲酰凝胶的疗效,且对男性患者的影响更大。