Background and Objectives: Evidence suggests the importance of skin biophysical properties in predicting diseases and in developing appropriate skin care. The results to date of studies on skin surface pH, stratum corneum (SC) hydration and sebum content in both genders and at various ages have been inconclusive, which was in part due to small sample size. Additionally, little is known about the skin physical properties of Asian, especially Chinese, subjects. In the present study, we assess the difference in skin surface pH, sebum content and SC hydration at various ages and in both genders in a large Chinese population without skin diseases. Methods: 713 subjects (328 males and 385 females) aged 0.5–94 years were enrolled in this study. The subjects were divided by age into 5 groups, i.e., 0–12, 13–35, 36–50, 51–70 and over 70 years old. A multifunctional skin physiology monitor was used to measure SC hydration, skin surface pH and sebum content on both the forehead and the forearms. Results: In males, the highest sebum content was found on the forearm and the forehead in the age groups 36–50 (93.47 ± 10.01 μg/cm²) and 51–70 years (9.16 ± 1.95 μg/cm²), while in females, the highest sebum content was found on the forearm and the forehead in the age groups 13–35 (61.91 ± 6.12 μg/cm²) and 51–70 years (7.54 ± 2.55 μg/cm²). The forehead sebum content was higher in males aged 13–70 years than in age-matched females; the sebum content on the forehead in both males and females was higher than that on the forearm. Skin surface pH on the forehead of both males and females over the age of 70 years was higher than that in younger groups. SC hydration on the forehead in both males and females was lower above the age of 70, and the one in males aged 13–35 was higher than that in females (43.99 ± 1.88 vs. 36.38 ± 1.67 AU, p < 0.01). SC hydration on the forehead in both males and females did not significantly differ from that on the forearm. Conclusions: In a large Chinese cohort, the skin surface pH, sebum content and SC hydration vary with age, gender and body site.

Research from JAMA Dermatology — Improvement of Naturally Aged Skin With Vitamin A (Retinol)

Research from JAMA — Treatment of Acne Vulgaris With a Pulsed Dye Laser — A Randomized Controlled Trial — ContextThe high prevalence of acne vulgaris and its significant morbidity underscore the need for convenient, low-risk, and efficacious therapy. Treatment with various lasers has been reported to improve acne.ObjectiveTo evaluate the clinical efficacy of pulsed dye laser therapy in the treatment of acne.Design, Setting, and PatientsRandomized, single-blind, controlled, split-face clinical trial of a volunteer sample of 40 patients aged 13 years or older with facial acne conducted at an academic referral center from August 2002 to September 2003.InterventionOne or 2 nonpurpuric pulsed dye laser treatments to half of the face (fluence of 3 J/cm2), serial blinded clinical assessments (lesion counts), and grading of acne severity using standardized bilateral serial photographs.Main Outcome MeasuresComparison of the changes in lesion counts from baseline to 12 weeks between treated and untreated sides of the face and changes in photographic evidence of acne severity as graded by a panel of dermatologists blinded to treatment assignment.ResultsAfter 12 weeks, using intent-to-treat analysis with last observation carried forward, there were no significant differences between laser-treated and untreated skin for changes in mean papule counts (−4.2 vs −2.2; P = .08), mean pustule counts (0 vs −1.0; P = .12), or mean comedone counts (2.9 vs 1.6; P = .63). Grading of serial photographs confirmed the clinical assessments, showing no significant mean (SE) differences in Leeds scores (range, 1-12) for treated skin (3.98 [0.32] at baseline and 3.94 [0.27] at week 12) compared with untreated skin (3.83 [0.32] at baseline and 3.79 [0.28] at week 12) (P>.99).ConclusionsIn this study, the nonpurpuric pulsed dye laser therapy did not result in significant improvement of facial acne. More research is needed before this laser therapy may be recommended as an acne treatment.