Facial skin physiology recovery kinetics during 180 min post-washing with a cleanser.

BACKGROUND/PURPOSE: Facial cleansing is important to clean and exfoliate the skin while maintaining optimal physiologic function. However, there is insufficient data on the very early stage of skin change after applying soap or cleansing foam. We investigated the recovery kinetics of facial skin physiology during 180 min after exposure to the cleanser. METHODS: For the study, 22 Korean female subjects with normal and dry to oily skin type were recruited in this study. Study subjects were required to have face washing done within the 12 hours prior to visiting the research center, with only toner, lotion, or cream applied. The next day, the subjects visited the research center without face washing. We evaluated the skin hydration (Corneometer(®) CM 825), sebum (Sebumeter(®) SM 815), transepidermal water loss (Tewameter(®) TM 300), and pH (Skin-pH-Meter(®) PH 905) to define recovery kinetics of facial skin physiology during 180 min exposure post-cleansing. RESULTS: Skin hydration, sebum, and TEWL were significantly decreased at 20 min after washing, as compared to the baseline (P < 0.05). And skin hydration returned at 40 min, and skin sebum and TEWL returned at 120 min after washing. However, skin pH did not show significant differences at all times points. CONCLUSIONS: This study indicated that each of the skin parameters was restored at defined time points post-cleansing. Our result could be a useful reference to set the resting time in the estimation of skin bioengineering parameters.

Dermal matrix affects translucency of incident light on the skin.

BACKGROUND/AIMS: The age-dependent changes in the optical reflection characteristics have been studied about skin hydration, melanin index, or skin color. However, the age-dependent changes in the optical reflection have little attention on inner skin structures. To control the factors affecting the optical reflection except for dermal matrix, subjects were selected as our guideline and we evaluated the optical reflection of subsurface on skin layers of two age groups. METHOD: Young and old healthy volunteers were recruited after signing a written informed consent form. Facial skin was measured by means of noninvasive measurements: skin hydration, color, epidermis and dermis thickness, dermal density, subsurface reflectance, and transmittance. RESULT: Compared to young group, old group showed that dermal density and thickness was decreased significantly although epidermis thickness was not changed. CONCLUSION: In conclusion, dermal density is one of the major factors which affects the subsurface reflectance in skin.