Effects of winter indoor environment on the skin: Unveiling skin condition changes in Korea.

BACKGROUND: In Korea, winter can cause skin dryness due to low relative humidity (RH); moreover, indoor heating devices promote moisture loss and air pollution. If dryness persists, dead skin cells accumulate, leading to skin problems; therefore, careful skin care is required. This study aimed to compare changes in skin conditions when exposed to an indoor environment for a short period of 6 h in winter, and to suggest proper winter skin care practices. METHODS: A randomized, split-face clinical study was conducted in which healthy female participants with normal skin were exposed to an indoor environment with a heater turned on for a short period at least 6 h per day in the winter season, and cream was applied to one side of the face. Skin temperature, hydration, sebum, transepidermal water loss (TEWL), elasticity, texture, pores, redness, and wrinkles were measured at the treated and nontreated sites. RESULTS: After 6 h of exposure, skin temperature, pores, roughness, redness, and wrinkles significantly increased (p < 0.05) on the face, whereas TEWL significantly increased on the forearm (p < 0.05). However, sebum secretion appeared to function as a barrier to maintain homeostasis in the facial skin. Elasticity, pores, texture, and wrinkles in the cream-treated ceramide site improved compared to those in the nontreated site (p < 0.05). The moisture content was also significantly higher in the forearm (p < 0.05). CONCLUSION: Changes in skin parameters of participants with healthy skin were observed even after short-term exposure to an indoor environment in winter. Creams containing ceramide maintain skin homeostasis and protect the skin barrier; therefore, it is recommended to use such creams to prevent skin damage and maintain healthy skin, particularly during prolonged exposure to indoor environments during winter.

Evaluation of changes for sebum, skin pore, texture, and redness before and after sleep in oily and nonoily skin.

BACKGROUND: People whose skin type is oily have experienced an esthetic and hygienic discomfort due to the excessive secretion of the sebum during the day and night time, and therefore sebum control is required. In this study, we aimed to find out whether the skin status between the oily and nonoily skin indicates a significant difference before and after sleep. MATERIALS AND METHODS: Forty Korean males and females whose skin type was oily or nonoily participated in this study. To investigate the difference of the skin between oily and nonoily skin before and after sleep, we measured the sebum, skin pore, texture, and redness on their cheek at baseline and after 4-h sleep. Moreover, the significant level was determined at p < 0.05. RESULTS: Parameters of sebum and skin pore significantly increased after 4-h sleep compared with baseline in the oily and nonoily skin (p < 0.05). Moreover, the increment of sebum and pore parameters in the oily skin was significantly higher than those in the nonoily skin (p < 0.05). In the case of skin texture and redness, parameters of them were significantly changed after 4-h sleep compared with baseline only in the oily skin (p < 0.05), and there was no significant difference among groups. CONCLUSIONS: We found that the change rates of the sebum secretion and skin pore in oily skin were significantly higher than those in nonoily skin after 4-h sleep. These results suggest the necessity of the skin care depending on the skin type before sleeping.

The First Human Clinical Trial on the Skin Depigmentation Efficacy of Glycinamide Hydrochloride.

A previous study identified certain low molecular anti-melanogenic peptides that share a common sequence with α-melanocyte stimulating hormone (MSH) and end with a glycinamide moiety. Glycinamide itself also showed anti-melanogenic activity in cell-based assays, but neither glycine nor acetyl glycinamide were active, which indicated a special structure and activity relationship. The aim of this study was to examine the skin depigmentation efficacy of glycinamide hydrochloride in human subjects. The primary skin irritation potential of glycinamide hydrochloride was evaluated by patch testing in 30 human subjects. The skin depigmentation efficacy of glycinamide hydrochloride was evaluated in a double-blinded clinical test in 21 human subjects. The test product and a control product were applied to designated sites on the right or left side of the face twice daily for eight weeks. Skin color parameters, i.e., the melanin index, the L* value (representing skin lightness), a* value (redness), and b* value (yellowness) were measured using instruments. The individual topology angle (ITAo, representing skin color) was calculated from L* and b values. The degree of skin pigmentation was visually assessed by two testers. The primary skin irritation test showed that a solution containing glycinamide hydrochloride up to 10% did not induce any adverse skin responses. In the efficacy test, the test product significantly reduced the melanin index, and increased L* value and ITAo after two weeks of application relative to the baseline value at the start of the test. It also significantly lowered the degree of pigmentation after 6 weeks of application, relative to the baseline value. Differences in the melanin index, L* value, ITAo and the degree of pigmentation between the test and control groups became statistically significant after six weeks or eight weeks of application. No signs of skin irritation were observed during the efficacy test. The present study suggests that glycinamide hydrochloride has great potential to be used in the control of skin hyperpigmentation.

Using reflectance confocal microscopy to observe in vivo melanolysis after treatment with the picosecond alexandrite laser and Q-switched Nd:YAG laser in melasma.

OBJECTIVES: Melasma is an acquired type of hyperpigmentation that is characterized by the appearance of scattered light- to dark-brown macules and patches on the face. Recently, several lasers have been proposed as treatment options for melasma. In particular, the picosecond alexandrite laser is an ideal laser for selective photothermal melanolysis. The aim of our study was to compare the effectiveness in melanolysis of a single treatment of the picosecond alexandrite laser with that of the Q-switched Nd:YAG laser using reflectance confocal microscopy imaging of the melasma lesions. MATERIALS AND METHODS: We performed a spilt-face study using the picosecond alexandrite laser and Q-switched Nd:YAG laser in eight patients with melasma. Both melasma lesions and surrounding normal skin were examined under reflectance confocal microscopy 1 and 24 hours after treatment. The melanin intensity of each skin layer was investigated. RESULTS: At baseline, melasma has irregular melanin distribution and a higher melanin density than surrounding normal skin under reflectance confocal microscopy. After a single treatment with either the picosecond alexandrite laser or the Q-switched Nd:YAG laser, both melanin-induced reflectance and melanin index decreased. CONCLUSION: Our findings suggest that it is feasible to assess the distribution of melanin by reflectance confocal microscopy and observe the melanolysis in melasma lesion after laser treatment. Lasers Surg. Med. 51:423-429, 2019. © 2018 Wiley Periodicals, Inc.