BACKGROUND: During the coronavirus disease 2019 pandemic, wearing medical respirators and masks was essential to prevent transmission.
OBJECTIVE: To quantify the effects of N95 mask usage by measuring facial skin biophysical characteristics and changes in the lipidome.
METHODS: Sixty healthy volunteers wore N95 respirators for 3 or 6 h. Facial images were acquired and physiological parameters were measured in specific facial areas, before and after mask-wearing. Lipidome analysis was also performed.
RESULTS: After N95 respirator usage, facial erythema was observed in both the 3 and 6 h groups. Both sebum secretion and trans-epidermal water loss increased significantly in mask-covered cheeks and chins after 6 h of mask wearing compared with before mask wearing (p < 0.05). Principal component analysis revealed significant differences in lipid composition after mask wearing compared with before. The ceramide subclass NS exhibited a positive correlation with stratum corneum hydration, whereas the AP subclass was negatively correlated with trans-epidermal water loss in the 6 h group.
CONCLUSIONS: Prolonged wear of N95 respirators may impair facial skin function and alter lipidome composition.

UNASSIGNED: Overweight and obesity have become public health problems worldwide. An increasing number of research works are focusing on skin physiology and the manifestations of obesity-associated skin diseases, but little is known about the correlations between body mass index (BMI), facial skin physiological parameters, and the facial skin microbiome in healthy women.
UNASSIGNED: To investigate the correlations between BMI, facial skin physiological parameters and facial bacteria and fungi in 198 women aged 18 to 35 years in Shanghai.
UNASSIGNED: According to the international BMI standard and Chinese reference standard, subjects were divided into three groups, \"lean\" B1, \"normal\" B2 and \"overweight\" B3, and the physiological parameters of facial skin were measured by non-invasive instrumental methods, and the skin microbiota was analyzed by 16S rRNA and ITS high-throughput sequencing.
UNASSIGNED: Compared with the skin physiological parameters of the normal group, those of the overweight group exhibited a significant increase in trans-epidermal water loss (TEWL), which indicated that the skin barrier was impaired. The skin haemoglobin content was significantly increased, and skin surface pH was significant decreased in those with a high BMI. Furthermore, α-diversity, analysed using the Shannon, Chao, Sobs, and Ace indexes, was increased in the overweight group, suggesting that the diversity and species abundance of facial bacterial and fungal microbiota were also increased. Moreover, the overweight group had higher abundances of Streptococcus, Corynebacterium, Malassezia, and Candida. Notably, skin surface pH was significantly and negatively correlated with the relative abundances of Malassezia, Candida, and Cladosporium. Besides, the abundance of Malassezia was positively associated with the abundances of Staphylococcus and Corynebacterium.
UNASSIGNED: These results indicate that BMI is associated with differences in the biophysical properties and microbiome of the facial skin. A high BMI affects the integrity of skin barrier and changes the skin flora diversity and species composition.

The regularity of the menstrual cycle directly affects women\'s health. Many studies have focused on menstrual health; however, menstrual cycle regularity-related variations in skin physiological characteristics and skin microbiota have been seldom investigated.
To investigate the menstrual cycle regularity-related variations in skin physiological characteristics and skin microbiota of 197 cases of Chinese women aged 18-35 years living in shanghai in 2021. Based on a self-evaluation questionnaire, the volunteers were divided into three groups C1 (those with a regular menstrual cycle), C2 (those with a less regular menstrual cycle) and C3 (those with an irregular menstrual cycle). The physiological parameters of facial skin were measured by non-invasive methods and the skin microbiome was analyzed by 16S rRNA high-throughput sequencing.
In the C3 group, the hydration content was significantly decreased (p < 0.05), the TEWL was significantly increased (p < 0.05), and the sebum content was increased (p > 0.05), indicating that the skin barrier integrity weakened with increased menstrual cycle irregularity. Additionally, the melanin level, L value and b value were significantly decreased (p < 0.05) in the C3 group, but the a value was significantly increased (p < 0.001), which indicated that the skin color became darker. Furthermore, the skin microbiota diversity decreased with increasing cycle irregularity, but the differences were not significant. The skin microbiota composition showed that the proportion of Firmicutes, Acinetobacter, Staphylococcus and Cutibacterium were increased in those with an irregular menstrual cycle, indicating that alterations in the ratio of bacterial phyla and/or genera might disturb skin homeostasis. Spearman correlation analysis revealed strong correlations between the microbiota and skin physiological parameters. Based on the associations among hormones, skin physiological parameters and skin microbiota, it is possible that the skin physiological parameters, as well as the skin microbial diversity and composition, change with hormonal fluctuations during the menstrual cycle.
An irregular menstrual cycle can affect skin physiological characteristics and the skin microbiota. Female with an irregular menstrual cycle should strengthen skin care practices and use skin care products with moisturising and soothing effects to protect their skin.

Topical dermatotherapy is intended to be used on diseased skin. Novel drug delivery systems even address differences between intact and diseased skin underlining the need for pre-clinical assessment of different states of barrier disruption. Herein, we studied how short-term incubation in culture media compared to incubation in humidified chambers affects human skin barrier function and viability. On both models we assessed different types and intensities of physical and chemical barrier disruption methods with regard to structural integrity, biophysical parameters and cytokine levels. Tissue degeneration and proliferative activity limited the use of tissue cultures to 48h. Viability is better preserved in cultured tissue. Tape-stripping (50×TS) and 4h sodium lauryl sulfate (SLS) pre-treatment were identified as highly reproducible and effective procedures for barrier disruption. Transepidermal water loss (TEWL) values reproducibly increased with the intensity of disruption while sebum content and skin surface pH were of limited value. Interleukin (IL)-6/8 and various chemokines and proteases were increased in tape-stripped skin which was more pronounced in SLS-treated skin tissue extracts. Thus, albeit limited to 48h, cultured full-thickness skin maintained several barrier characteristics and responded to different intensities of barrier disruption. Potentially, these models can be used to assess pre-clinically the efficacy and penetration of anti-inflammatory compounds.

OBJECTIVE: The physiological characteristics of the skin are varied greatly, depending on gender, age, region and race, and many dermatologic researches have been performed through various research methods. This study aimed to examine how Korean men\'s skin conditions were influenced by temperature or humidity changes caused by seasonal rotations.
METHODS: A total of 100 healthy Korean men, age range 20-59 years, participated in the study for both summer and winter. We compared on the characteristics of skin between summer and winter. The skin hydration, skin pH and TEWL were evaluated on the forehead, cheek and forearm. The skin sebum content of the glabella, nasal ala and cheek was measured using Sebumeter(®) (SM810, Courage+Khazaka, Germany). Cutometer(®) (MPA 580 Courage+Khazaka, Germany) the elasticity was measured by on the cheeks, and PRIMOS lite(®) (Phase shift Rapid in vivo Measurement of Skin, GFMesstechnik GmbH, Germany) was used to evaluate wrinkles on crow\'s feet. Lastly, in addition, the skin pore of the face was measured using the Janus(®) (PSI, Korea) which is a facial analysis system.
RESULTS: The results were as follows: the comparison of hydration in summer and winter shows significant differences in their forehead, cheeks and forearm. The pH values of the skin surface were generally higher in winter, and significantly different on each site, and the sebum content was higher in summer than in winter. As a result of the pore measurement, the summer showed more pores compared to the winter, and there was a statistically significant difference in skin pores between summer and winter. The sensitivity measured by stinging test increases significantly more in winter than in summer. However, there were no seasonal differences in wrinkles and skin brightness.
CONCLUSIONS: The skin surface pH, TEWL, sebum content, hydration, elasticity, wrinkles, skin pore and skin sensitivity vary with seasons and body regions in Korean men.