An optimal method for quantifying the facial sebum level and characterizing facial sebum features.

BACKGROUND: Evidence suggests that sebum content is important in skin disorders such as acne. However, sebum levels change depending on the external environment, and quantifying skin sebum levels is challenging. Here, we propose an optimal method for quantifying the facial sebum level. MATERIALS AND METHODS: Four hundred and sixty participants (160 males and 300 females) aged 20-40 were enrolled in this study. A Sebumeter SM 810 was used to measure the sebum level at five facial locations: the forehead, the chin, the left cheek, the right cheek, and the nose. The participants were divided into two groups; one group underwent a one-time measurement (n = 390, male: female = 120: 270), and the other underwent three consecutive measurements (n = 70, male: female = 40: 30). The casual sebum level (CSL) was measured in all patients after a 30-min acclimatization; subsequently, the sebum removal process was conducted, followed by a resting period of 1 h to determine the sebum excretion rate (SER). Spearman's correlation analysis and the Wilcoxon signed-rank test were used to compare the sebum level consistency and differences between the groups. RESULTS: Although three consecutive measurements better reflected the sebum content, the one-time measurement also represented the relative sebum level. One hour after sebum removal, the sebum level recovered to 70%-90%; thus, this method was applicable for use in SER quantification. Of the five testing points, the sebum content was highest in the nose and lowest in the cheeks (both left and right). In addition, the cheeks were the most stable sites in terms of testing points, testing times, and CSL/SER values. A one-time measurement of the CSL could represent the SER 1 h after the sebum removal. In our cohort, the sebum level of males with oily skin was decreased at age 32-35, and that of males with non-oily skin increased at 28-35. The opposite trend was observed in female participants. CONCLUSION: Sebum measurement methods were assessed, including testing times, indices (interval of time) and sites in a conditioned external environment. A one-time measurement of the CSL 1 h after sebum removal was sufficient to determine the sebum level and SER, and the cheeks are recommended as the testing site. Sex and skin type differences were observed in sebum level changes with age.

ARTICLE: Compromised Skin Barrier and Sensitive Skin in Diverse Populations.

The most important function of the stratum corneum (SC), the uppermost layer of the human epidermis, is the formation of the epidermal permeability barrier. Lipids, particularly ceramides, cholesterol, and free fatty acids, together form lamellar membranes in the extracellular spaces of the SC that limit the loss of water and electrolytes. In addition to preventing water and electrolyte loss, the SC as a permeability barrier prevents the entry of harmful irritants, allergens, and microorganisms into the skin. Disruption of the epidermal barrier leads to skin that is irritated, more reactive, and more sensitive than normal skin. SC thickness, lipid profile, and barrier function vary with different ethnic groups, which is also reflected the differences in prevalence and manifestation of diverse skin conditions related to the skin barrier function such as atopic dermatitis and sensitive skin. In addition to these compromised skin barrier related conditions, we are just now starting to understand the direct and indirect impact of COVID-19 on the skin and how current preventative measures are contributing to skin barrier disorders. Our understanding of various approaches for restoration of skin barrier, especially the role of topically applied mixtures of cholesterol, ceramides, and essential/nonessential free fatty acids (FFAs) allows for the strengthening of the compromised skin barrier and alleviation of symptoms and discomfort associated with skin barrier disorders. Ceramide containing products on the market are commonly available and offer protection and reparative benefits to the skin barrier. J Drugs Dermatol. 20(4 Suppl):17-22. doi:10.36849/JDD.S589C.

Pilot investigation of the hydrating effects of topical acne medications.

Topical therapies are effective in managing acne vulgaris but are associated with local adverse effects such as irritation and dryness. This 4-week pilot study compared skin hydration in 36 healthy adult women randomized to treatment with 1 of 4 topical therapies: 2 different (jar and tube) clindamycin 1%/benzoyl peroxide 5% gels, sodium sulfacetamide 10% lotion, or over-the-counter (OTC) moisturizing cream. Subjects treated with OTC moisturizer or sodium sulfacetamide exhibited decreased water loss, increased water retention, similar or improved levels of skin hydration, and decreased desorption rates. In contrast, subjects treated with jar or tube clindamycin/benzoyl peroxide had increased water loss, decreased water retention, decreased hydration, and increased desorption rates. Skin dryness decreased slightly in the moisturizer group. No serious adverse events occurred. Overall, the OTC moisturizer had the best skin hydration profile. Sodium sulfacetamide demonstrated some moisturizing characteristics, and no clinically relevant differences were noted between jar and tube clindamycin/benzoyl peroxide gels.

Experimental studies on the nature of sensitive skin.

BACKGROUND: In the USA, Europe and Japan 40 to 50% of women report that they have sensitive skin, defined as abnormal sub-clinical sensory responses to drugs, cosmetics and toiletries in the absence of visible signs of irritation. Itching, burning, stinging and tightness are the commonest complaints, which mainly afflict women. Manufacturers of skin care products have made available a large variety of products which are designed for persons with sensitive skin. Such products are not required by regulatory agencies to submit evidence of safety and efficacy, allowing marketers to make claims that are often exaggerated, irrational and even preposterous. The consumer with self-assessed sensitive skin has no way of judging which products are likely to be most beneficial and least harmful. The marketplace is awash with products for which there is no evidence that the rosy claims have been substantiated by appropriate testing procedures. There is no internationally accepted consensus regarding the criteria which define sensitive skin. Many papers have been published in the last 15 years, mainly originating from industry, which express widely differing views regarding what constitutes sensitive skin. For some, any adverse reaction to a product topically applied to sensitive skin, including breakouts, redness, scaling etc., a panoply of adverse reactions which is virtually meaningless. Others include environmental factors as causative, including cold, dry wind, heat and high humidity, solar radiation, etc., which add to the manifest complexities of the subject. METHODS: This is the first paper in a series which provides a comprehensive review of the subject, emphasizing the all too many controversies and confusions arising from the lack of a consensus regarding the identification, classification, epidemiology, prevalence and pathogenesis of sensitive skin. Sensitive skin is a biologic reality and not a psychological, fashionable fantasy on the part of impressionable women. RESULT/CONCLUSION: There is an urgent necessity to establish rigorous methodologies for estimating the quality and severity of sensitive skin, a heterogeneous condition involving multi-factorial factors. Subsequent papers in this series will describe in detail the experimental approach our group has used to bring some clarity and credibility to this querulous, but important subject.

Intense pulsed light treatment of photoaged facial skin.

BACKGROUND: It has been reported that intense pulsed light is efficacious for rejuvenation of photoaged skin, specifically the improvement of appearance of telangiectases and solar lentigines. OBJECTIVE: The objective was to define the treatment variables for photodamaged facial skin using a newer intense pulsed light system. METHODS: Twenty-three female subjects received three treatments using double-stacked pulses with fluences of 24 and 30 J/cm2. Response to treatment was evaluated using digital photography. Three signs of photoaging were evaluated: surface texture/roughness, mottled hyperpigmentation, and erythema/telangiectases. RESULTS: There was a shift in clinical grading from more to less severe on all three measures of photoaging. CONCLUSION: Intense pulsed light therapy was efficacious in ameliorating the clinical signs of photoaging. The device was well tolerated with minimal side effects.