Appearance benefits of skin moisturization

Background/purpose: Skin hydration is essential for skin health. Moisturized skin is generally regarded as healthy and healthy looking. It is thus speculated that there may be appearance benefits of skin moisturization. This means that there are corresponding changes in the optical properties when skin is moisturized. Methods: The appearance of the skin is the result of light reflection, scattering and absorption at various skin layers of the stratum corneum, epidermis, dermis and beyond. The appearance benefits of skin moisturization are likely primarily due to the changes in the optical properties of the stratum corneum. We hypothesize that the major optical effect of skin moisturization is the decrease of light scattering at the skin surface, i.e., the stratum corneum. This decrease of surface scattering corresponds to an increase of light penetration into the deeper layers of the skin. An experiment was conducted to measure the corresponding change in skin spectral reflectance, the skin scattering coefficient and skin translucency with a change in skin hydration. In the experiment, skin hydration was decreased with the topical application of acetone and alcohol and increased with the topical application of known moisturizers and occlusives such as PJ. Result and conclusion: It was found that both the skin spectral reflectance and the skin scattering coefficient increased when the skin was dehydrated and decreased when the skin was hydrated. Skin translucency increased as the skin became moisturized. The results agree with the hypothesis that there is less light scattering at the skin surface and more light penetration into the deeper skin layers when the skin is moisturized. As a result, the skin appears darker, more pinkish and more translucent.     

The difference between the constitutive and facultative skin color does not reflect skin phototype in Asian skin

BACKGROUND/PURPOSE: The assessment of the sensitivity of human skin to ultraviolet (UV) radiation is important in the area of phototherapy, photodermatoses, photo-aging, photo-carcinogenesis, and photo-protection. Some reports have shown that quantitatively measured skin color is a good indicator for predicting UV sensitivity to human skin in Caucasians. In this study, our aim was to define the correlation between skin color and the skin phototype assessed by the Fitzpatrick method in Asian brown skin. METHODS: A total of 180 medical students with similar life styles were included in this study. Their skin phototype was classified according to the system introduced by Fitzpatrick. Then, using a Minolta Spectrophotometer CM-2002, their skin color was determined on the buttocks and forehead. The buttock color was taken as the constitutive skin color, and the forehead color as the facultative skin color. Using these measured values, we compared the skin color with the skin phototype to find their correlation. Also, we investigated whether the difference between the constitutive and facultative skin colors of each individual had a relationship with his or her skin phototype. RESULTS: The constitutive skin color became darker with increasing skin phototype, and this change was statistically significant. As for the facultative skin color, it also became darker with increasing skin phototype, but was less well correlated with the skin phototype than the constitutive skin color. However, the difference between the constitutive and facultative skin colors did not show consistent results in predicting the skin phototype. CONCLUSION: In this study, we found that the constitutive skin color can be a good indicator of the skin phototype. However, the difference between the constitutive and facultative skin colors of each individual does not give any meaningful information for the assessment of his or her skin phototype in Asian skin.     

Effect of skin pH for wrinkle formation on Asian: Korean,Vietnamese and Singaporean

Background Skin pH may be influenced by various factors, such as hydration of stratum corneum, rate of sebum excretion rate, transepidermal water loss (TEWL) and sweating in relation to skin ageing. Objective The aim of this study was to evaluate the correlation between skin pH and wrinkle formation that is directly related to ageing. In addition, we investigated the factors related to skin ageing by comparing the association between skin pH and other skin properties. Methods Three hundred volunteers were selected from three countries: Korea, Vietnam and Singapore. Hydration on the stratum corneum, the rate of sebum excretion rate, melanin index, TEWL and skin temperature on the cheek were measured in a controlled room, and wrinkle length and depth using replicas were compared with skin pH variation. Results The mean and standard deviation of skin surface pH among the three countries were 5.510 ± 0.625. The greatest gap of skin pH that revealed significant differences for skin properties was represented between the Koreans and the Vietnamese. For all three countries, skin hydration, melanin contents, wrinkle length, wrinkle depth and skin temperature were significantly correlated with skin pH. Factors related to skin moisturizing, such as skin hydration, sebum excretion rate and skin temperature, were negatively correlated with skin pH. Wrinkle length and depth decreased as skin pH became more acidic. Conclusions Skin properties displayed various values depending on skin pH. In particular, wrinkle formation significantly decreased as skin pH becomes more acidic. We conclude that skin pH is determined by skin properties, such as skin hydration, sebum excretion rate, melanin concentration, TEWL and skin temperature that affects wrinkle formation.     

Possible functional impairment of Langerhans' cells in vitiliginous skin. Reduced ability to elicit dinitrochlorobenzene contact sensitivity reaction and decreased stimulatory effect in the allogeneic mixed skin cell lymphocyte culture reaction

We used patch testing to compare the ability to elicit contact sensitivity to dinitrochlorobenzene (DNCB) of uninvolved with vitiliginous skin of 31 patients with vitiligo. The induction of DNCB contact sensitivity was possible in the vitiliginous skin in the same way as in normal skin. The DNCB contact sensitivity reactions, however, were generally diminished in vitiliginous skin, although the number of cases showing similar DNCB contact reactivity between normal and vitiliginous skin increased when the sensitization procedure was performed in vitiliginous skin instead of normal skin. On the other hand, delayed skin reactions to intradermally injected Candida albicans antigen were not suppressed in vitiliginous skin. The number of Langerhans' cells was not decreased in vitiliginous skin as compared with that of normal skin. The epidermal cells derived from vitiliginous skin, however, tended to show a lower stimulatory effect in the allogeneic mixed skin cell lymphocyte culture reaction than those from normal skin. These results suggest a possibility of functional impairment of Langerhans' cells in vitiliginous skin.     

A minimally invasive tool to study immune response and skin barrier in children with atopic dermatitis

Atopic dermatitis (AD, atopic eczema) is a very common skin condition affecting 10-20% of children. It affects children of all skin colours and seems to occur more often in Asian children and children with dark skin types. However, most research is performed on children with light skin types. This study, performed in Amsterdam, the Netherlands, aimed to investigate differences between AD in children with dark and light skin types. To study this, the investigators took tape strips from 53 AD children aged 0-12 years and 50 healthy children as control (comparison). Tape stripping is a painless procedure which is ideal to perform in children, in which a small round sticker is attached to the skin. When removing this special sticker, a thin layer of skin cells remains attached to the sticker, allowing the investigators to study several aspects of skin inflammation and skin barrier. The authors found that AD skin from children with light and dark skin have similar levels and types of skin inflammation. However, they found differences in skin barrier markers between these two groups. In light skinned children, markers of good skin barrier were lower in AD skin when compared to healthy children's skin, while in dark AD skin these skin barrier markers were not significantly different from healthy dark skin. This study showed that dark-skinned and light-skinned AD children are similar when it concerns skin inflammation, but in light skinned AD children the skin barrier dysfunction may play an additional role in the development of AD. This suggests that AD in light and dark skin has different mechanisms of development.     

Involvement of melanocortin-1 receptor in the hyperpigmentation of human skin autografts

Hyperpigmentation frequently occurs in human skin autografts resulting in an unsatisfactory appearance. This study aimed to elucidate the role of melanocortin-1 receptor in the hyperpigmentation process of skin autografts by analyzing the expression of melanocortin-1 receptor. The data were correlated with the amount of melanin in autografted human skin and normal skin determined in a previous study. Immunohistochemistry, western blotting and quantitative real-time polymerase chain reaction were carried out to detect the expression and distribution of melanocortin-1 receptor in skin autografts including full-thickness skin autografts, split-thickness skin autografts and normal full-thickness skin. Fontana-Masson stain was used to detect melanin in all types of skin specimens. The expression level of melanocortin-1 receptor in autografted skin was much higher than that in control normal skin, and thinner split-thickness skin autografts had higher levels of expression of melanocortin-1 receptor than thicker grafts. The amount of melanin in skin autografts was significantly increased compared with normal skin. The expression of melanocortin-1 receptor correlated well with the amount of melanin in the epidermis of skin autografts. These results indicate that melanogenesis is dramatically enhanced in skin autografts by the melanocortin-1 receptor, and suggest that overexpression of melanocortin-1 receptor may play an important role in the hyperpigmented process of skin autografts. This study provides a novel mechanism for hyperpigmentation in skin autografts.     

敏感性皮肤发病机制及其相关皮肤病的研究进展

敏感性皮肤常表现为皮肤受到轻微外界刺激后易产生不适感觉（包括潮红、瘙痒、烧灼、刺痛等）。敏感性皮肤发病机制主要涉及皮肤神经系统、皮肤屏障功能、皮肤血管系统、转录组学、反安慰剂效应等多方面。不少其他皮肤病（如特应性皮炎、玫瑰痤疮等）可伴敏感性皮肤的症状,易误诊误治。本文综述了敏感性皮肤的发病机制及相关皮肤病。     

Impact of atopic skin diathesis on occupational skin disease incidence in a working population

Present evidence convincingly indicates that workers with occupational skin disease are more frequently affected by atopic skin diathesis than the general working population. Population-based studies estimating the impact of atopic skin diathesis on occupational skin disease in various occupations have not been reported to date. We analyzed data of all initial reports of occupational skin diseases recorded in the register of occupational skin diseases in northern Bavaria, Germany, from 1990 to 1999. The main outcome measure was the attributable risk of atopic skin diathesis on occupational skin disease within 24 occupational groups that are most hazardous to the skin. Of the 5285 registered cases, 3730 had a confirmed occupational causation. Among these, 1366 workers (37%) presented an atopic skin diathesis. Assuming a prevalence of atopic skin diathesis of 20% in the total population, we found that 21.6% (95% confidence interval 19.4; 23.7) of occupational skin disease cases within 24 occupational groups may be ascribed to this endogenous risk factor. The attributable risk of atopic skin diathesis helped to explain a large proportion of occupational skin diseases. Empirical evidence supports the importance of surveying atopic skin diathesis as part of an occupational skin disease prevention strategy.     

Incontinence induces stratum corneum vulnerability and impairs the skin barrier function in the perianal region

BACKGROUND: Incontinence leads to a reduced skin barrier function, while also increasing the risk of skin breakdown. AIM: To investigate the perianal skin barrier function of elderly patients with or without incontinence. METHODS: We compared the skin barrier function by investigating the skin hydration, the skin pH, the amount of ceramide and by making a dermatological skin inspection of the perianal region in patients with and without incontinence. RESULTS: Twenty-one incontinent patients (70.0%) showed a glossy skin, which indicates impairment of the skin barrier while none of the patients in the continence group did so. In the incontinence group, those who had a glossy skin showed a significantly greater skin pH and total amount of ceramide than those with a normal skin (p = 0.0099, p = 0.0179, respectively). CONCLUSIONS: These results demonstrate that a glossy skin may be a useful indicator of a reduced perianal skin barrier function.     

Increased E-selectin, IL-8 and IL-10 gene expression in human skin after minimal trauma

While clinical observations suggest that trauma to the skin plays a critical role in the induction of skin lesions in some skin diseases, the mechanism by which these lesions are induced is not known. We have postulated that minor trauma to the skin may lead to the expression of critical adhesion molecules on epidermal endothelial cells (E-selectin) and pro-inflammatory cytokines, which would predispose these areas to the development of skin lesions. In order to test this hypothesis normal inner arm skin of 11 normal subjects was gently rubbed with a pencil eraser for 2 min. Four hours after rubbing, skin biopsies were obtained from the rubbed site and from adjacent normal, unrubbed inner arm skin. Expression of E-selectin, intercellular adhesion molecules (ICAM-1) and the mRNA of selected cytokines was studied utilizing real time polymerase chain reactions. Biopsies were also examined for the presence of an inflammatory infiltrate and for the presence of E-selectin and ICAM-1. No clinical or histologic changes were seen in the skin expression/unrubbed skin expression = 9.0; (median ratio rubbed skin expression/unrubbed skin expression range 0.9-161.0), ICAM-1 (median rubbed skin expression/unrubbed skin expression = 3.2; range 0.9-19.8), IL-8 (median rubbed skin expression/unrubbed skin expression = 6.6; range 2.6-57.3) and IL-10 (median rubbed skin expression/unrubbed skin expression = 13.1; range 2.4-29.0) was noted. Immunohistochemistry revealed the presence of E-selectin in the dermal blood vessels in three of four subjects 4 h after rubbing but not in the unrubbed skin. Changes in ICAM -1 or HLA-DR deposits were seen in the rubbed compared with the unrubbed skin. These findings demonstrated that minor trauma to skin may induce expression of E-selectin, ICAM-1 and IL-8, which may make the skin a more permissive site for the development of inflammatory reactions. These findings may play an important role in the development of skin lesions in areas of minor trauma.     

人工皮肤在紫外线对皮肤作用中的研究进展

人工皮肤作为人体皮肤形态及功能的类似物,成为研究紫外线对人体皮肤作用的新型体外模型.近5年来,国内外在光生物学领域主要用其研究皮肤光损伤的形态学、分子机制及开发防护及修复光损伤制剂.同时结构更完善的皮肤模型在该研究领域的引进,为组织工程化皮肤在紫外线皮肤损伤的基础及临床研究提供新思路.     

Noxious heat and scratching decrease histamine-induced itch and skin blood flow

The aim of this study was to assess the effect of thermal stimuli or distal scratching on skin blood flow and histamine-induced itch in healthy volunteers. Twenty-one healthy volunteers participated in the study. Baseline measurements of skin blood flow were obtained on the flexor aspect of the forearm. These measurements were compared with skin blood flow after various stimuli: heating the skin, cooling the skin, noxious cold 2 degrees C, noxious heat 49 degrees C, and scratching via a brush with controlled pressure. Afterwards histamine iontophoresis was performed and skin blood flow and itch intensity were measured immediately after the above-mentioned stimuli. Scratching reduced mean histamine-induced skin blood flow and itch intensity. Noxious heat pain increased basal skin blood flow but reduced histamine-induced maximal skin blood flow and itch intensity. Cold pain and cooling reduced itch intensity, but neither affected histamine-induced skin blood flow. Sub-noxious warming the skin did not affect the skin blood flow or itch intensity. These findings suggest that heat pain and scratching may inhibit itch through a neurogenic mechanism that also affects skin blood flow.     

Stratum corneum hydration and skin surface pH in patients with atopic dermatitis

Atopic dermatitis (AD) is a chronically relapsing skin disease with genetic predisposition, which occurs most frequently in preschool children. It is considered that dryness and pruritus, which are always present in AD, are in correlation with degradation of the skin barrier function. Measurement of hydration and pH value of the stratum corneum is one of the noninvasive methods for evaluation of skin barrier function. The aim of the study was to assess skin barrier function by measuring stratum corneum hydration and skin surface pH of the skin with lesions, perilesional skin and uninvolved skin in AD patients, and skin in a healthy control group. Forty-two patients were included in the study: 21 young and adult AD patients and 21 age-matched healthy controls. Capacitance, which is correlated with hydration of stratum corneum and skin surface pH were measured on the forearm in the above areas by SM810/CM820/pH900 combined units (Courage AND Khazaka, Germany). The mean value of water capacitance measured in AD patients was 44.1 ± 11.6 AU (arbitrary units) on the lesions, 60.2 ± 12.4 AU on perilesional skin and 67.2 ± 8.8 AU on uninvolved skin. In healthy controls, the mean value was 74.1 ± 9.2 AU. The mean pH value measured in AD patients was 6.13 ± 0.52 on the lesions, 5.80 ± 0.41 on perilesional skin, and 5.54 ± 0.49 on uninvolved skin. In control group, the mean pH of the skin surface was 5.24 ± 0.40. The values of both parameters measured on lesional skin were significantly different (capacitance decreased and pH increased) from the values recorded on perilesional skin and uninvolved skin. The same held for the relation between perilesional and uninvolved skin. According to study results, the uninvolved skin of AD patients had significantly worse values of the measured parameters as compared with control group. The results of this study suggested the skin barrier function to be degraded in AD patients, which is specifically expressed in lesional skin.     

Elemental analysis mirrors epidermal differentiation

Using a scanning nuclear microprobe, the distribution of elements and trace elements of skin cross sections of normal skin, non-lesional psoriatic skin and in dry atopic skin have been mapped. In non-lesional psoriatic skin and in dry atopic skin the epidermal Ca-gradient is higher than that of normal skin. In addition, abnormally high Fe and Zn levels were recorded in the stratum granulosum and corneum regions in the pathological skin. It is suggested that these findings correlate to an increased cell turnover in the basal cell layer of the psoriatic and atopic skins. The ratio of Ca/Zn in stratum corneum of paralesional psoriatic skin is approximately 8:1 compared to 12: 1 in normal skin and 15: 1 in atopic skin. This suggests that the differentiation process in paralesional psoriatic skin may actually be an example of disturbed programmed cell death.     

Standardized trauma (tape stripping) in human vulvar and forearm skin. Effects on transepidermal water loss, capacitance and pH.

Mechanical trauma to genital skin may favor the transmission of sexually transmitted diseases. To study differences between vulvar and forearm skin in epidermal repair after standardized trauma, transepidermal water loss, capacitance and pH of forearm and vulvar skin in 10 healthy premenopausal women were monitored for 7 days after a standardized trauma induced by tape stripping to glistening. Vulvar and forearm skin showed similar responses immediately after tape stripping: a sudden increase in transepidermal water loss and capacitance. Forearm skin, however, reacted more intensely than vulvar skin; forearm skin readings remained significantly higher than normal values for 2 days after tape stripping, whereas vulvar skin readings were not significantly different from normal. Thus, vulvar skin did not respond as extensively as forearm skin, presumably because it is a less complete barrier against excess body water loss. On the other hand, vulvar skin seemed to recover faster from skin damage than forearm skin, probably because of its higher epidermal cell turnover.     

Acute bacterial skin and skin structure infections: current perspective

A skin and skin structure infection is a bacterial infection of skin and associated tissues. It may be complicated skin and skin structure infection or uncomplicated skin and skin structure infection. Recently, the Food and Drug Administration has called them acute bacterial skin and skin structure infections (ABSSSI). ABSSSI are common and encompass a variety of disease presentations and severity. Increased antimicrobial resistance among both Gram-positive and Gram-negative bacteria with methicillin-resistant Staphylococcus aureus is the main problem in treatment. So, development of newer agents to fight against resistant microbes is the need of the hour. Ceftaroline, a newer cephalosporin, is one promising agent.     

人工皮肤在紫外线对皮肤作用中的研究进展

人工皮肤作为人体皮肤形态及功能的类似物,成为研究紫外线对人体皮肤作用的新型体外模型.近5年来,国内外在光生物学领域主要用其研究皮肤光损伤的形态学、分子机制及开发防护及修复光损伤制剂.同时结构更完善的皮肤模型在该研究领域的引进,为组织工程化皮肤在紫外线皮肤损伤的基础及临床研究提供新思路.     

与紫外线致皮肤损伤相关的部分信号通路研究进展

紫外线照射可使皮肤损伤,导致皮肤光老化或皮肤肿瘤.多个信号通路如Nrf2-Keap1-ARE、核因子κB、丝裂原活化蛋白激酶(MAPK)、磷脂酰肌醇-3激酶-丝氨酸/苏氨酸激酶-西罗莫司靶蛋白(PI3K-AKt-mTOR)信号通路等参与皮肤光老化和(或)皮肤肿瘤的发病.Nrf2信号通路在氧化应激状态下开启,有维持氧化还原平衡和参与细胞新陈代谢等作用.核因子κB信号通路的激活引起基质金属蛋白酶等水平上调,与皮肤老化和非黑素性皮肤癌有关.MAPK信号通路参与皮肤老化和皮肤肿瘤的进展.PI3K-AKt-mTOR信号通路主要与皮肤肿瘤相关.紫外线照射可诱导上述通路的活化,参与皮肤光老化或皮肤肿瘤的发生发展.对上述通路的进一步研究有望为抵御皮肤的光老化和皮肤肿瘤提供新的方法.     

Efficacy of the combined use of a facial cleanser and moisturizers for the care of mild acne patients with sensitive skin

Acne is a common skin disease that involves the seborrheic area of the face and results from the obstruction of hair follicles followed by inflammation. Careful face washing helps to improve and prevent acne; however, intensive washing has a risk of inducing skin barrier impairment and dry skin, especially in sensitive skin. We hypothesized that skin care combining mild skin cleansing and intensive moisturizing (“combination skin care”) may be effective in the care of acne in subjects with dry skin and/or sensitive skin. We developed a combination skin care with a weakly acidic foaming facial skin cleanser based on a mild detergent, an aqueous lotion with eucalyptus extract and a moisturizing gel containing pseudo‐ceramide and eucalyptus extract. To optimize an ideal facial skin care system for mild acne on sensitive skin, we performed a 4‐week clinical trial with 29 post‐adolescent Japanese women with mild acne with dry and sensitive skin. The acne significantly decreased after this trial accompanied by the improvement of dry skin, a significantly increased endogenous ceramide level in the stratum corneum and an elongated alkyl chain length of the non‐hydroxy acyl sphingosine type ceramide. No adverse events due to the test samples were observed. Based on diagnosis by a dermatologist, 97% of the subjects found the combination skin care to be “useful” or “slightly useful”. Based on these findings, the combined use of a facial skin cleanser and moisturizers is safe and effective for the care of acne in post‐adolescent Japanese women with sensitive skin.