Functional properties of the surface of the vermilion border of the lips are distinct from those of the facial skin

BACKGROUND: The vermilion border of the lips (lip for short) is the only part on the face where the oral mucosa is persistently exposed to the outside. Despite its prominent presence on the face, constituting not only the target of cosmetics but also the site for various skin diseases, its functional properties remain almost unknown. OBJECTIVES: To elucidate the functional properties of the vermilion border of the lips. METHODS: We studied the biophysical properties of the lip by comparing them with those of the cheek skin in 303 healthy Japanese females aged 21-80 years, in winter. We used a closed-chamber system to measure transepithelial water loss (TEWL) of the lip to avoid the effect of breathing. Moreover, we examined the effects of oral etretinate, a drug that definitely produces dry, scaly lips, on the lips of seven male patients aged 49-89 (average 67) years. RESULTS: TEWL was significantly almost three times as high on the lips as that on the cheek which is a site that shows far higher levels than do other body areas. TEWL decreased with age more remarkably on the lip than on the cheek. High-frequency conductance, a parameter for surface hydration state, was significantly lower on the lip than on the cheek. The mean values obtained were about one-third of those on the cheek, and no age-related changes were observed either on the lip or on the cheek. The superficial epithelial cells on the lip were parakeratotic and larger than those of the cheek skin. Furthermore, we detected a significant increase in TEWL on the lip as well as on the cheek of patients treated with oral etretinate. CONCLUSIONS: It appears that the incomplete corneocyte formation of the lip surface is responsible for the poor barrier function and water-holding capacity.     

Comparison of cheek and forehead regions by bioengineering methods in women with different self-reported "cosmetic skin types"

Background/aims: Understanding structural and functional differences between facial areas is necessary for the formulation of cosmetics and dermatological preparations well tailored to the skin's biophysical characteristics. The objective of the present study was to compare biophysical parameters on malar and frontal facial areas of healthy women classified according to self-reported cosmetic skin types.
Methods: The study population comprised 253 women aged from 20 to 50 years who did not display any signs of dermatological disease. Women declared spontaneously their cosmetic skin type. Skin capacitance, sebum casual level, skin temperature, transepidermal water loss (TEWL), skin colour and relief were assessed on cheeks and forehead in a controlled environment.
Results: All biophysical parameters showed statistically significant differences between the two zones. Mean a* chromametric values and TEWL values were significantly higher on cheeks. In contrast, mean b * chromametric values and sebum casual levels showed the highest values on the forehead. Moreover, skin capacitance, temperature, roughness and L .* chromametric value showed minor, while statistically significant, differences between the two zones. With marginal exceptions, the differences between the facial zones for each biophysical parameter remained statistically significant, irrespective of self-reported skin type.
Conclusion: Biophysical parameter mean values differ between frontal and malar zones regardless of self-reported skin type. Except for the elevated sebum casual levels in "greasy" and "combined" skin, no single or combined biophysical characteristics could be linked to any of the self-reported skin types. Furthermore our data confirm that in contrast to the common belief that "dry" skin is associated with reduced sebum production, sebum levels in women declaring to have "dry" skin and those declaring to have "normal" skin were not found to be different.     

Comparative Measurement of Biophysical Parameters in Consideration of Skin Graft Donor Site for Nasal Defects

BackgroundIn planning a skin graft, the texture, color, and size of the recipient and donor site tissues should be considered.ObjectiveWe determined the optimal donor sites for nasal full-thickness skin grafting based on biophysical parameters.MethodsThirty women over the age of 60 were selected for this study. Four recipient sites (nasal root, dorsum, tip, ala) and three donor sites (preauricle, postauricle, forehead) were considered. Biophysical parameters such as transepidermal water loss (TEWL), capacitance, sebum output, erythema/melanin value, and skin replica technique were tested.ResultsThe nasal root was correlated with the forehead in terms of TEWL and sebum output. The nasal dorsum was correlated with the preauricle in terms of TEWL, erythema/melanin value, and skin replica measurements. The nasal tip was correlated with the preauricle in terms of TEWL, sebum output, erythema/melanin value, and skin replica measurements. The ala was correlated with the forehead in terms of TEWL and skin replica measurements.ConclusionThe preauricule is the optimal donor site for resurfacing of the nasal dorsum and tip. The forehead is a good donor site for alar defects. For resurfacing of the nasal root, the forehead and postauricle are good choices.     

Fluorescent image analysis for evaluating the condition of facial sebaceous follicles

Background/purpose: Conventional methods, such as 'Sebutape' and 'Sebumeter,' can provide quantitative information on sebum excretion but cannot reflect the condition of sebaceous follicles that can be indirectly evaluated with fluorescent colors of sebum. The images of sebum excretion can be obtained with an ultraviolet-A light that is generally called 'Wood's Lamp.' In this study, we describe fluorescent image analysis methods for the detection of sebum and the color segmentation of sebum to evaluate the condition of sebaceous follicles.
Methods/results: For subject-dependent automatic image analysis, we extracted calibrated image analysis methods that were optimized for digital fluorescent images acquired from our imaging system. The calibrated subjective threshold values for sebum detection were determined by statistically analyzing the number of sebum detected by the automatic threshold value method and the subjective threshold value method ( R =0.947, the number of volunteers: 29). In fluorescent color analysis of sebum, the calibrated reference color markers for the red and white colors were extracted with a coefficient of variance of <10%.
Conclusion: We are confident that such calibrated image analysis methods in combination with our imaging system can provide useful quantitative diagnostic information for sebum-related skin pathologies.     

Evaluation of facial skin type by sebum secretion: Discrepancies between subjective descriptions and sebum secretion

Background/aims: Facial skin is usually classified as dry, normal, and oily in the cosmetics field. However, there is no standard objective method for classifying facial skin.
Methods: We measured sebum excretion with Sebumeter^® at four sites on the face. Based on the amount of sebum secretion, we reclassified skin type according to the guidelines provided by the manufacturer. The mean of sebum excretion (mean facial sebum excretion; MFSE) was also calculated.
Results: People secrete varying amounts of sebum at different skin sites. Reclassification of skin type based on sebum secretion revealed that most participants underestimated the amount of facial sebum excretion. When sebum secretion amounts were compared, a statistically significant difference was apparent between the oily and dry skin types. However, there were no statistical differences between oily and normal, and normal and dry skin.
Conclusion: We showed that subjective skin type does not match the amount of sebum secreted. Thus, this simple and subjective classification is of very limited use and it should be re-evaluated by using an objective and standardized measuring tool.     

昆明地区成年女性面部皮肤屏障功能检测

目的 了解昆明地区成年女性皮肤屏障功能在年龄及部位上的差异.方法 将150名昆明地区（18 ～70）岁的女性志愿者分为3个不同年龄组,分别为：青年组（18～ 34岁）、中年组（35 ～ 49岁）及老年组（50～70岁）,每组50人.采用无创性皮肤检测仪对志愿者的左侧面颊部及额中部进行水分、油脂及TEWL的检测.结果 青年组面颊部水分（38.46±5.70）、油脂（60.70±35.78）及额中部水分（39.57±5.08）、油脂（104.56±45.40）含量最高,老年组面颊部水分（31.00±6.09）、油脂（26.87±16.71）及额中部水分（32.54±5.84）、油脂（39.67±24.44）含量最低.而面颊部TEWL（10.76±3.95）及额中部TEWL（10.13±3.76）均在青年组检测值最低.各年龄组女性额中部的油脂明显高于面颊部,差异均有统计学意义（P＜0.05）,每个年龄组面颊部水分与额中部水分比较,面颊部TEWL与额中部TEWL比较均无明显差异（P＞0.05）.结论 昆明地区成年女性面颊部及额中部水分、油脂随年龄增长而逐渐减少,而TEWL值随年龄增长逐渐增大.     

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.     

4%5-氨基酮戊酸光动力疗法治疗痤疮疗效分析及对皮肤生理指标的影响

目的观察4%的5-氨基酮戊酸光动力疗法(ALA-PDT)治疗痤疮的疗效,以及对皮脂、肤色和皮肤屏障功能等皮肤生理指标的影响。方法对20例面部中重度痤疮患者,采用4%的ALA-PDT治疗3次,治疗结束后继续随访8周。分别计数炎症性和非炎症性皮损判定疗效。采用无创测试仪器测量皮肤生理指标。结果 3次治疗后,患者面部炎症性皮损和非炎症性皮损均显著减少(P<0.05)。治疗后患者皮脂分泌减少;皮肤屏障功能相关的生理指标如皮肤角质含水量、pH值和TEWL值等得到改善(P<0.05)。患者皮肤颜色L值和a值在治疗期间有变化,但治疗结束后1～2个月恢复到治疗前水平。结论 4%ALA-PDT治疗中重度痤疮疗效肯定,并可以减少皮脂分泌,对于皮肤屏障功能的影响很小,对于肤色的影响是暂时的。     

Mapping the human face: biophysical properties

Background: Facial skin exhibits unique biophysical properties that are distinct from skin belonging to other areas of the body. Small to large regional differences in biophysical properties between facial sites are observed. Technological advances in dermatological research allow a quantitative study of the biophysical qualities of the face and its relation to skin elsewhere. However, comprehensive studies examining inter‐regional variations using each of the six standard biophysical parameters have been few. We summarize findings on the biophysical parameters used to explore the human face as well as regional differences in skin reactivity to chemical irritants. Methods: We performed a literature search using Pubmed, Embase, Science Citations Index, and the UCSF's dermatological library on biophysical parameters and skin physiology pertaining to the human face. Results: Distinct regional differences in transepidermal water loss (TEWL), capacitance, blood flow, sebum, pH, and temperature were demonstrated in facial skin. However, studies cannot be compared with each other because each uses different anatomical sites, skin conditions, and measurement techniques. Intraregional differences in TEWL, sebum, and temperatures were observed on the cheeks and appeared to follow characteristic distribution patterns. Higher blood flow levels and skin temperatures were generally observed in areas with dense networks of blood vessels such as the nose and perioral region. Areas such as the forehead, nose, and chin consistently showed higher sebum casual levels, but variability in sebum levels between sites was also observed. The susceptibility of the face to hexyl nicotinate, sodium lauryl sulfate, and benzoic acid differed depending on location and age. Conclusion: Establishing a standardized biophysical profile of the human face will help to improve therapeutics, and further our understanding of differences in chemical reactivity and disease distribution. Future research necessitates standardization of the anatomical sites studied, sample size, and experimental protocols.     

Biophysical parameters of skin: map of human face, regional, and age-related differences

The face showed anatomical variation on reaction to chemicals, which could be related to differences in biophysical specificities of the skin. The aim of this study was to establish a map of the face for 6 biophysical parameters.10 young human volunteers (24-34 years) and 10 old volunteers (66-83 years) were studied to prepare a map of the human face based on regional variations and age-related differences by measuring various biophysical parameters. 7 locations on the face, neck, and forearm were investigated. Skin blood flow, transepidermal water loss (TEWL), stratum corneum hydration (capacitance), temperature, pH, and sebum content of the skin surface were measured. In both groups, skin blood flow in the nose showed the highest value. Perioral and nasolabial areas showed the highest TEWL values. The neck showed the highest capacitance value. The highest skin temperature was detected in the neck in the young group and in the nasolabial area in the old group. The chin showed the most alkaline pH in both groups. Nasolabial area showed the highest sebum content in the young group, as did the chin in the old group. These baseline values provide a framework to build on for ascertaining disease and intervention-related effects.     

Improving lip wrinkles: lipstick-related image analysis

BACKGROUND/PURPOSE: The appearance of lip wrinkles is problematic if it is adversely influenced by lipstick make-up causing incomplete color tone, spread phenomenon and pigment remnants. It is mandatory to develop an objective assessment method for lip wrinkle status by which the potential of wrinkle-improving products to lips can be screened. The present study is aimed at finding out the useful parameters from the image analysis of lip wrinkles that is affected by lipstick application. METHODS: The digital photograph image of lips before and after lipstick application was assessed from 20 female volunteers. Color tone was measured by Hue, Saturation and Intensity parameters, and time-related pigment spread was calculated by the area over vermilion border by image-analysis software (Image-Pro). The efficacy of wrinkle-improving lipstick containing asiaticoside was evaluated from 50 women by using subjective and objective methods including image analysis in a double-blind placebo-controlled fashion. RESULTS: The color tone and spread phenomenon after lipstick make-up were remarkably affected by lip wrinkles. The level of standard deviation by saturation value of image-analysis software was revealed as a good parameter for lip wrinkles. By using the lipstick containing asiaticoside for 8 weeks, the change of visual grading scores and replica analysis indicated the wrinkle-improving effect. As the depth and number of wrinkles were reduced, the lipstick make-up appearance by image analysis also improved significantly. CONCLUSION: The lip wrinkle pattern together with lipstick make-up can be evaluated by the image-analysis system in addition to traditional assessment methods. Thus, this evaluation system is expected to test the efficacy of wrinkle-reducing lipstick that was not described in previous dermatologic clinical studies.     

Multiple parameter assessment of vulvar irritant contact dermatitis

Transepidermal water loss (TEWL), capacitance, pH, blood flow and color reflectance were evaluated for quantifying the irritant response of vulvar and forearm skin to 3% sodium lauryl sulfate in 9 healthy premenopausal women. TEWL, capacitance, pH, blood flow, and all parameters of color reflectance changed significantly in forearm irritant dermatitis. In vulvar irritant dermatitis, however, significant changes were observed only for blood flow and the color reflectance parameters a* and b*. Using the combination of TEWL, capacitance and blood flow, forearm irritant dermatitis was detected with a sensitivity of 84% and a specificity of 100%. In this study, the best combination of parameters to detect vulvar irritant dermatitis was pH, blood flow, a* and b*, which had a sensitivity of 78% and a specificity of 75%. It is concluded that available bioengineering techniques are less suitable to quantify irritant dermatitis in the vulva than in the forearm.     

Biophysical characteristics of skin in diabetes: a controlled study

Background  Cutaneous complications are common in diabetes. Previous assays suggest that hyperglycemia and decreased insulin signal are involved in the impairment of skin function. The aim of this study was to evaluate the biophysical characteristics of skin in patients with diabetes mellitus and compares them with healthy non-diabetic controls.
Objective  To measure biophysical characteristic of skin including transepidermal water loss (TEWL), water content, sebum and skin elasticity in patients with diabetes mellitus and compare them with healthy non-diabetic controls.
Methods  This case-control study was conducted on 38 patients with diabetes and 40 age- and sex-matched healthy people. The biophysical properties of skin including stratum corneum (SC) hydration, sebum content, TEWL and skin elasticity were measured and compared between the two groups at three different locations of the body.
Results  The measurement of SC hydration and TEWL showed no significant difference between diabetics and controls. The skin surface lipids on the forehead but not other sites were significantly lower in the diabetics than in the controls. Acoustic wave propagation speed, a measurement related to skin elasticity, was significantly lower in forearm and forehead of diabetics.
Conclusion  Diabetes affects some functional properties of epidermis and dermis that may responsible for many cutaneous manifestations of diabetes. These results suggest that patients with diabetes mellitus tend to show a normal hydration state of the SC together with decreased sebaceous gland activity and impaired skin elasticity, without any impairment of the SC barrier function.

Conflicts of interest

None declared     

Different Cosmetic Habits Can Affect the Biophysical Profile of Facial Skin: A Study of Korean and Chinese Women

BackgroundPrevious studies on the age-, climate, and skin care habit-related changes of biophysical parameters have mainly focused on Caucasians, and studies on Asians are in paucity.ObjectiveThis study was aimed to investigate the variations of cutaneous biophysical parameters in Chinese and Korean women (northeast Asians) and to assess the association between those parameters and age, climate, and cosmetic habits.MethodsA cross-sectional study included 361 healthy Chinese and Korean women between 18 and 49 years of age in 4 cities (Guangzhou, Nanjing, and Shijiazhuang in China, and Suwon in Korea). We measured skin surface temperature, hydration, transepidermal water loss (TEWL), sebum, elasticity, skin pore, wrinkle, and skin tone (brightness) using non-invasive instruments. Demographic profiles and cosmetic habits were assessed using a questionnaire.ResultsSkin elasticity and tone decreased, and pore size and wrinkle increased with age. Subjects in Suwon (Korean) showed higher hydration level, lower TEWL and lower sebum, less severe wrinkle and brighter skin than those in the 3 cities in China. After adjusting for age and region, using sunscreen everyday, wearing base makeup daily, and using moisturizers improved hydration, TEWL, and elasticity significantly.ConclusionWomen in Suwon (Korea) were found to have a better profile of biophysical parameters than women in the 3 Chinese cities, which might be attributed to cosmetic habits, besides age and climatic factors. The fact that appropriate cosmetic habits are associated with favorable skin biophysical parameters underscores the importance of daily skin care routine in preserving skin functions.     

The effects of severe growth hormone deficiency on the skin of patients with Sheehan''s syndrome

BACKGROUND: Growth hormone (GH) may play an important role in the content and appearance of the skin. Dry, thin and pale skin has been described in hypopituitarism. Sheehan's syndrome is characterized by anterior pituitary dysfunction due to postpartum pituitary necrosis and GH is one of the hormones lost first. OBJECTIVE: The aim of this study was to examine the hydration of the skin of patients with Sheehan's syndrome using measurements of capacitance, sebum content, transepidermal water loss, pH and temperature. The data were compared with those of control subjects. METHODS: A total of 21 patients with Sheehan's syndrome and 20 women as control subjects were included in this blinded prospective study. Hormone deficiencies other than GH had been adequately replaced. The diagnosis of GH deficiency (GHD) was established by the insulin tolerance test (ITT). Skin properties were measured by non-invasive and well-established methods. RESULTS: The skin capacitance had decreased on the forehead and forearm and sebum content had decreased on the forehead of patients with Sheehan's syndrome when compared with control subjects. The pH, temperature and average transepidermal water loss (TEWL) of the skin of the patients were not statistically different from the controls. CONCLUSION: GHD results in a decrease in skin capacitance and sebum content indicating that GH and/or insulin-like growth factor-I (IGF-I) have an important role in skin function.     

Physiology of the vellus hair follicle: hair growth and sebum excretion

The growth of vellus hair and the secretion of sebum from vellus hair follicles were measured on the forehead, cheek, chest, shoulder and back of healthy men and women aged 15-30 years. Hair growth was assessed by computerized image-analysis of photographs and sebum excretion by the use of Sebutape followed by image analysis. The density of vellus hairs and the percentage of growing hairs were higher on the face than on the thorax (439 hairs/cm2 with 49% growing hairs on the forehead compared with 85 hairs/cm2 with 31.5% growing hairs on the back). The rate of growth ranged from 0.03 mm/day on the forehead to 0.13 mm/day on the back. The maximum length of vellus hair significantly decreased with age; otherwise hair growth was not affected by age or sex. Some variations in hair growth and sebum secretion were observed over a period of 3 months, but no consistent rhythms were detected. There was no obvious link between vellus hair growth and sebum excretion.     

Correlation between stinging, TEWL and capacitance

Background/aims: To study the correlation between stinging and skin barrier and to make the lactic acid stinging test much safer.
Methods: The modified lactic acid stinging test with 3% and/or 5% aqueous solution of lactic acid combined with transepidermal water loss (TEWL) and capacitance (CAP) was used. The amount of 50 µL-test material was applied on test areas, the skin of both sides nasolabial fold of 50 healthy subjects. Subjects assessed stinging basing on a 4-point scale at 0, 2.5, 5.0 and 8 min TEWL and CAP were measured at baseline and 8 min.
Results: The results show that the tendency of decrease in baseline CAP and increase in baseline TEWL are proportional with the increase of the sum of clinical scores (CS_S) . In 5% lactic acid test, negative correlation between changing ratio of TEWL (P_TEWL) and clinical score at 5 min (CS_5 min), and negative correlation between changing ratio of capacitance (P_CAP) and CS_5 min are registered.
Conclusion : Our data indicate that there is certain relationship between the degree of stinging and the skin barrier. The stinging test method modified by lower concentration aqueous lactic acid and the assessment combined with P_TEWL and P_CAP is suitable for Chinese to evaluate the skin susceptibility.     

Variations of skin biophysical properties after recreational swimming

Background/purpose: Sensations of itching and skin tightness are frequently reported after recreational swimming in pool water. Our objective was to measure the potential changes occurring at the skin surface under such conditions.
Methods: Nine women participated in this study, which consisted of two periods. During a 4-day control period, basal biophysical skin parameters were assessed every morning. On the first day, measurements were also performed in the afternoon. The second study period followed the same study design as for the control period, except that, on the first day, women swam for 1 h in a public pool, between the measurements performed in the morning and the afternoon. Skin capacitance, transepidermal water loss, skin temperature, skin pH and sebum casual level (SCL) were measured on facial and body sites.
Results: During the control period, biophysical skin parameters did not show significant variations. By contrast,      h after swimming, biophysical values showed significant changes for all test sites: skin pH increased, whereas skin capacitance and SCL decreased. Biophysical parameters returned to baseline values the day after swimming.
Conclusion: Our results demonstrate that recreational swimming leads to significant transient changes in skin surface properties of women with healthy skin.     

Skin aging. Effect on transepidermal water loss, stratum corneum hydration, skin surface pH, and casual sebum content.

This study investigates the effect of cutaneous aging on transepidermal water loss, stratum corneum hydration (capacitance), skin surface pH, and causal sebum content. Because the physiologic condition of skin varies considerably with anatomic region and skin aging might demonstrate regional variability, all factors were studied on 11 anatomic locations in 14 young adult (seven female and seven male subjects; 26.7 +/- 2.8 years [mean +/- SD]) and 15 aged human volunteers (seven female and seven male subjects; 70.5 +/- 13.8 years). Significant anatomic variability was noted for all factors in both age groups. However, no significant differences between the two groups were noted for sebum, capacitance, and pH on most anatomic regions. Transepidermal water loss, however, was significantly lower in the aged population on all anatomic regions tested, except for the postauricular region and the palm. Comparing male and female volunteers, none of the four factors showed significant differences. Of all measured factors, only transepidermal water loss showed significant age-related differences on most anatomic regions studied. The additionally observed differences between the age groups on the ankle for pH and sebum might be related to the stasis frequently observed on the lower limbs in aged individuals.