Transepidermal water loss, temperature and sebum levels on women's facial skin follow characteristic patterns

Background/aims: The aim of this study was to compare the biophysical properties of different facial zones. Methods: We investigated transepidermal water loss (TEWL), skin temperature and sebum casual level (CL) on 90 adjacent test sites distributed on the forehead, cheeks and chin of five women. Results: All three parameters showed a symmetrical distribution around the facial median line. Only minor variations of individual values were found within the forehead and the chin areas. In contrast, the cheeks exhibited a distinct gradient with highest values in the paranasal zones and lowest on the cheek bones for all of the three parameters. The mean values on both cheeks of a given individual were nearly identical, and the patterns within the two cheeks were superimposable. Both CL and skin temperature distributions pointed out a “T‐zone” with highest values on the forehead, on the chin and on the median part of the cheek. Conclusions: Our data demonstrate that biophysical skin properties differ considerably between different facial areas but that they follow a characteristic distribution.     

Regional and seasonal variations in facial sebum secretions: a proposal for the definition of combination skin type

BACKGROUND/AIMS: Facial sebum secretions are known to change under various circumstances. Facial skin types have been categorized as oily, normal, dry, and combination types. However, these have been evaluated subjectively by individuals to date, and no objective accepted standard measurement method exists. The combination skin type is most common, but its definition is vaguer than the definitions of the other skin types. METHODS: We measured facial sebum secretions with Sebumeter. Sebum secretions were measured at five sites of the face seasonally for a year, in the same volunteers. Using the data obtained we developed a set of rules to define the combination skin type. RESULTS: Regional differences in sebum secretion were confirmed. Sebum secretions on forehead, nose, and chin were higher than on both cheeks. Summer was found to be the highest sebum-secreting season, and seasonal variations were found in the T- and U-zones. A mismatch of skin type in the T- and U-zones in more than two seasons appears to be close to subjective ratings of what is described as the 'combination' skin type. CONCLUSION: We showed that the face shows definitive regional and seasonal variations in sebum secretion. To define the combination skin type, seasonal variations in sebum secretion should be considered in addition to regional variations.     

Effects of repetitive superficial chemical peels on facial sebum secretion in acne patients

BACKGROUND: Glycolic acid and Jessner's solution are popular superficial chemical peel agents for the treatment of facial acne, and increased sebum secretion is one of the major aetiological factors of acne. OBJECTIVE: To compare the effects of 30% glycolic acid peels and Jessner's solution peels on sebum secretion in facial acne patients. METHODS: Thirty-eight patients with mild to moderate facial acne were included. Twenty-seven patients were treated with 30% glycolic acid peels and 11 patients with Jessner's solution peels. Each peel was performed twice with an interval of 2 weeks. Before and 2 weeks after each peel, sebum levels of forehead, nose, chin and cheeks were measured by using a Sebumeter (SM810 Courage & Khazaka, Cologne, Germany). RESULTS: The sebum levels were not significantly changed by two peels treatments of 30% glycolic acid peels or Jessner's solution peels on the facial skins of patients with facial acne. CONCLUSIONS: The two types of peels, 30% glycolic acid peels and Jessner's solution peels, did not affect sebum secretion of the facial skins of patients with facial acne after the two peels treatments. The accumulative effects of more than two peels treatments using these modalities need further evaluation.     

Does facial sebum excretion really affect the development of acne?

BACKGROUND: It is generally accepted that the severity of acne is correlated with facial sebum secretion. However, previous studies on the relation between seborrhoea and the development of acne did not consider topographical differences in facial sebum secretion and used relatively vague acne severity grading systems. OBJECTIVES: To elucidate the relation between topographical variations in facial sebum secretion and the severity of acne in women. METHODS: Forty-six female controls and 46 women with acne were included in this study. The Sebumeter was used to measure facial sebum secretion in the following facial areas: forehead, nose, chin, and right and left cheek. We counted noninflammatory comedones and inflammatory acne lesions in the same areas. We compared sebum secretion between patients with acne and controls, and analysed the relation between the quantity of sebum secreted and the number of acne lesions. RESULTS: Sebum secretions in the whole face and in the T- and U-zones (areas of high and low sebum secretion, respectively) were higher in patients with acne than in controls. There was no correlation between sebum quantity and acne lesion count in most facial regions. CONCLUSIONS: Increased levels of facial sebum secretion were observed in patients with acne. Our findings indicate that increased sebum levels do not directly cause development of acne lesions.     

The Difference in Sebum Secretion Affecting Development of Acne

BackgroundAlthough sebum secretion is crucial for acne development, acne lesion distribution is not always similar to the topographic differences of sebum secretion.ObjectiveTo analyze whether sebum secretion affects acne development and distribution and to assess other factors possibly influencing the relationship between acne and sebum secretion.MethodsThis single-center retrospective study included 67 acne patients and 50 controls. Acne patients were divided into 3 groups based on acne lesion distribution: T-zone dominant, U-zone dominant, and mixed groups. The secreted sebum level in each zone of acne patients was compared with that of controls. We also conducted correlation analysis between secreted sebum level and acne number, depending on the facial zone.ResultsNo significant difference was found between acne patients and controls regarding age and sex ratio. The U-zone dominant group showed increased sebum levels compared with controls in the U-zone and whole face, but a similar result was not obtained in the T-zone dominant group. Moreover, there was a significant correlation between the number of lesions and secreted sebum level in the U-zone, but not in the T-zone. Further, there was a more significant relation in the U-zone of male and young patients.ConclusionWe found that increased sebum secretion compared with the condition may affect acne development, especially in the U-zone. Sex and age may also influence the relationship between acne and increased sebum secretion. Acne lesion distribution may vary from patient to patient because sebum secretion affects acne differently depending on multiple factors.     

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.     

痤疮患者皮肤生理功能测定

目的 探讨痤疮患者面部皮肤生理功能的特点，以期指导痤疮患者的治疗。方法 选取受试对象120例，试验组为痤疮患者60例，其中男20例，女40例，平均年龄23.4岁；对照组为健康志愿者60例，其中男20例，女40例，平均年龄25.1岁。运用无创性皮肤生理功能测试仪，测量受试者的面颊及T区（油脂分泌旺盛区域）皮肤油脂、面颊皮肤弹性和水分。结果 试验组面部T区油脂量为（199.98 ± 58.21） μg/cm2，健康对照组为（117.55 ± 63.16） μg/cm2，两组差异有统计学意义（t = 7.34，P < 0.05）。试验组面颊油脂量为（154.45 ± 55.06） μg/cm2，健康对照组为（87.50 ± 47.36） μg/cm2，两组差异有统计学意义（t = 7.14，P < 0.05）。试验组皮肤弹性（0.7931 ± 0.0755R）与健康对照组（0.7882 ± 0.0498R）比较，差异无统计学意义（P > 0.05），试验组皮肤水分（30.75% ± 3.87%）与健康对照组（30.94% ± 2.91%）比较，差异也无统计学意义（P > 0.05）。结论 痤疮患者颜面皮肤油脂分泌过多。     

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.     

Ultraviolet-induced red fluorescence of patients with acne reflects regional casual sebum level and acne lesion distribution: qualitative and quantitative analyses of facial fluorescence

Background The ultraviolet (UV)‐induced red fluorescence of patients with acne has been considered to be caused by Propionibacterium acnes. Objectives To study the correlation of the facial red fluorescence with the casual sebum level and the number of acne lesions and to investigate the difference in clinical features, according to both distribution and proportion of fluorescence. Methods A total of 878 patients clinically diagnosed with acne vulgaris were included. Inflammatory and noninflammatory acne lesions were counted separately. UV fluorescent photography and casual sebum level measurements were performed. UV‐induced fluorescence patterns were classified according to the facial distribution. The proportions of UV‐induced red fluorescence were calculated. Results We identified six different fluorescence distribution patterns in the T‐zone (the forehead, nose and chin) and three different patterns in the U‐zone (both cheeks). The proportion of fluorescence in the U‐zone showed a positive correlation with the casual sebum level and the number of acne lesions. In the T‐zone, the fluorescence proportion correlated with the casual sebum level, but not with the number of acne lesions. As the patients’ age and the age at onset increased, the distribution of fluorescence changed from the upper part of the T‐zone to the lower part, and to the centre of the face in the U‐zone. Conclusions Our results support the hypothesis that the origin of facial red fluorescence is sebum. In patients with acne, analyses of the pattern and proportion of UV‐induced red fluorescence can be useful for evaluating the sebum secretion and selecting efficient treatment modalities.     

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.     

Relation between pH in the Trunk and Face: Truncal pH Can Be Easily Predicted from Facial pH

BackgroundThe clinical symptoms of facial and truncal acne differ. Skin surface acidity (pH), which is affected by sebum secretions, reflects the different clinical characteristics of the face and trunk. However, no studies have been conducted on truncal sebum production and skin pH.ObjectiveWe evaluated the differences and relationship between pH values of the face and trunk. We also evaluated the relationship between pH and the quantity of sebum produced in the trunk.MethodsA total of 35 female patients clinically diagnosed with truncal acne were included. We measured pH on the face and truncal area using the Skin-pH-Meter PH 905®. We measured truncal sebum secretions using the Sebumeter SM 815®. Statistical analysis was performed to evaluate the correlations and differences between pH and sebum.ResultsFacial pH was significantly higher than chest and back pH values. The correlation between pH on the trunk and the face was significant. We used linear regression equations to estimate truncal pH using only measured pH from the chin. There was no significant relationship between truncal sebum secretion and pH.ConclusionThis was the first study that evaluated the differences and correlations between facial and truncal pH. We found that facial pH can predict truncal pH. In addition, we conclude that differences in pH and sebum secretion between the face and trunk are one of the reasons for differences in acne symptom at those sites.     

Topical Spironolactone Reduces Sebum Secretion Rates in Young Adults

The effects of topically applied spironolactone on the sebum secretion rates (SSR) of young adults were investigated. SSR was expressed as the ratio of wax esters/[cholesterol + cholesterol esters] (WE/[C + CE]) and the amount of sebaceous lipids (squalene, triacylglycerol and wax esters). Topical spironolactone 5% gel applied to the right cheeks of the subjects produced a significant reduction in the SSR at 12 weeks (4 weeks after termination of application), but not at 8 weeks (the end of treatment). Untreated “control” areas (the left cheeks of the subjects) showed no significant change during the study. None of the subjects experienced skin rash or signs of local irritation. This results suggests that topical spironolactone may be effective in the treatment of acne patients with high SSR     

The role of facial sebum secretion in acne pathogenesis: facts and controversies

Increased sebum secretion has been known as one of the major pathogenic factors in the development of acne; however, objective sebum measurement methods have been developed only recently. We have limited information about the association of sebum secretion, and the development of acne. There continues to be controversy about the role of sebum in the development of acne. This contribution will discuss sebum measurement techniques and the results of recent studies on the relationship of sebum, facial cosmetic skin type, and acne. New therapeutic modalities for inflammatory acne aim to control seborrhea. Superficial chemical peels, laser treatment for inflammatory acne, and photodynamic therapy are used as adjunctive therapies for acne; however, their sebosuppressive effects are only temporary.     

Evaluation of the effects of 10% and 30% gluconolactone chemical peel on sebum,pH, and TEWL

Background

Gluconolactone (GLA) exhibits antioxidant and moisturizing effects. It also presents soothing effects, protects elastin fibers from UV-induced degradation, and improves the function of the skin barrier.

Aims

Evaluation of skin parameters such as pH, transepidermal water loss (TEWL), sebum levels before, during, and after a series of applications of 10% and 30% GLA chemical peel in a split-face model.

Materials and Methods

The study involved 16 female subjects. Three split-face procedures were performed using two concentrations of GLA solution applied on two sides of the face. The skin parameters were measured before treatments and 7 days after the last procedure at four measurement sites on either side of the face, that is, on the forehead, around the eye, on the cheek, and on the nose wing.

Results

Measurement of sebum demonstrated some statistically significant changes between sebum levels in the cheeks after a series of treatments. The pH measurement showed that the pH value was reduced after each treatment at all measurement points. The level of TEWL after treatments was significantly lower around the eyes, on the left forehead, and on the right cheek. There were no significant differences between the use of different concentrations of the GLA solution.

Conclusions

The results of the study show that GLA has a significant influence on lowering skin pH and TEWL. GLA also has seboregulatory properties.     

Fluorescence diagnostic imaging in patients with acne

Background: Orange‐red fluorescence in the follicle openings, induced by ultraviolet A light, originates from porphyrins, the metabolic products of Propionibacteria acnes. Purpose: To investigate the relationship of orange‐red follicular fluorescence with the severity of acne and the amount of sebum secretion. Methods: Twenty‐five volunteers were included. The severity of acne was rated on a 4‐point scale. The casual sebum level was measured using a Sebumeter and the follicular fluorescence was determined using the camera Visiopor. Results: Casual sebum level and the intensity of fluorescence (percentage of the area and number of orange‐red spots) were higher at the T zone than at the U zone in all patients regardless of their skin type. Sebum amount and area of fluorescence spots were significantly negative in correlation with the clinical grade of acne. There was a significant positive correlation between the orange‐red fluorescence and the casual sebum level. Conclusion: The orange‐red fluorescence showed stronger correlation with the presence of non‐inflammatory acne lesions (comedones) and high sebum amount than the presence of inflammatory acne lesions (pustules) and low sebum amount. The fluorescence diagnostic imaging could be useful in the objective evaluation and monitoring of treatment efficacy in subjects with acne‐prone skin and patients with acne.     

The facial red fluorescence of ultraviolet photography: is this color due to Propionibacterium acnes or the unknown content of secreted sebum?

Background/purpose: Red fluorescence of the face induced by ultraviolet light is thought to be due to Propionibacterium acnes . However, recently there are reports correlating this red fluorescence with the amount of facial sebum secretion. This study was performed to investigate the relationship between the areas of facial red fluorescence with culture results of P. acnes and the amount of sebum secretion.
Methods: Nineteen patients with acne were included. P. acnes cultures were done on specimens obtained from areas with red fluorescence. In addition, the amount of facial sebum secretion and the skin surface pH (SSPH) were measured. Correlation analysis of these parameters and the culture results were performed with the image analysis data from the red fluorescence of the face.
Results: P. acnes was cultured in 36.5% of cases. The correlation of the culture rate with the red fluorescence areas was not significant. After classifying the patients into high-sebum and low-sebum groups, there was a significant difference in the red fluorescence areas. In addition, the red fluorescence area correlated with the SSPH.
Conclusions: The red fluorescence area showed a stronger correlation with sebum secretion than with the presence of P. acnes . This finding suggests that the red fluorescence is affected by sebum not just P. acnes .     

Clinical and instrumental study of the efficacy of a new sebum control cream

Background Some botanical compounds are considered useful to reduce sebum production. Aim To evaluate the efficacy of a sebum control cream containing polyphenol‐rich extract from saw palmetto, sesame seeds, and argan oil in subjects with oily facial skin. Methods The study was carried out during the winter months (January and February). A total of 20 healthy volunteers (9 male and 11 female, aged 17–50 years, 16 with oily skin and 4 with combined skin) were studied. The test product was applied twice daily to the face for a period of 4 weeks. A clinical assessment and instrumental measurements were done before and after the treatment period. Casual sebum level on the forehead and both cheeks was determined with a photometric device (Sebumeter®). The quantity of sebum on the midforehead was determined using sebum collector foils (Sebufix®), which were then evaluated with skin camera Visioscope® and software SELS (Surface Evaluation of the Living Skin). A subjective evaluation questionnaire regarding the cosmetic characteristics, tolerance, and efficacy of the product was filled out by the volunteers at the end of study. Results The product was very well accepted by all the volunteers. A visible sebum‐regulating efficacy was reported in 95% of them. After 4 weeks of treatment, the clinical assessment scores decreased by 33%. There was a significant reduction in the casual sebum level by 20% and area covered with oily spots by 42%. The number of active sebaceous glands remained unaltered. Conclusion These results objectively and quantitatively show the efficacy of the sebum control cream tested to reduce the greasiness and improve the appearance of oily facial skin.     

Efficacy and safety of a facial serum and a mask containing salicylic acid and lipohydroxy acid in acne management: A randomized controlled trial

Background

Inflammatory and non-inflammatory acne lesions constitute a significant clinical challenge in acne subjects.

Aim

To evaluate the efficacy and safety of a facial serum and a mask containing salicylic acid and lipohydroxy acid for improving skin conditions.

Methods

This randomized controlled trial included adults with comedones, post-inflammatory erythema (PIE) and/or hyperpigmentation (PIH) in Shanghai, China in July 2021. Participants were randomly assigned 1:1 to receive the study Serum + Mask or serum alone for 8 weeks. Acne severity, comedones, papules, pustules, PIE, PIH, skin pores, skin tone evenness, sebum secretion, skin hydration, and trans-epidermal water loss were evaluated at T0d, T1d, T7d, T14d, T28d, and T56d.

Results

Eighty-three participants were included, including 41 and 42 in the Serum + Mask and Serum groups, respectively. Acne severity, density of skin pores, skin tone evenness, PIH foci on face, PIE foci on nose, intensity of PIE and PIH, closed comedones on face, open comedones on nose, sebum secretion, and skin hydration were significantly improved from baseline after 8 weeks of treatment in both groups (all p < 0.05). Addition of the mask improved the number of closed comedones (−6.56 ± 0.39 vs. −5.19 ± 0.44, p = 0.022) and acne severity (−0.39 ± 0.08 vs. −0.12 ± 0.09, p = 0.026) substantially more than using the serum alone. No adverse reaction was reported in either group.

Conclusions

The study serum improved skin conditions by regulating skin barrier function and achieving a balance of skin hydration and sebum secretion, removing comedones and improving PIE and PIH. Addition of the mask accelerated the effects without compromising safety.     

Oral spironolactone improves acne vulgaris and reduces sebum excretion

In a consecutive series of thirty-six male and female patients referred with severe acne, the effect of 3 months' treatment with placebo or spironolactone (50-200 mg daily) on sebum excretion and clinical and endocrine status was evaluated double-blind. Twenty-six patients completed the study. Abnormal free androgen indices were found in 27% of the original nineteen female subjects. Spironolactone reduced sebum excretion in all female subjects, but there was no correlation between sebum response and androgen status. The clinical response was dose-dependent, with maximum subjective and objective benefit when spironolactone doses of 150-200 mg were used.     

Evaluation of inherent differences between African American and white skin surface properties using subjective and objective measures

Conflicting data have been published on the inherent differences in skin surface properties among various ethnic groups, though there is a widespread perception that differences exist. This study included subjective and objective assessments of skin surface properties in African American and white subjects. A dermatologist conducted visual assessments of photodamage and irritation. Instrumentation was employed to perform objective measurements of skin surface sebum level, pH, moisture content, and barrier function. In addition, resistance of skin to chemical challenge as a measure of barrier integrity was assessed in a subset of the populations. Results showed differences in photodamage and hyperpigmentation between the 2 ethnic groups tested, but no significant differences between the 2 groups were seen in the results of instrumental measurements for sebum, pH, corneometry (skin moisture), or transepidermal water loss (barrier function). These data help fill the gap in knowledge about photoaging-related differences in the skin of various ethnic groups, especially in textural and pigmentation parameters, as well as increase the knowledge base of differences in objective measures.