Oily skin: specific features in Chinese women

Unveiling the Metabolomic Profile of Oily Sensitive Skin: A Non-Invasive Approach

Skin barrier impairment is becoming increasingly common due to changes in lifestyle and modern living environments. Oily sensitive skin (OSS) is a condition that is characterized by an impaired skin barrier. Thus, examining the differences between OSS and healthy skin will enable a more objective evaluation of the characteristics of OSS and facilitate investigations of potential treatments. Initially, a self-assessment questionnaire was used to identify patients with OSS. Biophysical measurements and LAST scores were used to determine whether skin barrier function was impaired. Epidermal biophysical properties, including skin hydration, transepidermal water loss (TEWL), sebum content, erythema index (EI), and a* value, were measured with noninvasive instruments. We subsequently devised a noninvasive D-square sampling technique to identify changes in the skin metabolome in conjunction with an untargeted metabolomics analysis with an Orbitrap Q ExactiveTM series mass spectrometer. In the stratum corneum of 47 subjects, 516 skin metabolites were identified. In subjects with OSS, there was an increase in the abundance of 15 metabolites and a decrease in the abundance of 48 metabolites. The participants with OSS were found to have the greatest disruptions in sphingolipid and amino acid metabolism. The results revealed that an impaired skin barrier is present in patients with OSS and offers a molecular target for screening for skin barrier damage.

Questionnaire and Lactic Acid Sting Test Play Different Role on the Assessment of Sensitive Skin: A Cross-sectional Study

BACKGROUND

Questionnaires and lactic acid sting test (LAST) are two widely used methods to identify sensitive skin. However, the self-perceived sensitive skin by questionnaires was not consistent with the determination of LAST.

OBJECTIVE

The aim of the study was to measure the biophysical properties noninvasively of sensitive skin evaluated by questionnaire and LAST and to investigate their correlations with the scores of questionnaire and LAST.

METHODS

A total of 209 healthy Chinese females completed the study. Self-assessment questionnaire and LAST were both performed to identify sensitive skin. Epidermal biophysical properties, including skin hydration, transepidermal water loss (TEWL), sebum content, erythema index (EI), a* value, L* value, skin elasticity, and skin pH, were measured with noninvasive instruments.

RESULTS

The frequency of sensitive skin was 50.2% and 66.0% by questionnaire and LAST, respectively. Subjects with self-assessed sensitive skin had a slightly higher LAST positive rate. Skin hydration, sebum content, a* and EI values were significantly higher in the self-assessed sensitive skin group, while TEWL, a* and EI values increased but L* value decreased with significance in the LAST positive group. The LAST stingers among sensitive skin subjects had higher EI but not in the healthy skin subjects. In addition, questionnaire scores positively correlated with skin hydration, sebum content, a* and EI values, while a positive relationship of LAST scores with TEWL, a* and EI values was observed. The scores of questionnaire and LAST both negatively related to L* value.

CONCLUSION

Self-assessed questionnaire is associated with sensitive skin featured by oily and red face without impaired barrier function, whereas LAST is suitable to identify fragile skin barrier and enhanced blood flow on the face. Combination of both methods to diagnose sensitive skin might be more reliable.

The Association Between Short-Term Air Pollution Exposure and Post-Adolescent Acne: The Evidence from a Time Series Analysis in Xi'an, China

BACKGROUND

Post-adolescent acne is a common skin disease faced by adults. However, whether air pollution (AP) serves as a risk factor for post-adolescent acne remains elusive.

AIM

To determine the relationship between short-term AP exposure (within 7 days) and outpatient visits for post-adolescent acne.

METHODS

Daily outpatient visit data for post-adolescent acne and routinely AP data between 2010 and 2013 were collected from Xi'an, China. A generalized additive regression model was used to analyze the relationship between outpatient visits for post-adolescent acne and short-term ambient AP exposure. The gender-specific analyses were conducted as well.

RESULTS

Totally, 27,190 outpatient visits for post-adolescent acne were included. The results revealed that a 10 μg/m3 increase in PM10, SO2, and NO2 at lag 0-7 day was associated with the increase of outpatient visits for post-adolescent acne at 0.84% (95% CI: 0.53%, 1.16%), 1.61% (95% CI: 0.12%, 3.10%), and 3.50% (95% CI: 1.60%, 5.40%), respectively. The significant positive associations of PM10, SO2, and NO2 were found at both single-lag models and moving average models. The gender-specific analyses showed that the effect estimates of PM10 was stronger for females than for males, while there was no observed gender difference in the effects of SO2 and NO2.

CONCLUSION

Short-term exposure to AP was associated with increased outpatient visits for post-adolescent acne, especially for females in the effects of PM10.

Influence of family history, body mass index, selected dietary factors, personal habits, and menstrual history on oily skin in young women

BACKGROUND

Sebum secretion is affected by many internal and external factors.

OBJECTIVE

To identify risk factors in terms of family history, body mass index, selected dietary factors, personal habits, and menstrual history that may be associated with oily skin in young women.

PARTICIPANTS AND METHODS

We conducted a case-control study of young women aged 18-35 who came to Beijing Tongren Hospital for attending a health checkup. Cases were subjects with subjective skin type as oily skin. Control subjects were people with normal or dry skin. A standardized questionnaire on subjective skin type, family history of oily skin in first-degree relatives, menstrual history, personal habits, and selected dietary factors was administered to 540 subjects. Univariate and multivariate logistic regression analyses were performed for risk factors associated with oily skin.

RESULTS

A family history in first-degree relatives and a body mass index of more than 24 kg/m² were risk factors that increases likelihood of oily skin in young women (odds ratio 3.281, 95% confidence interval 2.204-4.882; odds ratio 1.677, 95% confidence interval 1.081-2.600, respectively). For those who consumed more than three servings of milk or sweets per week, the risk increased with the diet (odds ratio 1.634, 95% confidence interval 1.126-2.370; odds ratio 1.970, 95% confidence interval 1.034-3.754, respectively). There was no correlation between smoking, drinking alcohol, or menstrual variables and the risk of oily skin.

CONCLUSIONS

Family history, overweight and obesity, and a diet rich in milk or sweets are risk factors that increase likelihood of oily skin in young women. These findings may provide an opportunity to better guide skin care for patients.

The impact of air pollution on skin and related disorders: A comprehensive review

As the largest organ in the body, human skin is constantly exposed to harmful compounds existing in the surrounding environment as the first-line barrier. Studies have indicated that exposure to high concentrations of many environmental factors, such as ultraviolet (UV) radiation, outdoor air pollutants, including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), particulate matter (PM), heavy metals, gaseous pollutants, such as carbon monoxide (CO), nitric oxides (NO_x ), sulfur oxide (SO₂ ), ozone (O₃ ), and indoor air pollutants (solid fuels consumption), might interrupt the skin's normal barrier function. Besides, the intensity of the pollutants and the length of exposure might be a contributing factor. Air pollutants are believed to induce or exacerbate a range of skin conditions, such as aging, inflammatory diseases (atopic dermatitis, cellulitis, and psoriasis), acne, hair loss, and even skin cancers (mainly melanoma and Squamous Cell Carcinoma) through various mechanisms. The interaction between pollutants and the skin might differ based on each agent's particular characteristics. Also, damaging the skin barrier seems to be closely related to the increased production of reactive oxygen species (ROS), induction of oxidative stress, activation of aryl hydrocarbon receptor (AhR), and inflammatory cytokines. This article reviews recent studies on the correlation between air pollutants and skin diseases, along with related mechanisms.

Facial radiance influences facial attractiveness and affective impressions of faces

Objective

Facial attractiveness has been reported to be influenced by visual features such as facial shape and the colour and texture of the skin. However, no empirical studies have examined the effects of facial skin radiance on facial attractiveness. The present study investigated whether types of skin reflection (i.e. radiant, oily and shiny, and matte) and the position of the reflection on the face influence facial attractiveness and other affective impressions.

Methods

A total of 160 female participants (1) estimated the ages and (2) evaluated attractiveness and other impressions of unfamiliar female faces in a total of seven skin reflection conditions. These conditions incorporated three types of reflection (i.e. radiant, oily and shiny, and matte) and three positions of the reflection on the face (i.e. entire facial skin, only cheeks, and only T‐zone).

Results

The facial images of radiance on entire faces were rated as appearing younger than the facial images of oily shine on entire faces and the matte faces. Attractiveness ratings and other positive impressions increased in the order of the matte (ranked lowest), the oily shine on entire face, and the radiance on entire face (ranked highest) conditions. The reflection position also influenced facial attractiveness: attractiveness ratings and other positive impressions were higher in the radiance on entire face condition than in the radiant cheeks and the radiant T‐zone conditions. Interestingly, the radiant cheek faces were rated more radiant and healthier but less feminine and less bright than the radiant T‐zone faces.

Conclusion

These results suggest that facial radiance enhances facial attractiveness and conveys a wide variety of positive impressions on the observer. The magnitude of the effects of cheek radiance and T‐zone radiance differs across various affective impressions. Nevertheless, the results demonstrate that cheek and the T‐zone radiance both contribute to higher attractiveness and other positive impressions of the radiance on entire faces. We believe that our findings can contribute as a guide to the enhancement of positive facial impressions by means of skin radiance, thereby leading to a better understanding of the value of skincare and base makeup.

Variation of biophysical parameters of the skin with age, gender, and lifestyles

BACKGROUND

Sweet, spicy or greasy food, staying up late, and using electronic products for a long time are common bad habits nowadays. Their role in skin diseases has been paid much attention.

OBJECTIVE

The aim of this study was to investigate whether unhealthy lifestyles would affect the skin sebum content, SC hydration, and pH and how do they affect.

METHODS

A total of 300 volunteers were enrolled, and a multifunctional skin physiology monitor measured the three skin biophysical properties on the forehead and dorsal hand. Lifestyle factors were evaluated by a self-administered questionnaire.

RESULTS

Eating oily, sweet, spicy food, and staying up late increased the sebum content of the forehead significantly. Dorsal hand SC hydration was higher in people eating more sweet food and oily food, and forehead SC hydration was higher in people eating more sweet food and go to bed earlier. Eating sweet food could increase pH in both forehead and dorsal hand. The forehead pH decreased in using electronic products over 6 hours a day or staying up late. There are significant differences in sebum, hydration, and pH value among different age groups. In males, the pH was lower than females, but the sebum was higher.

CONCLUSION

Sebum content, SC hydration, and pH are affected by unhealthy lifestyles, age, and gender.

Quantitative measurement of skin surface oiliness and shine using differential polarized images

Excess amounts of skin surface oil can lead to adverse psychological consequences. Grease-spot photometry-based techniques measure sebum production rate. However, besides being tedious, these measurements are influenced by contact area, applied pressure, and time of application. Image analysis of polarized images has the potential to provide objective, quantitative information of skin oiliness. This study was designed to set up an imaging device for capturing and enhancing the changes in skin surface oiliness and to clinically and quantitatively, (via image analysis), evaluate varying levels of skin surface oiliness. Mineral oil was used to simulate skin surface oil. 40.5 µL of the mineral oil was applied within a two inch square area of interest on facial skin in twelve steps, from 1 to 40.5 µL, at 40% increments. The results indicate a strong correlation between the quantitative skin surface oiliness measurements and the clinical assessments. This sensitive technique has the potential to be utilized in future studies to evaluate product efficacies in reducing skin oiliness.

Comparative study into facial sebum level, pore size, and skin hydration between oily-skinned and dry-skinned Thai women

BACKGROUND

Subjective facial skin type is most frequently determined by the amount of sebum, which showed trends across subjective skin types in most previous studies while not in some. This study was conducted to evaluate the associations among subjective skin type, amount of sebum, stratum corneum hydration, and pore size in Thai women.

METHODS

Sixty-two healthy women with either self-described subjective oily or dry skin type were included and casual sebum level (CSL), sebum excretion rate (SER), clinical pore size score, mean pore area, and stratum corneum hydration were measured at several facial sites. Correlation coefficients between amount of sebum and other parameters were estimated.

RESULTS

Casual sebum level and sebum excretion rate were significantly higher in oily-skinned than dry-skinned group by 1.6-2.1 times. Mean pore area and clinical pore size score were not different between the 2 groups, nor did they correlate with CSL or SER. Corneometry was shown to be significantly higher in dry-skinned than oily-skinned group. Significant, negative correlations between corneometry and CSL were also found.

CONCLUSION

The subjective facial skin types were consistent with the amount of sebum, but not pore size or corneometry, among Thai women.

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

Background

Previous 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.

Objective

This 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.

Methods

A 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.

Results

Skin 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.

Conclusion

Women 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.

Optimizing the use of topical retinoids in Asian acne patients

Acne vulgaris is a common disease among people in Asia. International guidelines and treatment recommendations emphasize the central role of topical retinoids in the management of acne. However, topical retinoids remain underutilized in clinical practise, which may be in part due to fear of retinoid‐associated dermatitis/lack of experience, particularly in Asian patients. There is a perception that Asian skin has a greater tendency toward sensitivity compared with Caucasian skin. In our clinical experience, topical retinoid therapy can be used with excellent effect to treat Asians with acne. This article discusses available published work regarding the use of topical retinoids in Asian populations, and presents tips for utilizing these important agents in daily practise. Optimizing use of topical retinoids may improve adherence and, in turn, therapeutic outcomes and patient satisfaction.

Concealing a shiny facial skin appearance by an Aerogel-based formula. In vitro and in vivo studies

OBJECTIVE

To explore, in vitro and in vivo, the potential interest of an Aerogel-based formula, in concealing a naturally shiny facial skin.

METHODS

In vitro, various formulae and ingredients were applied as a thin film onto contrast plates and studied through measuring the shine induced following pump spraying of a mixture of oleic acid and mineral water as a sebum/sweat mix model. In such a test, an Aerogel ingredient led to very positive results. In vivo, two different formulae with various concentrations of Aerogel were randomly tested on half side of the face vs. bare side of Chinese women, under some provocative environmental conditions, known to enhance facial shine. These conditions comprised a normal activity under a hot and highly humid summer time followed - or not - by a hamam session. Both studies included comparative evaluations using a half-face procedure (treated/untreated or vehicle). In the first case, evaluations were quantitatively carried out, whereas the second one was based on a quantitative self-evaluations from standardized full-face photographs RESULTS: In vitro, the tested Aerogel, incorporated at 1% or 2% concentration in a common O/W cosmetic emulsion, shows an immediate light scattering effect, thereby masking shine. Such effect appears of much higher amplitude than that of two other tested particulate ingredients (Talc and Perlite). A noticeable remanence of anti-shine effect was confirmed in vivo in extreme conditions. The latter was self-perceived by all participants in the second study. This result is likely related to the super hydrophobic behaviour of the Aerogel.

CONCLUSION

As cosmetic ingredient, this new Aerogel appears as a highly promising ingredient for concealing the facial skin shine, a source of complaint from many consumers living in hot and humid regions.

The worldwide diversity of scalp seborrhoea, as daily experienced by seven human ethnic groups

OBJECTIVE

The re-greasing process and kinetics of the human scalp, post-shampooing, have been previously documented, in vivo, on a few Caucasian subjects. The objective of the presented research was to extend such knowledge over seven different ethnic groups.

METHODS

The post-shampooing re-greasing kinetics of the scalp was studied on 1325 subjects (women and men of two distinct age classes) from seven different ethnic groups in their residential and native country. Sebum amounts were determined onto small shaved scalp areas at various times post-shampooing, using the Sebumeter^® technique.

RESULTS

As previously published on Caucasian subjects, scalp re-greasing process follows a hyperbolic-like kinetics over days. However, amounts of collected sebum highly vary with ethnicity. As recorded through the casual level (CL) at the equilibrium phase, 2-3 days post-shampooing, the highest amount of sebum was found in African American subjects, followed in descending order by Caucasian American, Japanese, Chinese, Thai, Caucasian European and Indian subjects, the latter showing very low values. Lower amounts of sebum were recorded in the older age class in all ethnics, as compared to the younger one, and male subjects were found higher sebum producers than women, irrespective of ethnicity.

CONCLUSION

The kinetics and slopes of the re-greasing process of the human scalp appear similar in all ethnic groups studied. However, striking quantitative differences are found between the seven ethnic groups, resulting from different sebaceous production levels and scalp hygiene routines.

Pollution and acne: is there a link?

In recent years, the critical role that inflammation may play in the development and progression of acne has become increasingly recognized. The prevalence of acne is similar between Asian and Caucasian women, but Asian women have a higher prevalence of inflammatory acne. They also report their symptoms exacerbate during periods of high air pollution. The objective of this study was to review the current evidence that links air pollution to worsening of acne symptoms. Firstly, a group of five Asian and three European scientists with expertise in Dermatology reviewed the current literature and described current acne treatment practices in their countries. During this activity, they identified the need for further epidemiological and clinical research. Secondly, additional studies ensued which provided evidence that acne symptoms might exacerbate in regions of high ambient air pollution. Based on these findings, the authors suggest that people with acne should protect the natural barrier function of their skin with emollients and ultraviolet (UV)A/UVB protection.

Consequences of urban pollution upon skin status. A controlled study in Shanghai area

OBJECTIVE

After preliminary studies aimed at measuring pertinent biochemical parameters, potentially modified in subjects exposed to bad environmental conditions, a dedicated study was performed in Shanghai city to evaluate the effect of Urban pollution upon human skin and to collect feedback from the volunteers under study.

METHODS

This study was performed during summer 2008 in two different districts of Shanghai, on 159 local residents: 79 subjects from Xu Jia Hui (a centre Shanghainese area), more exposed to pollution, and 80 subjects from Chong Ming, an agricultural region closely located north of Shanghai (<100 kms) and less exposed to pollution, according to official data. Biochemical parameters were measured on skin, and feedback from volunteers was collected through a graduated 'Likert scale' questionnaire under a point scale (strongly agree, agree, disagree, strongly disagree and none).

RESULTS

The study demonstrated significant differences in several biochemical parameters measured in Chong Ming area, as compared to Urban area, with an increased ratio of squalene/lipids, a lower level of lactic acid and a better cohesion of stratum corneum. Both sebum excretion rate and sebum casual levels did not differ between the two districts. The volunteer's feedback evidenced a perceived link between pollution and their skin problems.

CONCLUSION

This study demonstrated a significant impact of the pollution upon the skin status, as illustrated by changes in superficial biochemical parameters and volunteers' perception.

Comparison of clinical and histological effects between lactobacillus-fermented Chamaecyparis obtusa and tea tree oil for the treatment of acne: an eight-week double-blind randomized controlled split-face study

BACKGROUND

Screening of natural compounds for the development of anti-acne therapeutic agents has been steadily required considering various side effects of acne medications. However, previous studies have mainly focused on experimental tests without clinical trials and histopathological analysis.

OBJECTIVES

To compare the clinical efficacy, safety and histopathological changes between Lactobacillus-fermented Chamaecyparis obtusa (LFCO) and existing tea tree oil (TTO).

METHODS

A total of 34 patients were instructed to apply 5% LFCO to the involved areas of a randomly allocated side and 5% TTO extract to the other side for 8 weeks in a double-blind split-face clinical trial.

RESULTS

After 8 weeks, inflammatory acne lesions were reduced by 65.3% on the LFCO side and by 38.2% on the TTO side. LFCO was also superior to TTO in the onset time of efficacy (p < 0.05). The LFCO side further demonstrated improvement for non-inflammatory lesions (52.6%, p < 0.05), decreased size of sebaceous glands and sebum output reductions. Patients' subjective satisfaction was also higher without severe adverse reactions. Protein expressions of nuclear factor κB decreased earlier on the LFCO side, and those of interleukin-1α (IL-1α), IL-8, insulin-like growth factor 1 receptor and sterol regulatory element-binding protein 1 decreased subsequently. Ultra-performance liquid chromatography/high-resolution mass spectrometry further demonstrated that the contents of dihydroxybenzoic acid, taxifolin and quercetin were increased in LFCO after fermentation.

CONCLUSIONS

LFCO treatment was rapid and effective for treating acne lesions compared to TTO. Histopathological findings correlated well with the clinical acne grade and treatment response. This novel natural compound appears to be effective and safe for acne treatment.

The seasonal variation in skin hydration, sebum, scaliness, brightness and elasticity in Korean females

BACKGROUND/PURPOSE

Age, gender, regional, and ethnic differences influence skin conditions. The purpose of this study was to observe the effects of environments, especially the air temperature, relative humidity, air pressure, duration of sunshine, and precipitation on skin, and the seasonal variation in skin hydration, sebum, scales, brightness, and elasticity in Korean females.

METHODS

The study included 89 Korean subjects, aged 29.7 ± 6.2 years. The five skin biophysical parameters (skin hydration, sebum, scales, brightness, and elasticity) were measured at six sites: forehead, under the eye, frontal cheek, crow's foot, lateral cheek, and inner forearm. Skin hydration was measured using the Corneometer® CM 825. Skin sebum was measured with Sebumeter® SM 815. Skin scaliness was measured with Visioscan® VC 98. Skin brightness (L* value) was measured by using Spectrophotometer. A suction chamber device, Cutometer® MPA 580, was used to measure the skin elasticity. The measurements were performed every month for 13 months, from April 2007 to April 2008.

RESULTS

There were significantly seasonal variations in environmental factors. The air temperature was the lowest in January (-1.7°C), and the highest in August (26.5°C). The relative humidity was the lowest in February (46%), and the highest in July and August (75%). There was a negative correlation between skin scaliness and three environmental factors such as air temperature, relative humidity, and highest precipitation. There was a positive correlation between skin scaliness and two environmental factors such as air pressure and duration of sunshine. Elasticity was correlated with air temperature positively and with air pressure negatively.

CONCLUSION

The correlations shown between the skin biophysical parameters and environmental factors demonstrate that the skin biophysical parameters are affected by environmental factors.

Characterization of Chinese body skin through in vivo instrument assessments, visual evaluations, and questionnaire: influences of body area, inter-generation, season, sex, and skin care habits

BACKGROUND/PURPOSE

The varying influence of multiple factors (e.g., aging, sex, season, skin care habits) on skin structure and function necessitates study within ethnic groups to fully characterize their skin.

METHODS

Men and women aged 40-50 years (n = 43) and their consanguineous same-sex children, aged 18-25 years (n = 43), living in Chengdu, China were enrolled in this single center, non-interventional study. Volunteers attended two study visits (summer, 2010 and winter, 2011) at which dermatologists measured transepidermal water loss (TEWL), skin hydration, sebum secretion, fine lines/roughness, melanin/erythema, temperature, and color, and clinically graded participants' skin. Participants answered a questionnaire, indicating their perceived skin type/condition. Data were analyzed using t-test/anova or Friedman/Wilcoxon test.

RESULTS

Objective measurements demonstrated statistically significant inter-generational differences in skin condition, with aged skin more wrinkled at most sites, having reduced oil/colder facial and décolletage skin, darker/more erythematous skin in exposed areas, and less hydrated/rougher heel skin; similarities were detected in skin melanin, erythema, and TEWL. There were also statistically significant differences between seasons and sexes. The intersection between instrument measurements and subjective perceptions of skin revealed notable differences.

CONCLUSION

Objective measurements and their intersection with subjective perceptions demonstrate the influences of inter-generation, season, sex, and living habits on Chinese body skin.

[Objective methods for analyzing outcomes in research studies on cosmetic dermatology]

Cosmetic dermatology is a field of medicine that is in constant development; therefore, the use of objective methods for validating the findings of scientific studies is crucial. The most commonly used techniques in the majority of these studies include histopathology, immunohistochemistry, morphometry, stereology, digital photography, biometry, optical profilometry and confocal microscopy. The objective of this review was to provide an update on the principal methods used as tools for analyzing outcomes and also to provide the dermatologist with means of sharpening his/her critical judgement with respect to the publications and presentations that use subjective evaluation methods.