Morphometric characteristics of feminine eyebrows: variations with ethnicities and age.

OBJECTIVE: To explore some morphological features of the eyebrows of women of different ethnicities and ages. MATERIALS AND METHODS: Standard digital photographs of 3600 women of six ethnicities, aged 18-84 years, previously used to describe the morphology of the human eyes, allowed us to focus on their eyebrows, as supplementary and opportunistic study. Photographs of both eyebrows were analysed partly by manual markings and automatically by dedicated algorithms. Six parameters of the eyebrows were recorded: length, waviness/curvature, oblique aspect, size (vertical height), total surface and hair coverage (density). RESULTS: Most criteria present ethnic specificities. These are: length (longer eyebrows of Indian, shorter among African women); waviness where the straighter eyebrows were found among Chinese and Japanese women. In general, the longer the eyebrows, the higher their waviness and vice versa. Thickness (or height) of the eyebrows presents a wide ethnic variability as well as hair coverage, where African women present the lower hair density, inversely to Indian women. The same holds true with regard to the total surface of eyebrows, of a large variability (by about four times). Some criteria appear more individually dependent than ethnic-specific, such as the oblique positioning, at the exception of Indian women with less oblique eyebrows. In all subjects, the criteria of both eyebrows (Left vs. Right) were found to be highly correlated (r > 0.7, P < 0.001). CONCLUSION: The present investigation brings new findings on a scarcely studied facial element, the morphologic features of which are, for most, ethnic-dependent. As applied consequences, the results of the present work pave the road to better adapt adorning procedures of the eyebrows vis-à-vis ethnic and age specificities.

OBJECTIF: D'explorer quelques critères morphologiques des sourcils de femmes de 6 ethnies, d'âges différents (18-84 ans). MÉTHODES: Des photographies digitales standards de 3600 femmes de 6 ethnies, âgées de 18 à 84 ans, préalablement utilisées pour décrire les morphologies des yeux, ont été mises à profit pour une analyse morphologique dédiée aux sourcils. Les images ont été analysées pour partie par marquages manuels, pour partie par des algorithmes de reconnaissance automatique. Six critères ont été analysés: longueur, ondulation, aspect oblique, taille (hauteur), surface totale et couverture pilaire (densité des poils). RÉSULTATS: Chez tous les sujets, les critères des deux sourcils (Gauche et Droit) ont été observés comme fortement corrélés, et présentent des spécificités ethniques pour la plupart. Par exemple, la longueur, i.e. plus élevée chez les femmes Indiennes, plus faibles chez les femmes Africaines, l'ondulation où les sourcils les plus droits sont trouvées chez les femmes Chinoises et Japonaises. En général, les plus longs sourcils présentent une plus forte ondulation et vice versa. Leur hauteur maximale présente aussi une forte dépendance ethnique tout comme la couverture pilaire où les femmes Africaines montrent une plus faible densité, à l'inverse des femmes Indiennes. Un même résultat est obtenu pour la surface totale qui présente de fortes variations inter-ethniques, allant du simple au quadruple. D'autres paramètres semblent plus individuels qu'ethniques tel que l'aspect oblique, à l'exception des femmes Indiennes qui présentent les sourcils les moins obliques. CONCLUSION: Cette investigation apporte quelques nouveaux résultats sur un sujet très peu étudié, dont la morphologie est, sur de nombreux aspects, ethnique-dépendante. Ces résultats offrent alors, en terme d'application, une approche plus adaptée des procédures d'ornementation des sourcils vis à vis des spécificités ethniques et de l'âge.

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.

The colour of the human skin: fruitful science, unsuitable wordings.

A review of the various facets of the colour of human skin is proposed. It aims first at illustrating the paradoxical association of the remarkable recent scientific advances that characterize changes in the skin colour, with some totally inappropriate or outdated phrasings used in its communication. As a second objective, it aims at proposing an alternative to these wordings. The latter would combine six shade types, defined by Individual Type Angle (ITA) values, a coloured reference chart and associated colour adjectives, highly corresponding to the six Phototypes previously defined by Fitzpatrick. Such alternative would overcome most references to both ethnic- and ethical-related issues.

[Place your bets, the die is cast ... the skin at the retiring age today and tomorrow]. / Faites vos jeux, rien ne va plus ... la peau à l'age de la retraite, aujourd'hui et demain.

Senescence of people represents a global expression of obsolescence of their organs, tissues, cells and constitutive molecules. Skin, similarly to any other organ, is ageing in particular ways. Over the past century, the time effects on skin have been expressed differently. Skin of any individual presently engaged in the Third Age looks different from that of his/her line ancestral. What is the expected future? The Third Age population is expanding and skin problems call for a variety of management procedures. Prevention of the diverse types of skin ageing has made tremendous progresses particularly in the field of preventive and corrective dermocosmetology. The future should further speed up such trends.

[Striae distensae, colors and mechanobiology]. / Les vergetures, leurs couleurs et leur mécanobiologie.

Striae distensae represent a common skin condition, corresponding to a physiological event particularly developed during adolescence, pregnancy and gain in body weight. In addition, these lesions are induced by the Cushing syndrome or an intense corticotherapy. The viscoelastic properties of the skin are altered and vary according to the severity of striae distensae. Otherwise, the colours of striae distensae vary with time in response to the mechanobiology of blood vessels and melanocytes.

A preliminary investigation of the impact of oily skin on quality of life and concordance of self-perceived skin oiliness and skin surface lipids (sebum).

OBJECTIVE: This preliminary study investigated both the impact of oily skin on quality of life (QoL) and the agreement between subjective oily skin self-assessment and objective skin surface sebum measurement in young to middle-aged Chinese women in Beijing. METHODS: A 18-item Chinese version of the Oily Skin Self-Image Questionnaire (OSSIQ) was used to assess the impact of oily skin on QoL in 300 healthy female subjects (age groups: 20-25; 26-30; 31-35,). The subjects were divided equally into the oily skin group and the non-oily skin group based on their self-perception of skin oiliness. The level of skin surface lipids (SSL) was measured on the middle of the forehead, and both cheeks using the Sebumeter(®). In order to assess the agreement between self-perceived skin oiliness and measured SSL, we tentatively used the SSL median value as a dividing point to regroup all subjects. RESULTS: The results indicate that the Chinese version of the OSSIQ distinguished the oily skin group from the non-oily skin group. Subjects in the oily skin group had significant higher emotional status score and behavior score when compared with subjects in the non-oily skin group. Subjects in the oily skin group had higher SSL when compared with subjects in the non-oily skin group, especially in younger age groups. The agreement between self-perceived skin oiliness and measured SSL was moderately strong in younger age groups, and declined with age. CONCLUSION: These results strongly suggest that having oily skin can cause a significant negative impact on QoL among Chinese women. The Chinese version of the OSSIQ is a reliable and valid tool for assessing the impact of oily skin on QoL. The accuracy of oily skin self-assessment declines with age.

'Cosmeceuticals'. Of men, science and laws .

Through the hybrid term 'Cosmeceuticals', the present paper aims at reviewing some scientific and legal sources of ambiguities or uncertainties that, in many regulatory cases, added confusions to the respective roles of drugs and cosmetics. The origins of such questions, likely arose from new anti-ageing claims from the cosmetic industry in the late 80s which faced a rather old regulatory backdrop. Based on the analysis of some legal statements and scientific facts from a 2012 vision, this review tentatively aims at re-defining the respective roles of these two branches that both fill the two vital needs of humans, 'being' and 'well-being'.

Relationships between hair growth rate and morphological parameters of human straight hair: a same law above ethnical origins?

After measurement of individual growth rates, natural hair fibres from Asian and Caucasian subjects were analysed using scanning electron microscopy. In total, more than 1000 hairs were analysed. Measurements of diameter, medulla and interscale distance (average distance between two successive cuticle scales) show these parameters strongly correlated with hair growth rate. A thicker hair fibre corresponds to a faster growth rate, a shorter interscale distance and greater probability to have a medulla, and vice versa, a thin hair fibre shows slower growth rate, a larger interscale distance and a lower probability to have a medulla. Very interestingly, this finding appears to be unrelated to the ethnic origin of the subjects, suggesting a common characteristic of human hair, at least for the straight or semi-straight hair studied. From a practical viewpoint, this finding clearly suggests an alternative method for measuring hair growth rates, by measuring the interscale distance, which appears easier than using common laboratory equipments.

Challenging the scalp with 'dry' wash shampooing (DW) on Chinese men: an in vivo study.

Cosmetic habits show a strong diversity worldwide. The same applies to procedures that are considered as basic hygiene acts such as shampooing. Apart from common traditional shampoo routine, a special shampoo procedure, 'dry' wash is daily performed in Chinese hair salons. Without pre-wetting step, hairdresser applies the shampoo directly to dry hair with small quantity of water to create foam. Hand massaging is then offered on the scalp. This shampooing process is distinguished from traditional 'regular wash' by slightly diluted shampoo, and longer contact with the scalp and scalp massaging, all of which could be possibly considered as challenges to the structure and barrier function of the scalp. In this study, the effects of 'dry' wash on Chinese scalp have been investigated, in vivo, using regular wash as a control. A total of 67 Chinese males in two cohorts, non-dandruff and with dandruff, were included. In each cohort, volunteers were split into two groups, one with 'dry' wash and the other one with regular wash. Both shampoo methods were performed daily for five consecutive days using the same shampoo formulation. Volunteers' self assessment, clinical assessment by an expert and instrumental measurements were carried out. The results showed that Chinese 'dry' wash did not induce any negative consequence on the scalp physiology under such experimental conditions.

Chronological ageing of human hair keratin fibres.

Examination of very long hair (length > 2.4 m) using a large range of evaluation methods including physical, chemical, biochemical and microscopic techniques has enabled to attain a detailed understanding of natural ageing of human hair keratin fibres. Scrutinizing hair that has undergone little or no oxidative aggression--because of the absence of action of chemical agents such as bleaching or dyeing--from the root to the tip shows the deterioration process, which gradually takes place from the outside to the inside of the hair shaft: first, a progressive abrasion of the cuticle, whilst the cortex structure remains unaltered, is evidenced along a length of roughly 1 m onwards together with constant shine, hydrophobicity and friction characteristics. Further along the fibre, a significant damage to cuticle scales occurs, which correlates well with ceramides and 18-Methyl Eicosanoic Acid (18-MEA) decline, and progressive decrease in keratin-associated protein content. Most physical descriptors of mechanical and optical properties decay significantly. This detailed description of natural ageing of human hair fibres by a fine analysis of hair components and physical parameters in relationship with cosmetic characteristics provides a time-dependent 'damage scale' of human hair, which may help in designing new targeted hair care formulations.

Reversal effects of topical retinoic acid on the skin of kidney transplant recipients under systemic corticotherapy.

The systemic long-term corticosteroid treatment administered to kidney graft recipients (KGR) within the framework of the required immunosuppressive therapy induces an atrophy of the skin, from the sixth month onwards. We studied the effect of topical all-trans retinoic acid (0.05%; Galderma Labs.) applied to the forearms of 27 KGR (14 men, 13 women) over a 6-month period. Twenty-four subjects completed the trial. The following results were obtained in the treated forearm versus the untreated forearm (excipient alone): clinically, an increase in skin thickness; by noninvasive techniques, an increase in skin thickness, skin elasticity, skin conductance, and TEWL, and a reduction in the size of the corneocytes. No change in stratum corneum lipid content was observed. A sex-related difference was noted in the response to treatment under our experimental conditions, the female patients responding better. A punch biopsy (4 mm) was performed on both forearms of four patients after the 6-month period. Histologic and ultrastructural examination revealed epidermal and dermal changes evoking increased cellular metabolism in the retinoic acid-treated forearms.

The lipometre: an easy tool for rapid quantitation of skin surface lipids (SSL) in man.

The purpose of this study is to present a rapid, simple, and accurate method for quantitation of SSL in man. The technique which is derived from the works by Schaefer and Kuhn-Bussius, employs a series of clearn ground glass plates, and an apparatus, the Lipometre, for the determination of the variation of light transmission across the plates as a function of the fat deposited on them. Results on 32 adults, males and females, show that the first four iterative samplings, at constant pressure, on the same forehead area follow an identical physical law independently of whether the skin is fatty or dry. This law affords a precise definition of the Casual-Level, its quantification and its correlation with skin patterns. It is consequently possible, either as an investigative or a routine technique, to predict the total amount of SSL with good accuracy within 2 min. The SSL, for non-pathological skins, fall within the range 150 microgram/cm2 to 900 microgram/cm2 which is in good agreement with values quoted in the literature.

An original procedure for quantitation of cutaneous resorption of sebum.

This paper describes an original in vivo device to investigate and quantify cutaneous resorption of sebum. Such a phenomenon was explored using a photometric determination of residual skin surface lipids at different times following initial deposits of known amounts of artificial sebum on demarcated areas. The technique was carried out on seven healthy subjects. The chosen area was the anterior aspect of the forearm, owing to the very low sebum production of this site, less than the sensitivity of the measuring instrument. The kinetics of absorption of applied sebum turned out to be hyperbolic-like and well correlated with experimental results (r = 0.992), allowing a mathematical determination of the initial velocity of penetration of sebum into the skin, reaching 20 micrograms/cm2.min for a standard program including a mean initial deposit of 116 micrograms/cm2. This kinetics actually does not fit with a true percutaneous absorption of lipids but is compatible with that of absorption into the stratum corneum. It conveys the faster absorption of the latter for sebum, a well-known but not so far quantified property of stratum corneum. The model here described is not at once transposable to skin areas with high sebum production since, quite obviously in such zones, the stratum corneum is permanently saturated with skin surface lipids. Therefore, the conclusions of this work cannot be correlated with the regreasing parameters studied so far on the forehead, but they provide interesting data about the evolution of sebum following its output onto the skin surface and therefore a better understanding of sebaceous physiology.

Effect of topical corticosteroids on human sebum production assessed by two different methods.

Topical corticosteroids are widely used in cutaneous diseases. Although their mode of action on different skin compartments has been documented, little is known about their effects on the human sebaceous gland. We investigated the effects of two corticosteroids of differing potency on the excretion of sebum by means of two validated techniques: the Sebutape and the Lipometre. This study was conducted on the forehead skin of normal healthy subjects. The results obtained with both techniques correlated well. The application of both corticosteroids during a 4-week period led to a significant decrease in sebum excretion. This decrease was more pronounced with the more potent corticosteroid (Dermovate). In the light of these findings, it is likely that topical corticosteroids exert an anti-proliferative action upon the sebaceous cells in a similar manner to their effect in other skin compartments.

Effect of residence time on the efficacy of antidandruff shampoos.

Dandruff is known to be controlled by fungistatic shampoos active against Malassezia spp. These products also remove the loosely attached scales. This study was performed to assess the effect of a 5-min residence time on the efficacy of antidandruff shampoos. Two commercially available shampoos were used in two groups of 21 panelists with severe dandruff. They contained either 1% ketoconazole or 1% piroctone olamine. In each group, intraindividual comparisons were made by a split-scalp design between the effect of a 5-min residence time versus no residence time. Both shampoos induced significant reductions in scaliness and yeast colonization. The beneficial effects were obvious immediately after one single shampooing and 3 days later as well. The improvement was greater with a 5-min residence time. The piroctone olamine treatment benefited more than the ketoconazole treatment from the extension of shampoo-exposure time. In conclusion, the benefit of a residence time in treating dandruff is documented. The level of improvement in efficacy may vary according to the nature of the shampoo.

The hair eclipse phenomenon: sharpening the focus on the hair cycle chronobiology.

Chronobiology governing the hair cycle is a fascinating and complex process. Both the hair growth cycle and the hair shaft growth are coordinated and depend on the interplay of different biological signals and various exogenous stimuli. A latency period may occur between hair shedding (teloptosis, exogen phase) and the early emergence of the next anagen VI stage. This lag time referred to on the hair eclipse phenomenon likely depends on the influence of a series of distinct synchronizers, and does not represent per se a peculiar hair cycle phase. It is the result of some dysregulations of the hair cycling, involving early teloptosis, delayed anagen I initiation or stunted hair growth at any stage between the anagen I and anagen V phases. As such, the hair eclipse phenomenon may be an erratic process occurring in physiopathological conditions affecting hair follicles singly or in focal to generalized patterns. It may be more frequent when it follows synchronized teloptosis occurring in telogen effluvium (newborn alopecia, post-partum alopecia, seasonal alopecia and alopecia areata). It may also be prominent when microinflammation is abutted on the permanent portion of the hair follicle as in dandruff, seborrhoeic dermatitis, androgenic alopecia and photoageing baldness. Local synchronizers such as growth factors and other mediators may eventually be lacking or involved in the hair eclipse phenomenon. Their identification and characterization might drive new corrective or preventive applications.

[The history of dandruff and dandruff in history. A homage to Raymond Sabouraud]. / Histoire des pellicules et pellicules de l'histoire. Un hommage à Raymond Sabouraud.

In one of his books, written at the beginning of this century, Raymond Sabouraud devotes some 280 pages to the history of dandruff. Their reading illustrates how, from the Greeks to Sabouraud's era, this desquamative disease has been subjected to endless doctrinal and scientific conflicts, long before the so-called "present" controversies. One of the early conflicts, between Celsus and Galen, lies in the nature of the squames, i. e. dry or exudating, leading to the inclusion (or non inclusion) or pityriasis in the group of desquamative diseases, such as psoriasis or ichytosis. Translated into Latin (furfur, porrigo) and into Arabic, the word pityriasis was replaced in the Middle Age by tinea which then referred to any disease of the human scalp. With Plenk, Lorry, Willan and others, the 18th century brought a new attitude of mind where observation took precedence over doctrine, but owing to the lack of experimental approach there was no adequate description of the squames and their anatomical origin. This was the case with Hebra who, in the 19th century, claimed that dandruff was nothing but a sebaceous disease. This major turn resulted for decades in a confusion between dandruff and seborrhoea. In the late 19th century, bacteriological studies were decisive steps taken by Rivolta, Malassez and Sabouraud. The presence on scalps affected with dandruff of a bottle-shaped "fungus" (Pityrosporum ovale was initially not regarded as a yeast) was taken as being the definite cause of the disease. The Sabouraud dogma was born, but as early as 1877 it was denied by Vidal who observed these "spores" on healthy scalps.(ABSTRACT TRUNCATED AT 250 WORDS)

[Physiology of the pilosebaceous follicle]. / Physiologie du follicule pilo-sébacé.

The human pilosebaceous follicle shows an extreme diversity with regard both its variation according to its localisation along the human body, and the various physiological dependences of the two tissues which comprise the pilosebaceous follicle. These latter, highly differentiated toward specialised synthesis (proteins, lipids) have their own specific physiology which, though, responds to some common mediators. Each pilosebaceous follicle shows specific cycles and regulation, irrespective with those of its "neighbour". Despite such a complex situation, the most common features of these two tissues, as well as their endogenous and exogenous consequences, are described.