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The male beard hair and facial skin - Challenges for shaving
Abstract
The challenge of shaving is to cut the beard hair as closely as possible to the skin without unwanted effects on the skin. To achieve this requires the understanding of beard hair and male facial skin biology as both, the beard hair and the male facial skin, contribute to the difficulties in obtaining an effective shave without shaving-induced skin irritation. Little information is available on the biology of beard hairs and beard hair follicles. We know that, in beard hairs, the density, thickness, stiffness, as well as the rates of elliptical shape and low emerging angle, are high and highly heterogeneous. All of this makes it challenging to cut it, and shaving techniques commonly employed to overcome these challenges include shaving with increased pressure and multiple stroke shaving, which increase the probability and extent of shaving-induced skin irritation. Several features of male facial skin pose problems to a perfect shave. The male facial skin is heterogeneous in morphology and roughness, and male skin has a tendency to heal slower and to develop hyperinflammatory pigmentation. In addition, many males exhibit sensitive skin, with the face most often affected. Finally, the hair follicle is a sensory organ, and the perifollicular skin is highly responsive to external signals including mechanical and thermal stimulation. Perifollicular skin is rich in vasculature, innervation and cells of the innate and adaptive immune system. This makes perifollicular skin a highly responsive and inflammatory system, especially in individuals with sensitive skin. Activation of this system, by shaving, can result in shaving-induced skin irritation. Techniques commonly employed to avoid shaving-induced skin irritation include shaving with less pressure, pre- and post-shave skin treatment and to stop shaving altogether. Recent advances in shaving technology have addressed some but not all of these issues. A better understanding of beard hairs, beard hair follicles and male facial skin is needed to develop novel and better approaches to overcome the challenge of shaving. This article covers what is known about the physical properties of beard hairs and skin and why those present a challenge for blade and electric shaving, respectively. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.
... This corroborates common self-reported signs of shaving dermatitis and PFB. 32 Distinct anatomical sites were investigated, evaluating the spatial variability in skin response to shaving. At baseline, the magnitude of values for the vessel diameter and vessel density were smaller on the forearm than on the cheek/neck. ...
... It has been hypothesised that shaving-induced skin irritation is most likely a result of mechanically induced neurogenic inflammation with reflex hyperaemia, which may be caused by microtrauma. 32 Our study corroborates this hypothesis with distinct changes in microvascular parameters measured using dynamic OCT. However, further research is needed to elicit its relationship to inflammatory markers, which could include the use of non-invasive biofluids from the skin surface. ...
... Reportedly, the neck skin is rougher than the cheek and the hair has a lower emerging angle. 32 These factors may contribute to the stimulus introduced in the present study where participants were requested to shave in a small area for 60 s There may also be differences in the pre-conditioning of these skin sites, with cheek skin exposed to environmental challenges (UV, wind, rain) more frequently than the neck site. This may alter the tolerance to external stimuli. ...
Background
Consumer products such as electrical shavers exert a combination of dynamic loading in the form of pressure and shear on the skin. This mechanical stimulus can lead to discomfort and skin tissue responses characterised as “Skin Sensitivity”. To minimise discomfort following shaving, there is a need to establish specific stimulus‐response relationships using advanced tools such as optical coherence tomography (OCT).
Objective
To explore the spatial and temporal changes in skin morphology and microvascular function following an electrical shaving stimulus.
Methods
Ten healthy male volunteers were recruited. The study included a 60‐s electrical shaving stimulus on the forearm, cheek and neck. Skin parameters were recorded at baseline, 20 min post stimulus and 24 h post stimulus. Structural and dynamic skin parameters were estimated using OCT, while transepidermal water loss (TEWL) was recorded to provide reference values for skin barrier function.
Results
At baseline, six of the eight parameters revealed statistically significant differences between the forearm and the facial sites, while only surface roughness (Rq) and reflectivity were statistically different (p < 0.05) between the cheek and neck. At 20 min post shaving, there was a significant increase in the TEWL values accompanied by increased blood perfusion, with varying magnitude of change dependent on the anatomical site. Recovery characteristics were observed 24 h post stimulus with most parameters returning to basal values, highlighting the transient influence of the stimulus.
Conclusions
OCT parameters revealed spatial and temporal differences in the skin tissue response to electrical shaving. This approach could inform shaver design and prevent skin sensitivity.
... It is elliptical with a diameter twice larger and 1,000 times stiffer than the scalp follicle. Compared to the adult scalp's density of 615 follicles per cm 2 , the beard density contains between 20 and 89 follicles per cm 2 [7]. All beard hairs contain a medulla, though there are some ethnic varia-tions: for example, blond and grey hairs lack medullae and significant melanocytes in the outer root sheath and bulb regions [8,9]. ...
... These nonmedullary proteins have been implicated in antigen reactivity [10] following a breakdown of the HFIP [11][12][13]. Some phenotypic ethnic differences include a denser network of hair follicles around the mouth in Asian men [7], and a companion layer mutation in the k6hf gene that can increase by 6-fold the onset of chronic inflammatory conditions like pseudo-folliculitis barbae in African-American men [14,15]. ...
... The ALBAS tool shows that the neck region was most affected, having a median score of 6.8/10 followed by the left and right beard regions (combined median score of 5.2/10) [40]. This finding corroborates with findings in other studies that showed the neck and beard sides to be the most visibly affected by BAA [7,30,36]. ...
Beard alopecia areata, or alopecia areata barbae, (BAA) is a subset of alopecia areata, a T-cell mediated inflammatory disease that disrupts the hair follicle cycle leading to early onset of catagen. The aim of this review is to help strengthen clinicians' skills in the evaluation, diagnosis, and management of BAA. We performed a literature review according to the modified PRISMA guidelines, using a combination of relevant key words in electronic databases. According to the data from the 25 articles on BAA reviewed here, BAA mostly affects middle-aged men (mean age 31 years) who typically experience patchy hair loss in the neck region, which spreads to the scalp within 12 months. Similar to AA, BAA is associated with autoimmune diseases such as H. pylori and thyroiditis; however, BAA has no clear genetic pattern of inheritance which is observed in alopecia areata. Common dermoscopic findings in BAA include vellus white hairs and exclamation mark hairs, which may help distinguish it from other pathologies affecting facial hair. In clinical trials, the ALBAS tool offers clinicians an objective metric to evaluate BAA severity. Until recently, topical steroids have been the mainstay therapy; however, topical and oral janus kinase inhibitors are achieving improved results, with up to 75% beard regrowth in an average of 12 months.
... Indeed, using RCM, the depth at which cells still form a 'honeycomb' structure is reportedly indicative of high skin sensitivity. 48 Other factors such as tissue stiffness and surface roughness represent parameters implicated in the assessment of skin sensitivity 49 although, to date, they have not been studied in-depth. In addition, an assessment of vascular density may reflect skin sensitivity. ...
... Erythema or redness of skin has regularly been recognised as a key indicator in the clinical presentation of SS, 32 as well as with mechanical irritation of skin, such as shaving. 49,52 However, the perception of skin colour and redness is highly subjective in nature. 53 This has motivated the development of reliable and reproducible methods to provide an objective evaluation of skin colour. ...
... 65 Specifically, physical irritation of the skin is known to induce an inflammatory response with local hyperaemia. 49 Historically, the assessment of inflammatory skin reactions has largely relied on invasive techniques, such as biopsies, and visual assessment meth- ...
Background
Skin sensitivity (SS) is a commonly occurring response to a range of stimuli, including environmental conditions (e.g., sun exposure), chemical irritants (e.g., soaps and cosmetics), and mechanical forces (e.g., while shaving). From both industry and academia, many efforts have been taken to quantify the characteristics of SS in a standardised manner, but the study is hindered by the lack of an objective definition.
Methods
A review of the scientific literature regarding different parameters attributed to the loss of skin integrity and linked with exhibition of SS was conducted. Articles included were screened for mechanical stimulation of the skin, with objective quantification of tissue responses using biophysical or imaging techniques. Additionally, studies where cohorts of SS and non‐SS individuals were reported have been critiqued.
Results
The findings identified that the structure and function of the stratum corneum and its effective barrier properties are closely associated with SS. Thus, an array of skin tissue responses has been selected for characterization of SS due to mechanical stimuli, including: transepidermal water loss, hydration, redness, temperature, and sebum index. Additionally, certain imaging tools allow quantification of the superficial skin layers, providing structural characteristics underlying SS.
Conclusion
This review proposes a multimodal approach for identification of SS, providing a means to characterise skin tissue responses objectively. Optical coherence tomography (OCT) has been suggested as a suitable tool for dermatological research with clinical applications. Such an approach would enhance the knowledge underlying the multifactorial nature of SS and aid the development of personalised solutions in medical and consumer devices.
... Suboptimal shaving may trigger vasodilation in the small blood vessels within the dermis, resulting in hyperemia and erythema. 1,2 This condition is known as "razor burn", or shaving-induced erythema. This can, in turn, provoke a significant inflammatory response in the skin. ...
... The complexity of shaving is further compounded by the anatomy of male facial hair (e.g., diversity in thickness, length, stiffness, and density, along with an oblique angle of growth) and skin (e.g., heterogeneous morphology, roughness, slower healing properties, and susceptibility to hyperpigmentation). 2 Shaving razors must delicately manage forces applied to skin and hair, necessitating thoughtful blade design. ...
Background
While shaving‐induced erythema is a common inflammatory skin issue, there is a lack of quantitative information on how well a shaving product performs in this regard. In this study, multispectral near‐infrared spectroscopy (NIRS) imaging was used to quantitatively and qualitatively measure the extent of shaving‐induced erythema. The research compares a safety razor and a cartridge razor to evaluate their impact on skin irritation.
Materials and methods
Fifty‐nine healthy male volunteers without pre‐existing skin conditions were enrolled. Basic demographics were recorded, and participants' faces or necks were imaged before shaving. Shaving was conducted on the right side of the face/neck with the safety razor and on the left side of the face/neck using the 3‐blade cartridge razor. Images were captured immediately after shaving, at 5 and 10 min post‐shaving.
Results
Tissue oxygen saturation (StO2) measurements demonstrated that the safety razor induced significantly less erythema than the cartridge razor. Immediately after shaving, 40.3% of skin shaved with the safety razor had erythema compared to 57.6% for the cartridge razor. At 5 min post‐shaving, 36.5% of skin shaved with the safety razor had erythema, compared to 53.8% of cartridge razor.
Conclusions
Multispectral NIRS revealed significant differences in shaving‐induced erythema between safety and cartridge razors. Safety razors demonstrated a lower incidence of erythema, suggesting a potential advantage for individuals prone to skin irritation. This study contributes valuable insights into skin irritation and highlights the potential of multispectral NIRS in dermatology research.
... Viena dažniausių vyrų odos būklės problemų -odos sudirgimas po skutimosi [7]. Išaugus veido odos drėkinimo poreikiui, vyrų odos priežiūros priemonių rinkoje atsirado drėkinamieji kremai po skutimosi [4,7,5]. ...
... Viena dažniausių vyrų odos būklės problemų -odos sudirgimas po skutimosi [7]. Išaugus veido odos drėkinimo poreikiui, vyrų odos priežiūros priemonių rinkoje atsirado drėkinamieji kremai po skutimosi [4,7,5]. ...
Vakarų visuomenėje vyrams skirtų veido odos priežiūros produktų rinkos plėtojimas yra svarbus poslinkis, siekiant didesnio vyrų dėmesio kūno gražinimui, veido odos puoselėjimui, akcentuojant „sėkmingo senėjimo“ idėją. Kintant vyrų odos priežiūros įpročiams, didėja vyrams skirtų kosmetikos priemonių vartojimas ir poreikis, tačiau vyrų kosmetikos rinka vis dar nėra pakankamai išvystyta. Skutimasis daugeliui vyrų buvo ir tebėra vienintelė kasdienė veido odos priežiūros procedūra, o senėjimą stabdančioms kosmetikos priemonėms nuo raukšlių dėmesys nėra pakankamas. Darbo tikslas − įvertinti vyrų veido odos kosmetologinės priežiūros įpročius ir motyvaciją lemiančius veiksnius. Metodika. Atliktas kiekybinis tyrimas: anoniminė internetinė apklausa. Apklausoje dalyvavo Klaipėdos apskrityje gyvenantys 354 vyrai, nuo 18 iki 65 metų, amžiaus vidurkis – 26,66±8,77 metų. Tiriamuosius motyvuojantys veiksniai vertinti 5 balų Likerto skalėje. Nustatytas klausimų patikimumas: Cronbach alfa koeficientas lygus 0,7. Statistinė duomenų analizė atlikta naudojant SPSS 26 programinį paketą. Taikytas Kolmogorov-Smirnov, Mann-Whitney U, Kruskal-Wallis H testai, Spearman koreliacijos koeficientas. Skirtumai tarp lyginamų grupių ar požymių laikyti statistiškai reikšmingais, kai p≤0,05. Išvados. Daugiau nei pusė apklausoje dalyvavusių Klaipėdos apskrities vyrų naudoja veido odos kosmetines priežiūros priemones, dažniau − vyresnio amžiaus asmenys. Ženkliai mažesnė tiriamųjų dalis naudojasi profesionalių kosmetologių atliekamomis veido priežiūros procedūromis grožio salonuose. Jaunesnio amžiaus vyrų, gyvenančių miestuose, tarp veido odos priežiūros motyvaciją lemiančių veiksnių dominuoja siekis išvengti odos estetinių problemų ir būti patraukliu. Auganti vyrų odos priežiūros priemonių rinka rodo didėjantį vyrų susidomėjimą veido odos ir viso kūno senėjimo problemomis ir sveikos jaunatviškos išvaizdos išsaugojimu. Odos priežiūra turėtų būti suprantama kaip bendrosios sveikatos dalis. Holistinis rūpinimasis savo sveikata, šalinant senėjimo veiksnius, teikia vilties, kad ateities vyrų kartos odos priežiūrą laikys ne tik grožio, bet ir sveikatos stiprinimo priemone.
... Skóra mężczyzny posiada mniej włókien elastycznych, co skutkuje tym, że zazwyczaj występują u nich większe i głębsze zmarszczki. Skóra mężczyzn jest również obciążona większą ilością grubszych włosów, a ponadto dzięki swej grubości nie jest zbyt wrażliwa, natomiast cieńsza i delikatniejsza skóra kobiet jest mniej odporna na urazy i kosmetyki o wyższym pH oraz częściej jest narażona na podrażnienia (Draelos, 2012;Maurer et al., 2016). Zatem mężczyźni powinni stosować więcej kosmetyków przeciwstarzeniowych i przeciwzmarszczkowych oraz wspomagających usuwanie zarostu i łagodzenie podrażnień po jego usunięciu, a kobiety powinny wybierać kosmetyki odżywcze i regenerujące (Cowley and Vanoosthuyze, 2012;Nolan and Marmur, 2012;Li et al., 2022). ...
Purpose: The aim of the study was to verify the opinion of women and men of different ages about face care, as well as the use of face care cosmetics and care possibilities. Methodology. A total of 160 respondents took part in the study. The level of knowledge concerning the principles of proper skin care, facial skin care related to skin problems, as well as knowledge of the methods and cosmetics used for this purpose were tested. Among the respondents took part 80 women (50 %) and 80 men (50 %), aged 17 to 64 years old. Most of the respondents were those surveyed aged between 20 and 30, with 36 women (22.5 % of all respondents) and 29 men (over 18 % of all respondents). The second largest group is those surveyed between the ages of 30 and 40; in this group, there were 15 women (over 9 % of all respondents) and 21 men (over 13 % of all respondents). The remaining groups are as follows: under 20 – 22 people (almost 14 %), between 40 and 50 – 26 people (over 16 % of respondents), and over 50 – 11 people (less than 7 % of respondents). Together with the survey, the respondents received information about its author, purposefulness, and anonymity of the survey. The survey, which is a research tool, is its own development. The study consisted of answering the survey questions independently without the participation of the researcher. The survey consisted of 11 different types of questions that were designed to motivate the respondents to provide the information sought. These were both metric questions and questions about the subjective experiences of the respondents. Scientific novelty. Almost 40 % of the respondents believe that face care is for them the use of cosmetics for this purpose. Not much more than 30 % of all respondents claim that showering is face care. The answer "make-up removal" was given by over 16 % of all respondents, and "treatments in a beauty salon" was 13.5 %. On the other hand, 2.19 % of respondents answered that they could not assess what facial care meant to them. When examining the frequency of using cosmetics by the respondents, over 50 % of the respondents claim that they use them every day, about 45 % – sometimes, and only 2.5 % do not use them at all. Creams, lotions, tonics, and facial cleansing gels are the most popular cosmetics used for facial skin care. On the other hand, men most often use soap for facial skin care, and women – micellar water. More than half of the respondents declare that they use peels (almost 80% of women surveyed, almost 20 % of men). More than half of the respondents answered that they use a mask; they were mostly women, who were dominated by cleansing and moisturizing masks. The survey also asked about cosmetics eliminating imperfections, where moisturizing and anti-acne cosmetics dominated in both sexes. Conclusions. This study demonstrated that еhe respondents' knowledge of facial care is definitely unsatisfactory. When choosing face care cosmetics, respondents are most often guided by the price and intended use for their skin type. On the other hand, taking into account the division into sex and age, it is rather women who take into account these factors and often pay attention to the composition and brand of the cosmetic. On the other hand, men are very often guided by price, brand, and efficiency, especially at a young age, while later age they are more interested in the convenience of use and the opinion of others. Men are just as often guided by habit. Therefore, it can be concluded that they forget about the most important values of cosmetics.
... Effective shaving is technically challenging, as it requires the robust removal of stiff terminal hairs, whilst minimizing collateral damage to the underlying skin substrate (6). Poor-quality shaving can cause nicks, cuts and a significant inflammatory response, mediated by the high concentration of immune cells, blood vessels and nerve endings within the perifollicular skin (7). In the face of barrier damage, pro-inflammatory cytokine release and mast cells degranulation (8), leads to hyperproliferation of epidermal keratinocytes, and stimulation of free nerve endings supports development of itch and erythema (9). ...
Introduction
The removal of unwanted hair is a widespread grooming practice adopted by both males and females. Although many depilatory techniques are now available, shaving remains the most common, despite its propensity to irritate skin. Current techniques to investigate the impact of shaving regimes on skin health rely on costly and lengthy clinical trials, which hinge on recruitment of human volunteers and can require invasive biopsies to elucidate cellular and molecular-level changes.
Methods
Well-characterised human skin equivalent technology was combined with a commonplace dermatological technique of tape stripping, to remove cellular material from the uppermost layer of the skin ( stratum corneum ). This method of exfoliation recapitulated aspects of razor-based shaving in vitro , offering a robust and standardised in vitro method to study inflammatory processes such as those invoked by grooming practices.
Results
Tape strip insult induced inflammatory changes in the skin equivalent such as: increased epidermal proliferation, epidermal thickening, increased cytokine production and impaired barrier function. These changes paralleled effects seen with a single dry razor pass, correlated with the number of tape strips removed, and were attenuated by pre-application of shaving foam, or post-application of moisturisation.
Discussion
Tape strip removal is a common dermatological technique, in this study we demonstrate a novel application of tape stripping, to mimic barrier damage and inflammation associated with a dry shave. We validate this method, comparing it to razor-based shaving in vitro and demonstrate the propensity of suitable shave- and skin-care formulations to mitigate damage. This provides a novel methodology to examine grooming associated damage and a platform for screening potential skin care formulations.
... Actually, age is reported to be associated with neither the severity nor the frequency rates of chemotherapy alopecia [21], but the regrowth of eyebrows, eyelash, and body hairs is accelerated in the premenopausal patients [21]. In apparent contrast to this view, white beard hairs, which are obviously more common in aged people, grow more than twice as fast (1.12 mm/day) as pigmented hairs (0.47 mm/day) [22] and, therefore, are supposedly more susceptible to antimitotic agents. In the direct experience of one of us, in fact, the beard thinned out after docetaxel (50 mg/m 2 every 15 days) along with scalp hairs, and both its black and white hairs exhibited the highest degree of dystrophy ("cadaverized" hairs) (Fig. 2a, b). ...
... Sheep fleece is not a perfect analogy for the hair of human beards. The follicles of sheep fleece average one fourth the diameter of human beard hair ($18 lm versus 75 lm; Bosman 1934;Floyd et al. 2018) and are much more densely packed (6000 follicles per cm 2 versus 70 follicles per cm 2 ; Bosman 1934; Maurer et al. 2016). This represents a five-fold greater crosssectional area of hair follicles for fleece than beards. ...
Because facial hair is one of the most sexually dimorphic features of humans (Homo sapiens) and is often perceived as an indicator of masculinity and social dominance, human facial hair has been suggested to play a role in male contest competition. Some authors have proposed that the beard may function similar to the long hair of a lion’s mane, serving to protect vital areas like the throat and jaw from lethal attacks. This is consistent with the observation that the mandible, which is superficially covered by the beard, is one of the most commonly fractured facial bones in interpersonal violence. We hypothesized that beards protect the skin and bones of the face when human males fight by absorbing and dispersing the energy of a blunt impact. We tested this hypothesis by measuring impact force and energy absorbed by a fiber epoxy composite, which served as a bone analog, when it was covered with skin that had thick hair (referred to here as “furred”) versus skin with no hair (referred to here as “sheared” and “plucked”). We covered the epoxy composite with segments of skin dissected from domestic sheep (Ovis aries), and used a drop weight impact tester affixed with a load cell to collect force versus time data. Tissue samples were prepared in three conditions: furred (n = 20), plucked (n = 20), and sheared (n = 20). We found that fully furred samples were capable of absorbing more energy than plucked and sheared samples. For example, peak force was 16% greater and total energy absorbed was 37% greater in the furred compared to the plucked samples. These differences were due in part to a longer time frame of force delivery in the furred samples. These data support the hypothesis that human beards protect vulnerable regions of the facial skeleton from damaging strikes.
... 4,5 The density of hair follicles and hair morphology depend on facial area and ethnicity. 6 Unlike scalp hair, beard hair fibers have more cuticle layers, larger cross sectional area, more variable in shape, and multidirectional growth pattern which is more complicated to shave. [7][8][9] Shaving of unwanted facial hair can be categorized into 2 methods, wet shaver (manual razors) and dry electric shaver. ...
Background: Facial shaving of beard and mustache in men is the most common cosmetic practice worldwide. There are many mentioned facial shaving-related skin problems due to misunderstanding. Irritation, razor burn, razor nick and pseudofolliculitis barbae (PFB) are frequently mentioned to be shaving related skin problems. Objective: This study aims to observe facial hair shaving behavior and shaving education knowledge in Thai male. Material and Methods: A questionnaire-based cross-sectional analytic studies of healthy men aged older than 18 who have facial hair shaved at least once per month was performed. Collected data included personal information, shaving details and shaving education knowledge.Results: Four hundred validated questionnaires were distributed randomly and checked for reliability before included for statistical analysis. Of all 358 replied questionnaires, 18 questionnaires with missing or unreliable data were sorted out. Finally, 340 cases were analyzed. The mean age was 34.8 ± 13.4 years old, most were wet shavers (77.4%). The mean frequency of shaving was 4 days per week. Only11.5% had shaving education or knowledge from their reliable sources. Conclusion: Facial hair shaving is the most common cosmetic practice in men but only few men had knowledge about correct shaving process.
... It should also be noted that the distribution and density of beard hair in adult males of China and other East Asian countries are much less compared with adult men of other races [22]. It also is common for East Asian men to shave their beards for personal hygiene [23]. Therefore, the possible use of beard hair for transplantation is sometimes underestimated. ...
Introduction
Beard hair serves as an important additional donor supply to support hair transplantation in hirsute patients with extensive alopecia and lacking sufficient occipital hair. However, the efficacy and safety of large-scale beard hair extraction have not been studied extensively in the East Asian population.
Methods
Data obtained from hirsute patients with extensive alopecia who underwent hair transplantation between March 2017 and December 2018 at Nanfang Hospital were analyzed. Occipital and beard hair were evaluated separately during the pre-, intra-, and post-operative periods. Individual beard hair follicular units (FUs) were harvested under tumescence using a hollow punch with an outer diameter of 0.8–0.9 mm. Follow-up examinations were scheduled at 3–5 days, 1 month, and 9 months postoperatively to check for complications, determine the survival rate of mixed, transplanted FU grafts, and assess patient satisfaction. Data were collected and analyzed statistically.
Results
A total of 36 hirsute, male patients with advanced androgenetic alopecia (AGA) (Norwood-Hamilton V–VI) were included in this study. The density of the occipital and beard areas was 78.6 ± 4.6 and 48.4 ± 9.3 FU, respectively. It took 3.1 ± 0.9 h to harvest 3135 ± 863 FUs from the occipital area and 2.1 ± 0.6 h to harvest 2352 ± 599 FUs from the beard area. The transection rate for occipital FUs and beard FUs was 3.7 ± 0.4 and 3.9 ± 0.2%, respectively. Completion of the operation took approximately 10.0 ± 0.9 h, and no serious complications were reported 5 days after the procedure. An FU survival rate of 95.7 ± 1.6% was observed at 9 months after transplantation, with no visible hypopigmented scars observed in the bare areas. All patients were satisfied with the resulting cosmetic appearance.
Conclusion
Large-scale beard extraction, when combined with occipital hair extraction, is a safe and effective treatment to enhance the cosmetic appearance of East Asian men with advanced AGA.
... sebum) that coat their surface [35], lower the friction properties of skin. Compared to scalp hairs, beard hairs exhibit low emerging angles with respect to the skin surface [147]. In relation to ageing, the emergence of skin wrinkles and alterations of the structuro-mechanical properties of the skin, it is logical to expect that the frictional properties of skin arising from the presence of hair would be affected by age, body location and type of hair. ...
RÉSUMÉ
Introduction
La pseudo-folliculite de la barbe (PFB) est une dermatose inflammatoire chronique, favorisée par le rasage et affectant essentiellement la barbe, mais aussi les autres zones du corps rasées (pubis, aisselles). Elle est particulièrement fréquente chez les Noirs africains, causant un important préjudice esthétique et professionnel. Cependant, il existe très peu de données disponibles pour cette affection, surtout en Afrique subsaharienne. Notre objectif était de déterminer les aspects épidémiologiques et cliniques, ainsi que les facteurs de risque associés à la survenue de la PFB à Dakar.
Population et méthode
Il s’agit d’une étude transversale descriptive à visée analytique, réalisée en mars 2019, portant sur 655 élèves policiers pensionnaires de l’école nationale de police de Dakar, tous d’ascendance africaine et porteurs de cheveux crépus soumis à une obligation de rasage hebdomadaire. Le diagnostic de PFB était clinique.
Résultats
Sur les 655 élèves policiers, 254 présentaient une PFB, soit une prévalence de 38,8 %. La prévalence de la PFB était de 43,7 % chez les hommes et de 11,9 % chez les femmes. L’âge moyen des élèves présentant la PFB était de 26,8 ans. L’âge de début de la PFB était compris entre 18 et 22 ans chez la majorité (53,9 %). Les lésions de PFB étaient prurigineuses dans 84,6 % des cas, à type de papules dans 96,8 % des cas et/ou de pustules dans 60,2 % des cas. La région sous-mandibulaire était le site le plus affecté (69,8 %). Des complications étaient notées dans 90,1 % des cas, surtout à type d’hyperpigmentation post-inflammatoire (87 %). Les facteurs de risque associés à la PFB étaient le sexe masculin, l’existence d’un antécédent familial de PFB, la peau à tendance chéloïdienne, l’association à une folliculite fibrosante de la nuque, l’utilisation de rasoirs à lame unique ou à tête fixe, le rasage à contre-sens du poil, le non-usage de produits de rasage et l’épilation à la cire.
Conclusion
Notre étude confirme la fréquence élevée de la PFB dans cette population d’hommes noirs d’ascendance africaine. Une anomalie génétique révélée par le rasage doit être évoquée dans la survenue de la PFB, nécessitant ainsi d’autres études sur le plan génétique et immunohistochimique.
Objective
Electrical epilation of unwanted hair is a widely used hair removal method, but it is largely unknown how this affects the biology of human hair follicles (HF) and perifollicular skin. Here, we have begun to explore how mechanical epilation changes selected key biological read‐out parameters ex vivo within and around the pilosebaceous unit.
Methods
Human full‐thickness scalp skin samples were epilated ex vivo using an electro‐mechanical device, organ‐cultured for up to 6 days in serum‐free, supplemented medium, and assessed at different time points by quantitative (immuno‐)histomorphometry for selected relevant read‐out parameters in epilated and sham‐epilated control samples.
Results
Epilation removed most of the hair shafts, often together with fragments of the outer root sheath and hair matrix. This was associated with persistent focal thinning of the HF basal membrane, decreased melanin content of the residual HF epithelium, and increased HF keratinocyte apoptosis, including in the bulge, yet without affecting the number of cytokeratin 15 ⁺ HF epithelial stem cells. Sebocyte apoptosis in the peripheral zone was increased, albeit without visibly altering sebum production. Epilation transiently perturbed HF immune privilege and increased the expression of ICAM‐1 in the bulge and bulb mesenchyme, and the number of perifollicular MHC class II ⁺ cells as well as mast cells around the distal epithelium and promoted mast cell degranulation around the suprabulbar and bulbar area. Moreover, compared to controls, several key players in neurogenic skin inflammation, itch, and/or thermosensation (TRPV1, TRPA1, NGF, and NKR1) were differentially expressed in post‐epilation skin.
Conclusion
These data generated in denervated, organ‐cultured human scalp skin demonstrate that epilation‐induced mechanical HF trauma elicits surprisingly complex biological responses. These may contribute to the delayed re‐growth of thinner and lighter hair shafts post‐epilation and temporary post‐epilation discomfort. Our findings also provide pointers regarding the development of topically applicable agents that minimize undesirable sequelae of epilation.
Facial hair is a commonly desired feature for many individuals. Despite a breadth of dermatology literature covering strategies for removing facial hair, there are no known articles summarizing strategies for facial hair growth or reviewing common facial hair pathologies. Here, we assess Google Trends to describe significant increases in terms related to facial hair growth and maintenance over the last decade, suggesting an increased public interest on this topic. Next, we review ethnic differences in facial hair growth that may affect facial hair distribution, growth, and predisposition to certain facial hair pathologies. Lastly, we review studies on agents used for facial hair growth and review common facial hair pathologies.
Alopecia areata (AA) is a CD8+ T-cell dependent autoimmune disease of the hair follicle (HF) in which the collapse of HF immune privilege (IP) plays a key role. Mast cells (MCs) are crucial immunomodulatory cells implicated in the regulation of T cell-dependent immunity, IP, and hair growth. Therefore, we explored the role of MCs in AA pathogenesis, focusing on MC interactions with CD8+ T-cells in vivo, in both human and mouse skin with AA lesions. Quantitative (immuno-)histomorphometry revealed that the number, degranulation and proliferation of perifollicular MCs are significantly increased in human AA lesions compared to healthy or non-lesional control skin, most prominently in subacute AA. In AA patients, perifollicular MCs showed decreased TGFβ1 and IL-10 but increased tryptase immunoreactivity, suggesting that MCs switch from an immuno-inhibitory to a pro-inflammatory phenotype. This concept was supported by a decreased number of IL-10+ and PD-L1+ MCs, while OX40L+, CD30L+, 4-1BBL+ or ICAM-1+ MCs were increased in AA. Lesional AA-HFs also displayed significantly more peri- and intrafollicular- CD8+ T-cells as well as more physical MC/CD8+ T-cell contacts than healthy or non-lesional human control skin. During the interaction with CD8+ T-cells, AA MCs prominently expressed MHC class I and OX40L, and sometimes 4-1BBL or ICAM-1, suggesting that MC may present autoantigens to CD8+ T-cells and/or co-stimulatory signals. Abnormal MC numbers, activities, and interactions with CD8+ T-cells were also seen in the grafted C3H/HeJ mouse model of AA and in a new humanized mouse model for AA. These phenomenological in vivo data suggest the novel AA pathobiology concept that perifollicular MCs are skewed towards pro-inflammatory activities that facilitate cross-talk with CD8+ T-cells in this disease, thus contributing to triggering HF-IP collapse in AA. If confirmed, MCs and their CD8+ T-cell interactions could become a promising new therapeutic target in the future management of AA.
The skin as a barrier and immune organ is exposed to omnipresent environmental challenges such as irradiation or chemical and biologic hazards. Neuropeptides released from cutaneous nerves or skin and immune cells in response to noxious stimuli are mandatory for a fine-tuned regulation of cutaneous immune responses and tissue maintenance and repair. They initialize host immune responses, but are equally important for counter regulation of proinflammatory events. Interaction of the nervous and immune systems occurs both locally – at the level of neurogenic inflammation and immunocyte activation – and centrally – by controlling inflammatory pathways such as mononuclear activation or lymphocyte cytokine secretion. Consequently, a deregulated neurogenic immune control results in disease manifestation and frequently accompanies chronic development of cutaneous disorders. The current understanding, therapeutic options, and open questions of the role that neuropeptides such as substance P, calcitonin gene-related peptide, vasoactive intestinal peptide/pituitary adenylate cyclase-activating polypeptide, neuropeptide Y, or others play in these events are discussed. Progress in this field will likely result in novel therapies for the management of diseases characterized by deregulated inflammation, tissue remodeling, angiogenesis, and neoplasm.Abbreviations: AM, adrenomedullin; APC, antigen presenting cells; BK, bradykinin; B1 and B2, BK receptors; CGRP, calcitonin gene-related peptide; DC, dendritic cell; IP, inositol 1,4,5-phosphate; NEP, neutral endopeptidase; NGF, nerve growth factor; PACAP, pituitary adenylate cyclase activating polypeptide; SP, substance P; TRPV, transient receptor potential channel vanilloid subfamily; VPAC1 and VPAC2, receptors for VIP/PACAP; VIP, vasoactive intestinal peptide
Post-menopausal women have an increased risk of developing a number of degenerative pathological conditions, linked by the common theme of excessive inflammation. Systemic estrogen replacement (in the form of hormone replacement therapy) is able to accelerate healing of acute cutaneous wounds in elderly females, linked to its potent antiinflammatory activity. However, in contrast to many other age-associated pathologies, the detailed mechanisms through which estrogen modulates skin repair, particularly the cell type-specific role of the two estrogen receptors, ERalpha and ERbeta, has yet to be determined. Here, we use pharmacological activation and genetic deletion to investigate the role of both ERalpha and ERbeta in cutaneous tissue repair. Unexpectedly, we report that exogenous estrogen replacement to ovariectomised mice in the absence of ERbeta actually delayed wound healing. Moreover, healing in epidermal-specific ERbeta null mice (K14-cre/ERbeta(L2/L2)) largely resembled that in global ERbeta null mice. Thus, the beneficial effects of estrogen on skin wound healing are mediated by epidermal ERbeta, in marked contrast to most other tissues in the body where ERalpha is predominant. Surprisingly, agonists to both ERalpha and ERbeta are potently antiinflammatory during skin repair, indicating clear uncoupling of inflammation and overall efficiency of repair. Thus, estrogen-mediated antiinflammatory activity is not the principal factor in accelerated wound healing.
The ongoing search for explanations as to why elderly males heal acute skin wounds more slowly than do their female counterparts (and are more strongly disposed to conditions of chronic ulceration) has identified endogenous oestrogens and androgens as being respectively enhancers and inhibitors of repair. We previously demonstrated that blocking the conversion of testosterone to 5alpha-dihydrotestosterone (DHT) limits its ability to impair healing, suggesting that DHT is a more potent inhibitor of repair than is testosterone. The present study aimed to delineate the central mechanisms by which androgens delay repair. Whilst the contractile properties of neither rat wounds in vivo nor fibroblast-impregnated collagenous discs in vitro appeared to be influenced by androgen manipulations, the global blockade of DHT biosynthesis markedly accelerated re-epithelialization of incisional and excisional wounds and reduced local expression of beta-catenin, a key inhibitor of repair. Moreover, DHT retarded the in vitro migration of epidermal keratinocytes following scratch wounding. By contrast, it failed to influence the migratory and proliferative properties of dermal fibroblasts, suggesting that its primary inhibitory effect is upon re-epithelialization. These novel findings may be of particular significance in the context of chronic ulceration, for which being male is a key risk factor.
There is a growing awareness that some individuals exhibit heightened skin sensitivity, particularly on the face, and have a high incidence of adverse reactions to cosmetics and toiletries.
To carry out an epidemiological study to assess the prevalence of sensitive skin and cosmetic-related adverse events in a U.K. population, and to examine possible factors that may be associated with sensitive skin.
Self-assessment questionnaires were sent out to 3300 women and 500 men, randomly selected, who were over the age of 18 years and lived within a 10-mile radius of High Wycombe (Bucks.). Fifty non-responder women were also questioned by telephone to ensure that the postal responders were representative of the population as a whole.
The response rates were 62% for women and 52% for men, with the incidence of self-reported skin sensitivity being 51.4% and 38.2%, respectively. Ten per cent of women and 5.8% of men described themselves as having very sensitive skin. Fifty-seven per cent of women and 31.4% of men had experienced an adverse reaction to a personal product at some stage in their lives, with 23% of women and 13.8% of men having had a problem in the last 12 months. Among the women, symptoms of cosmetic-induced subjective sensory skin discomfort (burning, stinging, itching etc.) occurred more commonly in the sensitive skin cohort (53%) than in those who regarded themselves as non-sensitive (17%). An atopic diathesis in women did not appear to be a predictive factor for sensitive skin, the incidence of self-perceived sensitive skin being equivalent for atopics (49%) and non-atopics (51%). Furthermore, some 34% of atopic women described themselves as being non-sensitive. Nevertheless, the incidence of atopy was higher among the women in the sensitive skin group (49%) than among those in the non-sensitive group (27%). Dry skin and a predilection for blushing/flushing were associated factors for sensitive skin.
Our survey indicates that sensitive facial skin is a common problem for women and men in the U.K. and points to the need for the development of personal products designed for this skin phenotype.
While the enormous clinical and psychosocial importance of pruritus in many areas of medicine and the detrimental effects of chronic 'itch' on the quality of life of an affected individual are widely appreciated, the complexity of this sensation is still often grossly underestimated. The current Controversies feature highlights this complexity by portraying pruritus as a truly interdisciplinary problem at the crossroads of neurophysiology, neuroimmunology, neuropharmacology, protease research, internal medicine, and dermatology, which is combated most successfully if one keeps the multilayered nature of 'itch' in mind and adopts a holistic treatment approach - beyond the customary, frequently frustrane monotherapy with histamine receptor antagonists. In view of the often unsatisfactory, unidimensional, and altogether rather crude standard instruments for pruritus management that we still tend to use in clinical practice today, an interdisciplinary team of pruritus experts here critically examines recent progress in pruritus research that future itch management must take into consideration. Focusing on new insights into the neuroimmunological, neuroendocrine, and neurophysiological bases of pruritus, and discussing available neuropharmacological tools, specific research avenues are highlighted, whose pursuit promises to lead to novel, and hopefully more effective, forms of pruritus management.
This review focuses on the role of the peripheral nervous system in cutaneous biology and disease. During the last few years, a modern concept of an interactive network between cutaneous nerves, the neuroendocrine axis, and the immune system has been established. We learned that neurocutaneous interactions influence a variety of physiological and pathophysiological functions, including cell growth, immunity, inflammation, pruritus, and wound healing. This interaction is mediated by primary afferent as well as autonomic nerves, which release neuromediators and activate specific receptors on many target cells in the skin. A dense network of sensory nerves releases neuropeptides, thereby modulating inflammation, cell growth, and the immune responses in the skin. Neurotrophic factors, in addition to regulating nerve growth, participate in many properties of skin function. The skin expresses a variety of neurohormone receptors coupled to heterotrimeric G proteins that are tightly involved in skin homeostasis and inflammation. This neurohormone-receptor interaction is modulated by endopeptidases, which are able to terminate neuropeptide-induced inflammatory or immune responses. Neuronal proteinase-activated receptors or transient receptor potential ion channels are recently described receptors that may have been important in regulating neurogenic inflammation, pain, and pruritus. Together, a close multidirectional interaction between neuromediators, high-affinity receptors, and regulatory proteases is critically involved to maintain tissue integrity and regulate inflammatory responses in the skin. A deeper understanding of cutaneous neuroimmunoendocrinology may help to develop new strategies for the treatment of several skin diseases.
Human hair has been commonly classified according to three conventional ethnic human subgroups, that is, African, Asian, and European. Such broad classification hardly accounts for the high complexity of human biological diversity, resulting from both multiple and past or recent mixed origins. The research reported here is intended to develop a more factual and scientific approach based on physical features of human hair. The aim of the study is dual: (1) to define hair types according to specific shape criteria through objective and simple measurements taken on hairs from 1442 subjects from 18 different countries and (2) to define such hair types without referring to human ethnicity. The driving principle is simple: Because hair can be found in many different human subgroups, defining a straight or a curly hair should provide a more objective approach than a debatable ethnicity-based classification. The proposed method is simple to use and requires the measurement of only three easily accessible descriptors of hair shape: curve diameter (CD), curl index (i), and number of waves (w). This method leads to a worldwide coherent classification of hair in eight well-defined categories. The new hair categories, as described, should be more appropriate and more reliable than conventional standards in cosmetic and forensic sciences. Furthermore, the classification can be useful for testing whether hair shape diversity follows the continuous geographic and historical pattern suggested for human genetic variation or presents major discontinuities between some large human subdivisions, as claimed by earlier classical anthropology.
Hair removal practices have their roots in antiquity. While modern global attitudes towards hair removal vary, consumers around the world use blade shaving as a method to effect hair removal. Modern blades and razors are the product of extensive research and technologically advanced manufacturing procedures; these combine to provide the user with an optimum shaving experience. Effective blade shaving involves three steps: preparation, including skin cleansing and hair hydrating; hair removal, including the use of an appropriate shaving preparation; and post-shave skin care, including moisturizer application.
Hair follicles (HFs) undergo life-long cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative "quiescence" (telogen). Since HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. While available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. Here, we present such a guide, which uses objective, well-defined, and reproducible criteria and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in sub-optimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field.Journal of Investigative Dermatology accepted article preview online, 09 September 2015. doi:10.1038/jid.2015.354.
Background
Types of body washesMajor formula components of body washesIn-use performance considerations for body washesWho will benefit from using body washes?Conclusions
References
Over the last few decades, progress in molecular biology and genetics, as well as the development of new experimental approaches, has brought together scientists from all fields. Developmental biologists, geneticists, endocrinologists, and dermatologists now study the many diverse facets of hair follicle biology including neuroectodermal– mesenchymal interactions, immunology, pigmentation, and stem cell biology.
Background
The contribution of the nervous system to inflammation in general and inflammatory skin disease in particular has been underappreciated. It is now apparent that an intact neural component is required for the conventional clinical manifestations of many inflammatory skin diseases.Objectives
To investigate the relationship between nerve damage and skin disease.Methods
Previous individual reports since 1966 were collected systematically and the clinical observations described therein were placed within current concepts of neurogenic inflammation.ResultsWe reviewed the literature and identified 23 cases of alterations in the appearance or distribution of skin disorders in patients with acquired central or peripheral neural damage or dysfunction. In 19 cases, near or complete resolution of pre-existing skin lesions occurred in areas directly or indirectly supplied by a subsequently injured nervous system. Exacerbation or new onset of skin lesions occurred in only four cases. The neural deficits described included damage within the peripheral or central nervous system resulting in pure sensory, pure motor or combined sensory and motor deficits.Conclusions
These cases highlight the importance of neural innervation and neurogenic inflammation in the development of inflammatory skin disease and prompt further examination of the use of neural blockade as an adjunctive therapy in the treatment of inflammatory dermatoses.
The term ‘neurogenic inflammation’ has been adopted to describe the local release of inflammatory mediators, such as substance P and calcitonin gene-related peptide, from neurons. Once released, these neuropeptides induce the release of histamine from adjacent mast cells. In turn, histamine evokes the release of substance P and calcitonin gene-related peptide; thus, a bidirectional link between histamine and neuropeptides in neurogenic inflammation is established. The aim of this review is to summarize the most recent findings on the role of histamine in neurogenic inflammation, with particular regard to nociceptive pain, as well as neurogenic inflammation in the skin, airways and bladder.
This article is part of a themed issue on Histamine Pharmacology Update. To view the other articles in this issue visit http://dx.doi.org/ 10.1111/bph.2013.170.issue-1
Previous studies have shown that the clinical genesis and onset of facial wrinkles as well as the morphology of the extracellular matrix differ between the sexes. The aim of this present clinical study was to do the first systematic assessment of gender-related differences in skin elasticity, with special focus on age-related changes.
300 healthy male and female subjects (20-74 years) were selected following strict criteria including age, sun behavior or smoking habits. Skin mechanical properties were assessed at the cheek, neck, volar forearm and dorsum of the hand using a non-invasive suction device.
Data analysis shows a significant negative correlation for all parameters and subject's age. At young age results of the relative parameters are higher for women, whereas absolute parameters are higher for men. Parameters referring to the recovery phase change stronger with aging.
The present study verifies the progressive decline of the skin mechanical properties with aging. However, the elastic ability of the skin to recover after stretching is more strongly affected by the aging process than the firmness of the skin. Further, the mechanical properties change differently in men and woman over lifetime.
The cutting behaviour of beard hair has been investigated quantitatively and qualitatively. High speed cutting tests were
conducted on beard hair samples using a purpose built cutting rig (provided by Gillette, UK) to determine the cutting forces.
High speed digital video photography was used to record the cutting process. In parallel with these tests, low speed cutting
tests were undertaken within a scanning electron microscope (SEM) to gain a better understanding of the cutting process. Results
from the high speed cutting tests showed that the peak cutting stresses are influenced strongly by moisture (the cutting stress
for ‘wet’ samples is reduced by about 30% as compared to dry samples) while the effects on the cutting stress of other variables
(subject age, blade approach angle and sample ageing due to prolonged storage) appeared to be less noticeable. The angle of
cut was affected by the distance of the initial contact point (between the hair and the blade) from the base of the hair with
the line of cut shifting towards the hair axis with increasing distance from the base. Qualitative observations from video-recordings
and still images taken during the cutting tests, conducted in-situ within the SEM as well as the high speed cutting rig, showed
four main cutting mechanisms of hair, which are documented in this paper. The distance from the initial contact point to the
base of the hair and the moisture level were the parameters which controlled the mechanism of failure. Qualitative observations
of the sort reported here are a necessary pre-cursor to the development of finite element models to simulate a cutting operation.
Objectives:
Evidence is given that differences in skin physiological properties exist between men and women. However, despite an assessable number of available publications, the results are still inconsistent. Therefore, the aim of this clinical study is the first systematic assessment of gender-related differences in skin physiology in men and women, with a special focus on changes over lifetime.
Methods:
A total of 300 healthy male and female subjects (20-74 years) were selected following strict criteria including age, sun behaviour or smoking habits. TEWL, hydration level, sebum production and pH value were measured with worldwide-acknowledged biophysical measuring methods at forehead, cheek, neck, volar forearm and dorsum of hand.
Results:
Until the age of 50 men's TEWL is significantly lower than the water loss of women of the same age, regardless of the location. With ageing gender-related differences in TEWL assimilate. Young men show higher SC hydration in comparison with women. But, whereas SC hydration is stable or even increasing in women over lifetime, the skin hydration in men is progressively decreasing, beginning at the age of 40. Sebum production in male skin is always higher and stays stable with increasing age, whereas sebum production in women progressively decreases over lifetime. Across all localizations and age groups, the pH value in men is below 5, the pH value of female subjects is, aside from limited expectations, higher than 5.
Conclusion:
Skin physiological distinctions between the sexes exist and are particularly remarkable with regard to sebum production and pH value.
Objectives:
Today, a majority of the general population describe themselves as having sensitive skin. Although this is often considered more of a problem for women, the number of men claiming this condition is substantial. The objective of these studies was to evaluate dermatologists' perceptions with regard to the prevalence of sensitive skin among men, and the potential impact of influencing factors.
Methods:
Questionnaire surveys were conducted among two groups; a European survey (1531 subjects), which included dermatologists from several geographical regions, and a US Internet survey (300 subjects).
Results and conclusion:
The majority of dermatologists in both studies (82.0% and 58.3%, respectively) either agreed or strongly agreed that they have noticed an increase in male patients reporting sensitive facial skin over the past 5 years. Some regional differences were apparent in the European survey, with a significantly (P ≤ 0.05) higher proportion agreeing in Central/Eastern Europe (84.9%) and Asia (89.9%) compared with Western Europe (75.1%). General factors cited that could influence the incidence of perceived skin sensitivity included environmental factors, stress, increased acceptance in society and increased use of products. With the exception of UV light exposure, which was cited by a majority of dermatologists in all geographical regions, exacerbating environmental factors differed in a manner that may have been related to differing climates in the regions. In both surveys, over 90% of responders agreed that the selection of shaving products was important for men with sensitive skin.
Historically, most cosmetic and medical cosmetic research has been focused on the female consumer. Advancements in the development of grooming instruments as well as changing consumer habits and attitudes toward male cosmetic skin care needs support the need to develop a deeper understanding of male skin biology and how that can be used to improve the quality of life relative to societal interactions. Male skin biology has been found to have unique properties that are distinct from females and have a significant impact on the way males groom and maintain their overall appearance. Research to date has found that male skin has a different response profile to such environmental insults as UV, heat, and stress that is based not on just differences in cosmetic or dermatological product usage but also on underlying biological differences. These differences are discussed with the implications to a broader understanding of male facial skin care needs that spans from daily grooming practices to overall health status that impacts higher incidence rate of skin cancer among males. This highlights that male skin care has a holistic need to ensure proper grooming and sunscreen moisturizer usage.
Past research on understanding gender differences of skin biology and its response to environmental insults has focused on morphological and gross physiological comparisons. In general it has been found that male skin has a greater susceptibility to being negatively impacted by environmental stressors, in particular ultraviolet radiation. These noted differences in response to environmental insults are probably due to a combination of underlying biologically based differences and variable sun-protection and skin-care product usage between genders. Overall, published data support the hypothesis that male facial skin undergoes significant challenges from environmental insults that lead to a more damaged condition compared with female skin. These changes occur both from acute insults and from the impact of cumulative chronic exposure. Appropriate sun protection should be viewed as an important step in male skin care and grooming habits.
A key characteristic of mast cells appears to be an ability to span the division between nervous and immune system. Indeed, much of our understanding of the bi-directional relationship between the nervous and immune systems has come from the study of mast cell-nerve interaction. Although differences in species have been reported, morphologic as well as functional associations between mast cell and nerves are found in most tissues in many mammalian species, including humans. These interactions are involved in the regulation of physiologic homeostatic processes as well as in disease mechanisms. Here we discuss the influence of cholinergic and sensory neurons on mast cells as well as the importance of mast cell nerve interactions at specific tissue sites, including the brain.
Abstract While the central rôle of mast cells (MC) in allergy and inflammation is well-appreciated, much less is known about their physiological functions. The impressive battery of potent growth modulatory MC products, and increasing evidence of MC involvement in hyperproliferalive and librotic disorders suggest that tissue remodelling may be one of those, namely in the skin. Here, we delineate why this may best be studied by analysing the potential role of MC in hair growth regulation. On the background of numerous, yet widely under-appreciated hints from the older literature, we summarize and discuss our recent observations from the C57BL/6 mouse model for hair research which support the concept that MC are functionally important modulators of hair follicle cycling, specifically during anagen development. This invites to exploit the murinc hair cycle as a model for dissecting the physiological growth modulatory functions of MC and encourages the exploration of MC-targeting pharmaceutical strategies for the treatment of hair growth disorders.
Grooming habits of men in China have some marked differences from those in other areas in the world, with a high percentage of men resorting to shaving with an electric razor. This is influenced by multiple factors, such as a lower facial hair growth density concentrated in a small area around the mouth. Further, there is limited knowledge and misconceptions around the alleged negative skin effects of blade shaving.
To compare skin in the shaved area with that of the rest of the face, and to compare the impact of shaving with a modern three-blade razor vs. electric shaving.
Pilot clinical studies including 50 and 40 healthy Chinese men, respectively.
Skin in the shaved area is different from the rest of the face, with a higher temperature, lower hydration and diminished skin barrier function. Regular shaving with a modern multiblade razor was not statistically different from dry shaving in terms of impact on barrier function.
Shaving with a modern multiblade razor could even deliver certain skin benefits in the area of facial oil control and reducing skin flakes.
Male skin care needs are heavily influenced by the need to remove facial hair on a regular basis. Facial skin issues associated with poor hair removal approaches are common and include razor burn and irritation. This paper evaluates current research on shaving technology and how careful ingredient selection can contribute to male skin health. The importance of maintaining hair softness during the shave and restoring facial hydration post-shave is discussed. Data are presented on how post-shave moisturizers containing glycerine and emollients can create an environment for improved barrier function which can be further improved by incorporating specific ingredients such as niacinamide.
Male grooming has its roots in antiquity. Control and styling of facial hair has invariably required the development and use of metal instrumentation. Once crude and unreliable, it has latterly become sophisticated and subject to intense research and development at the highest scientific level. This paper describes how male grooming is being impacted by improvements in fundamental understanding of male skin. Skin issues associated with poor hair removal approaches are common, but are often overlooked or their aetiology misunderstood by patients and physicians. By incorporating advanced scientific measurement and imaging technology into clinical testing, insights are being gained into both the common concerns which men express and optimal solutions for these concerns. Specific aspects such as the study of nicks and cuts and the identification and release of trapped hairs are discussed. Finally, details are presented on how the individual elements of technologically advanced razors play a role in managing the skin and hair, highlighting further the complexity of the shaving process.
The use of cosmetics and medical cosmetic procedures by men has been widely ignored in dermatological research in the past, but it is finding increasing attention. As men are changing their habits and increasingly tend to use cosmetic products, the dermatologist will be asked for expert advice regarding efficacy and safety of cosmetics for male skin. For this service, dermatologists need to be aware of anatomical and physiological differences between male and female skin, about specific environmental stress factors affecting male skin, about cosmetic practices and product use especially regarding shaving, and about the counselling needs in men relating to protective cosmetic use.
Mast cells often represent one of the first cells of the immune system to interact with environmental antigens, invading pathogens or environmentally-derived toxins. Mast cells also can undergo alterations in phenotype, anatomic distribution and numbers during innate or adaptive immune responses. In addition to their well-known roles as effector cells during IgE- and antigen-induced allergic reactions, mast cells can be activated by many other signals, including some that are derived directly from pathogens or which are generated during innate or adaptive immune responses. Mast cells also express many costimulatory molecules with immunoregulatory activities and can secrete many products that can positively or negatively regulate immune responses. In this chapter, we describe mouse models used for analyzing mast-cell function in vivo and illustrate how such models have been used to identify positive or negative immunomodulatory roles for mast cells during specific innate or adaptive immune responses. We also briefly describe some of the mast-cell functions, products and surface receptors that have the potential to permit mast cells to promote or suppress immune responses that can either enhance host defense or contribute to disease.
Mast cells are powerful inflammatory cells which are in close functional and anatomical association with sensory nerves in the skin. During psychological stress the neuroendocrine system and peripheral sensory nerves are activated leading to release of mediators, such as neuropeptides, neurotrophins, corticotropin-releasing hormone and a-melanocyte-stimulating hormone, which are capable of activating mast cells. On the other hand, mast cell mediators released, e.g. histamine, tryptase and nerve growth factor, can in turn excite and stimulate surrounding neuropeptide-containing C-fibers possibly resulting in feedforward loop and potentiation of neurogenic inflammation. In these mechanisms, proinflammatory cytokines and chemokines are released from mast cells. In chronic skin diseases, psoriasis, atopic dermatitis and palmoplantar pustulosis, the contacts between tryptase-positive mast cells and sensory nerves are increased in number, which provides the morphological basis for increased mast cell - sensory nerve interaction in chronically inflamed skin. Hence, in this review the current understanding of the role of cutaneous mast cells and sensory nerves and their activation in psychic stress is discussed.
There is currently a debate in the literature on chemical drug analysis concerning the contribution of biophysical attributes associated with specimens and specimen donors to assay outcome. In recent years this debate has focused on hair analysis, but has in the past also been raised in urinalysis interpretation. In this article we examine several aspects of that controversy. First, we present data regarding the effects of hair color on the distribution of positive hair testing results for three drug classes. We compare these results to negative hair samples from comparable donors. This data is derived from head hair from preemployment donors that was classified according to seven visual color categories. We determined the distribution of colors for hair samples devoid of any of three assayed drugs (amphetamines, cocaine, and cannabinoids). Subsequently, this distribution was compared with the distributions for hairs that had tested positive for amphetamines, cocaine or cannabinoids. We examined a total of 2000 randomly selected samples; 500 negative hair samples and 500 positive samples for each of three drugs: cannabinoids, cocaine, and amphetamine. We also evaluated ethnic/racial factors in relation to positive urinalyses for various ethnic/racial groups. We examined approximately 4000 urine specimens from two different groups, each constituting around 2000 specimens. In addition to ethnicity/race and urinalysis outcome, we also examined the relationship between the hair color distributions of urine donors and the corresponding urinalysis results for the three drug classes. We also compared them to drug-negative samples. Our summary impression is that the observed outcome patterns were largely consistent with differences in drug preferences among the various societal groups. There was little evidence of a pattern attributable to hair color bias alone or selective binding of drugs to hair of a particular color. Likewise, there was no discernible pattern associated with race or ethnicity that would lend support to a “race effect” in drug analysis.
Various parameters of hair growth were determined every 28 days for 18 months in 14 healthy Caucasian men aged 18-39 with indoor occupations in Sheffield, U.K. (latitude 53.4 degrees N). In the scalp the proportion of follicles in anagen reached a single peak of over 90% in March, and fell steadily to a trough in September. The number of shed hairs reached a peak around August/September, when least follicles were in anagen. At this time the average loss of hairs was about 60 per day, more than double that during the preceding winter. The rate of growth of the beard was lowest in January and February and increased steadily from March to July to reach a peak about 60% above the winter level. The rate of growth of thigh hair showed a similar pattern though with less pronounced differences. No seasonal fluctuations in finger- or toenail growth were detected.
A considerable difference in growth rates of pigmented and white anagen beard hair (0.47 mm/day vs. 1.12 mm/day, on average) was measured in three individuals over a 3-year period. Nuclear differentiation in the suprabulbar region of hair shafts revealed an earlier, and more intensive, condensation of chromatin in pigmented hair than in white hair. As other differences (diameter, presence or absence of medulla) between the two hair types could be excluded, the results suggest earlier terminal differentiation of pigmented hair compared with white hair.
While the central role of mast cells (MC) in allergy and inflammation is well-appreciated, much less is known about their physiological functions. The impressive battery of potent growth modulatory MC products, and increasing evidence of MC involvement in hyperproliferative and fibrotic disorders suggest that tissue remodelling may be one of those, namely in the skin. Here, we delineate why this may best be studied by analysing the potential role of MC in hair growth regulation. On the background of numerous, yet widely under-appreciated hints from the older literature, we summarize and discuss our recent observations from the C57BL/6 mouse model for hair research which support the concept that MC are functionally important modulators of hair follicle cycling, specifically during anagen development. This invites to exploit the murine hair cycle as a model for dissecting the physiological growth modulatory functions of MC and encourages the exploration of MC-targeting pharmaceutical strategies for the treatment of hair growth disorders.
Increasing evidence supports a role for mast cells (MC) in the control of tissue remodeling. Using the cyclic growth and regression activity of the murine hair follicle (HF) as a model, we have previously demonstrated that MC are involved in regulating the HF transformation from resting (telogen) to active hair growth (anagen). In the present study, we investigated the potential role of skin MC in spontaneous HF regression (catagen), a rapid and highly controlled process of organ involution characterized by massive epithelial cell apoptosis. By histochemistry, immunohistochemistry, and electron microscopy, we first assessed the number, location, and granulation status of perifollicular MC during the anagen-catagen-telogen transformation of back skin HF. Spontaneous catagen induction was associated with a dramatic reduction of dermal MC numbers, preceded by an increase in the percentage of degranulated MC. In vivo, the MC-secretagogues substance P and adrenocorticotropic hormone induced premature and dystrophic catagen development in anagen HF, whereas inhibitors of MC degranulation retarded normal catagen development. Comparing HF cycling in MC-deficient WBB6F1-KitW/KitWv and congenic normal (+/+) mice, catagen development was retarded in the virtual absence of MC. These data support the notion that MC function as hair cycle regulators and are involved in the control of HF regression. The mouse model employed here offers an excellent tool for dissecting the physiologic role of MC as "central switchboards of tissue remodeling" in developmentally regulated systems, specifically in organ involution processes.
The meager data on normal hair density in humans have been gathered from a predominantly white population. Examination of scalp biopsy specimens from African Americans suggests that hair density in this group may be lower than in whites. This study was performed to quantify any differences between white and African American patients.
A retrospective case series of subjects who had undergone a biopsy of clinically healthy scalp skin. The 4-mm punch biopsy specimens were sectioned, and all follicles contained within the specimens were counted at various levels (suprabulbar, isthmus, and infundibulum) to arrive at the number and type of hairs present.
Outpatient clinic in a tertiary care medical center.
A consecutive sample of 22 African American and 12 white patients with clinically healthy scalp skin specimens that were studied and compared with previously reported data.
Patients' age and total number of follicles, terminal follicles, vellus follicles, terminal anagen hairs, and terminal telogen hairs.
Total hair density (number of follicles per 4-mm punch biopsy specimen) and total number of terminal follicles and terminal anagen hairs were significantly lower in African Americans (P<.001) than in whites and in a previously reported, predominantly white, population.
Hair density in African Americans is significantly lower than that in whites, which must be taken into consideration when evaluating a biopsy specimen from an African American patient. Data previously collected from white patients may not provide adequate guidance when evaluating scalp biopsy specimens from African Americans and could lead to an incorrect diagnosis.
There is currently a debate in the literature on chemical drug analysis concerning the contribution of biophysical attributes associated with specimens and specimen donors to assay outcome. In recent years this debate has focused on hair analysis, but has in the past also been raised in urinalysis interpretation. In this article we examine several aspects of that controversy. First, we present data regarding the effects of hair color on the distribution of positive hair testing results for three drug classes. We compare these results to negative hair samples from comparable donors. This data is derived from head hair from preemployment donors that was classified according to seven visual color categories. We determined the distribution of colors for hair samples devoid of any of three assayed drugs (amphetamines, cocaine, and cannabinoids). Subsequently, this distribution was compared with the distributions for hairs that had tested positive for amphetamines, cocaine or cannabinoids. We examined a total of 2000 randomly selected samples; 500 negative hair samples and 500 positive samples for each of three drugs: cannabinoids, cocaine, and amphetamine. We also evaluated ethnic/racial factors in relation to positive urinalyses for various ethnic/racial groups. We examined approximately 4000 urine specimens from two different groups, each constituting around 2000 specimens. In addition to ethnicity/race and urinalysis outcome, we also examined the relationship between the hair color distributions of urine donors and the corresponding urinalysis results for the three drug classes. We also compared them to drug-negative samples. Our summary impression is that the observed outcome patterns were largely consistent with differences in drug preferences among the various societal groups. There was little evidence of a pattern attributable to hair color bias alone or selective binding of drugs to hair of a particular color. Likewise, there was no discernible pattern associated with race or ethnicity that would lend support to a "race effect" in drug analysis.
Unwanted facial hair is a common problem that is seldom discussed in the primary care setting. Although men occasionally request removal of unwanted facial hair, women most often seek help with this condition. Physicians generally neglect to address the problem if the patient does not first request help. The condition may be caused by androgen overproduction, increased sensitivity to circulating androgens, or other metabolic and endocrine disorders, and should be properly evaluated. Options for hair removal vary in efficacy, degree of discomfort, and cost. Clinical studies on the efficacy of many therapies are lacking. Short of surgical removal of the hair follicle, the only permanent treatment is electrolysis. However, the practice of electrolysis lacks standardization, and regulation of the procedure varies from state to state. Shaving, epilation, and depilation are the most commonly attempted initial options for facial hair removal. Although these methods are less expensive, they are only temporary. Laser hair removal, although better studied than most methods and more strictly regulated, has yet to be proved permanent in all patients. Eflornithine, a topical treatment, is simple to apply and has minimal side effects. By the time most patients consult a physician, they have tried several methods of hair removal. Family physicians can properly educate patients and recommend treatment for this common condition if they are armed with basic knowledge about the treatment options.
Mast cells are so widely recognized as critical effector cells in allergic disorders and other immunoglobulin E-associated acquired immune responses that it can be difficult to think of them in any other context. However, mast cells also can be important as initiators and effectors of innate immunity. In addition, mast cells that are activated during innate immune responses to pathogens, or in other contexts, can secrete products and have cellular functions with the potential to facilitate the development, amplify the magnitude or regulate the kinetics of adaptive immune responses. Thus, mast cells may influence the development, intensity and duration of adaptive immune responses that contribute to host defense, allergy and autoimmunity, rather than simply functioning as effector cells in these settings.
This review focuses on recent progress in our understanding of how mast cells can contribute to the initiation, development, expression, and regulation of acquired immune responses, both those associated with IgE and those that are apparently expressed independently of this class of Ig. We emphasize findings derived from in vivo studies in mice, particularly those employing genetic approaches to influence mast cell numbers and/or to alter or delete components of pathways that can regulate mast cell development, signaling, or function. We advance the hypothesis that mast cells not only can function as proinflammatory effector cells and drivers of tissue remodeling in established acquired immune responses, but also may contribute to the initiation and regulation of such responses. That is, we propose that mast cells can also function as immunoregulatory cells. Finally, we show that the notion that mast cells have primarily two functional configurations, off (or resting) or on (or activated for extensive mediator release), markedly oversimplifies reality. Instead, we propose that mast cells are "tunable," by both genetic and environmental factors, such that, depending on the circumstances, the cell can be positioned phenotypically to express a wide spectrum of variation in the types, kinetics, and/or magnitude of its secretory functions.
Mast cells (MCs) have recently been reported to play a pivotal role in the elicitation of inflammatory reactions that are beneficial to the host, e.g., during innate immune responses to bacteria. To explore whether MCs also contribute to wound repair, we studied experimentally induced skin wounds in MC-deficient Kit(W)/Kit(W-v) mice, normal Kit+/+ mice, and MC-reconstituted Kit(W)/Kit(W-v) mice. Wound closure was significantly impaired in the absence of MCs during the first 6 days of wound healing and histomorphometric analyses of MC degranulation at the wound edges revealed distance-dependent MC activation, i.e., MC degranulation was most prominent directly adjacent to the wound. In addition, Kit(W)/Kit(W-v) mice showed impaired extravasation and recruitment of neutrophils to the wounded areas. Notably, wound closure, extravasation, and neutrophil recruitment were found to be normal in MC-reconstituted Kit(W)/Kit(W-v) mice. Therefore, we examined whether MCs promote wound healing by releasing histamine or TNF-alpha. Interestingly, wound closure was reduced in mice treated with an H1-receptor antagonist but not after treatment with an H2-receptor antagonist or in the absence of TNF-alpha. Taken together, our findings indicate that MC activation and histamine release are required for normal cutaneous wound healing.
Neurotrophins regulate cutaneous innervation, act as growth and motility factors on structural skin cells such as keratinocytes and fibroblasts, modulate cutaneous immune function and even serve as stress mediators in skin biology. The multilayered neurotrophin interaction with skin biology through high affinity specific tyrosinekinase receptors and the Janus-faced p75 receptor, which depending on ligand and co-receptor expression can serve as a low-affinity pan-neurotrophin receptor or a high affinity proneurotrophin receptor, guaranties this neuroendocrine peptide family a central position in the control of skin homeostasis in health and disease. It is a challenging task for future research efforts to integrate our knowledge on differential neurotrophin expression patterns and signaling pathways into complex concepts of neuroendocrine tissue remodeling and pathogenetic processes. In addition, we need to improve our understanding of the role of neurotrophin processing enzymes, associated co-receptors and intracellular adaptor molecules in specific cutaneous cell populations to design precise interaction tools for research and treatment. Such tools will allow us to utilize this ancient growth factor family in the management of neurotrophin responsive pathogenetic pathways and cutaneous diseases such as neurogenic inflammation, peripheral nerve degeneration, wound healing, atopic dermatitis or psoriasis.
Hair's importance for insulation and camouflage or human communication means that hairs need to change with season, age or sexual development. Regular, regenerating hair follicle growth cycles produce new hairs which may differ in colour and/or size, e.g., beard development. Hormones of the pineal-hypothalamus-pituitary axis coordinate seasonal changes, while androgens regulate most sexual aspects with paradoxically different effects depending on body site; compare beard growth and balding! Hormones affect follicular mesenchymal-epithelial interactions altering growing time, dermal papilla size and dermal papilla cell, keratinocyte and melanocyte activity. Greater understanding of these mechanisms should improve treatments for poorly controlled hair disorders, alopecia and hirsutism.
Mast cells are best known for their potent effector functions in allergic disorders. In recent years, however, mast cells have been identified to be involved in a surprisingly complex range of immune functions that go far beyond allergies and include the development of autoimmune disorders and peripheral tolerance, and the initiation and maintenance of adaptive and innate host responses. Here, we review the key signals and effector mechanisms that have lately been identified for mast cell functions in these immune responses.
Mast cells (MCs) have recently been shown to be essential for the elicitation of efficient immune responses in murine sepsis. To explore whether MCs also contribute to the control of bacterial skin infections, we studied skin lesions induced by Pseudomonas aeruginosa (PA) in genetically MC-deficient Kit(W)/Kit(W-v) mice, normal Kit(+/+) mice, and MC-reconstituted Kit(W)/Kit(W-v) mice. PA injections resulted in strikingly (>2-fold) larger skin lesions in Kit(W)/Kit(W-v) mice than in Kit(+/+) mice, which exhibited pronounced MC degranulation at infection sites. In addition, neutrophil recruitment following PA injections and bacterial clearance from sites of infection was significantly impaired in Kit(W)/Kit(W-v) mice compared with Kit(+/+) mice. Notably, the adoptive transfer of MCs to the skin of Kit(W)/Kit(W-v) mice before PA infection resulted in normal neutrophil accumulation as well as skin lesions comparable with those in Kit(+/+) mice in both bacterial burden and size. These findings demonstrate for the first time that activated MCs are crucial for the induction of protective innate immune responses to bacterial skin infections.
Mast cells (MCs) and nerves can induce cutaneous inflammatory responses, both independently and by interacting with each other. However, little is known about the role of skin nerves and neuropeptides in the regulation of MC-mediated skin inflammation, and the contribution of MCs in neurogenic inflammation is still controversial.
The aim of this study was to investigate the effects of cutaneous sensory nerves on MC-driven inflammatory responses.
Passive cutaneous anaphylaxis, a model for type I allergic skin responses, was studied in the presence or absence of sensory nerves by using a murine model of selective cutaneous denervation.
Passive cutaneous anaphylaxis was significantly impaired in the absence of sensory nerves. This effect was not a result of an alteration of mast cell numbers in denervated skin. Moreover, IgE-mediated activation of mast cells was markedly decreased in denervated compared with normal skin. Notably, pretreatment of mice with selective antagonists of the neuropeptides substance P and/or calcitonin gene-related peptide also resulted in decreased inflammatory responses after MC activation.
These data suggest that sensory skin nerves augment MC-driven inflammatory responses by releasing neuropeptides that increase MC degranulation.