[Skin quality and ways to improve skin quality]. / Hautqualität und Möglichkeiten zur Hautqualitätsverbesserung.

BACKGROUND: Skin quality has a significant impact on the perception of attractiveness. Procedures to improve skin quality, whose quality is assured, should have sufficiently documented scientific evidence of in vivo and in vitro efficacy and significant effects proven in studies. OBJECTIVES: This paper will present findings from recent studies and experience of experts on skin quality and treatments to improve skin quality. MATERIALS AND METHODS: A PubMed database search was conducted in February 2021 on the terms skin quality and minimally invasive skin quality improvement procedures. Two reviewers independently screened the titles, resulting in the selection of 30 papers. RESULTS: Hyaluronic acid (HA) is the most commonly studied agent for skin rejuvenation treatments. The efficacy and safety of the superficially injected HA products are excellently proven on the basis of current data. According to these findings, they ensure an improvement of skin quality without significant volume changes. The skin is hydrated, its elasticity increased, the skin surface smoothened, the complexion (skin redness, glow) improved and fine lines and wrinkles are reduced. They are injected intradermally and have a clinically proven effect duration of up to 12 months. CONCLUSIONS: Hyaluronic acid is outstandingly suitable for deep hydration of the skin, and its effect is long-term and safe. Natural treatment results fulfil the needs of the patients and increase the patient-practitioner relation. Superficially injected HA products are currently the criterion standard to increase skin quality.

[Topical treatment of pigmentation disorders with cosmetic and pharmaceutical agents]. / Topische Behandlung von Pigmentstörungen mit kosmetischen und pharmazeutischen Wirkstoffen.

BACKGROUND: Esthetically unattractive hyperpigmentation can occur post-inflammatory or as a result of genetic or hormonal influences, UV exposure or medication. Important parameters for the quality of topical treatments are evidence-based in vivo and in vitro efficacy as well as scientifically verified wanted and unwanted effects. OBJECTIVES: This paper will present cosmetic and pharmaceutical topical ingredients against hyperpigmentation that have been proven in scientific studies. MATERIALS AND METHODS: A search of PubMed database was performed in October 2020 using the various ingredient names, "melasma" and "hyperpigmentation." Two reviewers independently screened titles, leading to the selection of 30 papers. RESULTS: Hydroquinone, a tyrosinase inhibitor, has been used for over 40 years to treat hyperpigmentation. It is the most commonly studied agent for lightening pigment. Despite the limited evidence-based research on novel treatment approaches, several ingredients did show efficacy as depigmenting agents, including tyrosinase inhibitors, substances that increase cell turnover, and plant derivatives. CONCLUSIONS: Hydroquinone is still the gold standard for the treatment of hyperpigmentation, along with the triple therapy of hydrochinon, tretinoin, and steroids in different modifications. In summary, hyperpigmentation is best treated using a combination therapy of different approaches that includes consequent UV protection.

Polyphenols as active ingredients for cosmetic products.

Polyphenols are secondary plant metabolites with antioxidant, anti-inflammatory and anti-microbial activity. They are ubiquitously distributed in the plant kingdom; high amounts contain, for example, green tea and grape seeds. Polyphenolic extracts are attractive ingredients for cosmetics and pharmacy due to their beneficial biological properties. This review summarizes the effects of polyphenols in the context of anti-ageing activity. We have explored in vitro studies, which investigate antioxidant activity, inhibition of dermal proteases and photoprotective activity, mostly studied using dermal fibroblasts or epidermal keratinocytes cell lines. Possible negative effects of polyphenols were also discussed. Further, some physicochemical aspects, namely the possible interactions with emulsifiers and the influence of the cosmetic formulation on the skin delivery, were reported. Finally, few clinical studies, which cover the anti-ageing action of polyphenols on the skin after topical application, were reviewed.

Age-related changes in male skin: quantitative evaluation of one hundred and fifty male subjects.

BACKGROUND/PURPOSE: Modern men have changed their beauty and grooming habits, which has resulted in an increasing demand for cosmetics for men. However, very little information is available about the dermatological needs of male skin. Therefore, the aim of this present clinical study was to conduct the first systematic assessment of the skin physiology of men with special attention to lifetime changes. METHODS: A total of 150 healthy male subjects (aged 20-70 years) were selected following strict criteria, including age, sun behavior and smoking habits. Transepidermal water loss (TEWL), hydration level, sebum production and pH values were measured with worldwide-acknowledged biophysical measuring methods at the forehead, cheek, neck, volar forearm and dorsum of hand. RESULTS: TEWL and sebum production vary by localization, but generally not with increasing age, whereas stratum corneum (SC) hydration decreases significantly at the face and neck. The greatest decrease was assessed at the forehead. Skin surface pH significantly increases with aging in the face. CONCLUSION: The present study assigns for the first time systematic reference values for standardized biophysical measuring methods and localizations reflecting the skin physiology of men in relation to age. The results show that the physiology of male skin partly changes with aging. While SC hydration and skin surface pH are affected by the subject's age, TEWL and sebum production show only minor variations.

Mechanical properties of human skin in vivo: a comparative evaluation in 300 men and women.

BACKGROUND: 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. MATERIAL AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Release and in vitro skin permeation of polyphenols from cosmetic emulsions.

OBJECTIVE: Polyphenols are natural antioxidants, which can inhibit oxidative chain reactions in human skin and prevent therefore some skin diseases and premature ageing. A prerequisite of this behaviour is their permeation through the skin barrier, in particular the stratum corneum (SC). In this study, we investigated the skin permeation kinetic of polyphenols, incorporated to semisolid emulsions, and the release of polyphenols from the emulsions. METHODS: Mixtures of model substances, consisting of catechin, epigallocatechin gallate (EGCG), resveratrol, quercetin, rutin and protocatechuic acid (PCA), were formulated into o/w emulsions with different oil phase content. The in vitro experiments were carried out in Franz-type diffusion cells by means of ex vivo pig skin and a cellulose membrane. RESULTS: The increased oil content in the emulsion led to a significant decrease in initial release coefficients (K(r)), diffusion coefficients within the formulation (D(v)) and skin permeation coefficients (K(p)), respectively. The study considered the dependence of K(r) on molecular weight and lipophilicity of polyphenolics. For both more hydrophilic and more lipophilic substance groups, the values for K(r) were inverse proportional to molecular weight. For catechin, quercetin, rutin, resveratrol and PCA, a good correlation between K(p) and K(r) parameters was obtained. The most permeable substance was PCA (K(p) = 1.2·10(-3) cm h(-1)), and the least permeable was quercetin (K(p) = 1.5·10(-5) cm h(-1)). CONCLUSION: All substances could pass the SC barrier and were found mostly in the epidermis and dermis, confirming the potential of polyphenols as anti-ageing active cosmetic ingredients.

Skin physiology in men and women: in vivo evaluation of 300 people including TEWL, SC hydration, sebum content and skin surface pH.

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.

Effects of an oral contraceptive containing chlormadinone acetate and ethinylestradiol on hair and skin quality in women wishing to use hormonal contraception.

BACKGROUND: Skin and hair appearance is important to body image. Oily skin and oily, impaired hair quality, which can develop in women taking certain types of hormonal contraceptives, may cause psychosocial stress. OBJECTIVES: The aim of the current study was to investigate the effects of an oral monophasic contraceptive (0.03 mg ethinylestradiol/2 mg chlormadinone acetate) for 12 treatment cycles on the pathophysiology of oily skin and oily, impaired hair quality in healthy women. METHODS: We assessed changes in hair and skin parameters at baseline, 12, 24 and 48 weeks, in 60 women aged 18-45 years. Psychological well-being was verified by two subject self-assessments (Hair quality, Hairdex). RESULTS: Data from 31 subjects showed that treatment significantly improved sebum excretion at capillitium and forehead, and the number of terminal hairs. Visual haptic scores revealed significant decreases in capillitium seborrhoea, hair condition/density, capillitium dandruff and irritation/redness. Subject self-assessment confirmed improvements in hair quality. Treatment was well tolerated. CONCLUSION: Chlormadinone acetate in hormonal contraception provides excellent cosmetic and dermatological benefits, which can improve psychosocial well-being.

Age-related changes in skin barrier function - quantitative evaluation of 150 female subjects.

The protection against water loss and the prevention of substances and bacteria penetrating into the body rank as the most important functions of the skin. This so-called 'skin barrier function' is the natural frontier between the inner organism and the environment, and is primarily formed by the epidermis. An impairment of the skin barrier function is often found in diseased and damaged skin. An influence of ageing on skin barrier function is widely accepted, but has not been conclusively evaluated yet. Therefore, the aim of this clinical study was to assess the potential influence of ageing on skin barrier function, including transepidermal water loss (TEWL), stratum corneum hydration, sebum content and pH value. One hundred and fifty healthy women aged 18-80, divided into five age groups with 30 subjects each, were evaluated in this study. TEWL, hydration level, sebum secretion and pH value of hydro-lipid acid film were measured with worldwide acknowledged biophysical measuring methods at cheek, neck, décolleté, volar forearm and dorsum of hand. Whereas TEWL and stratum corneum hydration showed only very low correlation with subject's age, the sebum production decreased significantly with age, resulting in the lowest skin surface lipids levels measured in subjects older than 70 years. The highest skin surface pH was measured in subjects between 50 and 60 years, whereas the eldest age group had the lowest mean pH. The dorsum of the hand was the location with the highest TEWL and lowest stratum corneum hydration in all age groups. The results show that only some parameters related to skin barrier function are influenced by ageing. Whereas sebum production decreases significantly over lifetime and skin surface pH is significantly increased in menopausal woman, TEWL and stratum corneum hydration show only minor variations with ageing.

Acceleration of membrane dynamics adjacent to a wall.

The dynamics of an induced lamellar microemulsion adjacent to a planar hydrophilic surface (45 ns) were found to be three times faster compared to the bicontinuous bulk structure (133 ns). For these investigations the grazing incidence technique for neutron spin echo spectroscopy has been developed to resolve the depth dependent near surface dynamics. The observation is rationalized in terms of membrane hydrodynamics, where the flow fields reflected by the surface lead to a crossover from classical to confined fluctuations, and faster dynamics on large length scales (also known as "lubrication") are predicted.

[Antiperspirants for the therapy of focal hyperhidrosis]. / Antiperspirantien bei der Behandlung der fokalen Hyperhidrose.

In Europe often no clear distinction is made between deodorant and antiperspirant. Particularly in Germany, the labeling "deo" is used for both. Only antiperspirants are capable of influencing the activity of eccrine sweat glands. In the treatment of focal hyperhidrosis, the use of aluminum chloride solutions represents the first choice. The efficacy is well documented in a variety of studies. Subjective side effects include pruritus and - less often - irritant dermatitis, which can be treated symptomatically and usually does not require discontinuation of the treatment. Rare variants of focal hyperhidrosis like auriculotemporal syndrome, Ross syndrome and nevus sudoriferus also are suitable for treatment with topical aluminum chloride hexahydrate solutions.

[Principles of treatment and protection for sensitive skin]. / Prinzipien der Behandlung und Schutz für empfindliche Haut.

Patients with sensitive skin complain of itching, burning, pricking or stretching sensations of the skin and even pain following application of external agents or exposure to certain environmental factors. In most cases of sensitive skin the cause remains unclear and allergic contact dermatitis, toxic irritant dermatitis or contact urticaria can be diagnosed only in a few patients. After exclusion of known exogenous or endogenous causes patients should be informed on the characteristics of sensitive skin. Potential irritating substances and procedures should be extensively avoided or utilized cautiously.

[Anti-aging creams. What really helps?]. / Antifaltencremes. Was hilft wirklich?

As youth and perception of beauty are considered to be of great importance, an increasing number of new cosmeceuticals have been developed in recent years. This article will describe new, evidence-based ingredients against skin-aging; in particular antioxidants (e.g. vitamin C, niacinamide, different polyphenols and flavonoids) and cell regulators (e.g. retinol, different peptides and growth factors. Important parameters for the quality of cosmetics and cosmeceuticals are evidence-based in-vivo and in-vitro efficacy as well as scientifically approved wanted and unwanted effects.

Near-surface structure of a bicontinuous microemulsion with a transition region.

The lamellar ordering of bicontinuous microemulsions adjacent to a planar hydrophilic wall is investigated experimentally by grazing-incidence small-angle neutron scattering and theoretically by computer simulations. It is shown that precise depth information in neutron scattering can be obtained by tuning the scattering length density of the overall microemulsion. Neutron reflectometry completes the characterization. The nucleation of a lamellar phase at the wall is observed, and a perforated lamellar transition region is identified at the lamellar-microemulsion interface. The thickness of the lamellar region is about 400 Å, which corresponds to two bilayers.

[Axillary hyperhidrosis--efficacy and tolerability of an aluminium chloride antiperspirant. Prospective evaluation on 20 patients with idiopathic axillary hyperhidrosis]. / Hyperhidrosis axillaris--Effektivität und Verträglichkeit eines aluminiumchloridhaltigen Antiperspirants. Prospektive Evaluation an 20 Patienten mit idiopathischer Hyperhidrosis axillaris.

BACKGROUND: The purpose of this study was to evaluate the efficacy and tolerability of aluminium chloride gel for treatment of axillary hyperhidrosis. PATIENTS AND METHODS: A total of 20 patients aged 22-38 (mean age: 26.9+/-4.3) with idiopathic axillary hyperhidrosis were included and treated with an antiperspirant (Sweat-off, Sweat-off GmbH, Hügelsheim). Study duration was 42 days. Treatment efficacy was evaluated clinically, as well as by starch-iodine test, gravimetric analysis and evaluation of the skin surface pH. RESULTS: After treatment there was a significant clinical improvement accompanied by significant qualitative and quantitative reduction of sweat as well as a significant reduction of skin surface pH. Except for slight skin irritation in 6 patients, there were no other side effects. Patient satisfaction improved markedly during the study. CONCLUSION: Treatment of axillary hyperhidrosis with aluminium chloride is an effective, safe and inexpensive treatment modality.

[Use of biophysical techniques to evaluate the physiologic effects of injected hyaluronic acid]. / Einsatz biophysikalischer Messverfahren zur Untersuchung der hautphysiologischen Wirkung injizierbarer Hyaluronsäure.

BACKGROUND: To evaluate the effects of intradermal injection of native hyaluronic acid on physiology of aged skin using bioengineering methods. PATIENTS AND METHODS: 10 female patients aged 44-69 were included. Study duration was 24 weeks. Each patient received 3 treatments (at week 0, 2 and 4) with native hyaluronic acid (Hyalsystem Merz Pharmaceuticals, Frankfurt/Main, Germany) and 4 examinations (week 0, 4, 12 and 24). Biophysical properties assessed were skin elasticity and surface roughness, as well as skin thickness and density. RESULTS: Skin elasticity increased while skin surface roughness was reduced. High frequency ultrasound revealed an increase of skin thickness, whereas skin density decreased during treatment and slightly increased above baseline at week 24. CONCLUSION: The evaluation of the effects of an intradermal injection of hyaluronic acid on aged skin showed an improvement of skin elasticity and skin surface roughness.

Effect of fluid intake on skin physiology: distinct differences between drinking mineral water and tap water.

It is generally stated that drinking plenty of water has a positive influence on skin condition. However, there is no published scientific study that has investigated this matter. The aim of our exploratory 'before-after' study was to evaluate the in vivo influence of drinking more than 2 L of mineral water or ordinary tap water per day on skin physiology. Ninety-three healthy subjects were included in our prospective study. After an initial run-in phase of 2 weeks to monitor individual drinking habits, subjects had to drink 2.25 L day(-1) of either mineral water (n = 53) or tap water (n = 40) for 4 weeks. Bioengineering in vivo measurements on the volar forearm included sonographic evaluation of skin thickness and density, determination of skin surface pH, assessment of skin surface morphology, and measurement of finger circumference. Eighty-six subjects completed the study. In the mineral water group measurements revealed a statistically significant decrease in skin density. Skin thickness increased slightly, albeit not at a statistically significant level. However, when separately analysing those individuals from the mineral water group, who had routinely drunken comparably little before the start of the study, their skin thickness increased at a statistically significant level. Skin surface pH remained almost unchanged in the physiologically optimal range. In the tap water group, skin density increased significantly, while skin thickness decreased significantly. Skin surface pH decreased at a statistically significant level. While in the mineral water group finger circumference decreased significantly, measurements in the tap water group revealed a statistically significant increase. Objective skin surface morphology did not change in any group. In summary, drinking more than 2 L of water per day can have a significant impact on skin physiology. The exact effects within the skin seem to differ depending on the nature of the water ingested. Randomized, controlled, double-blind follow-up trials are warranted to confirm the findings of our exploratory pilot study.