EEMCO guidance for the assessment of stratum corneum hydration: electrical methods

Biomonitoring of hand and forearm transepidermal water loss and skin pH among nursing apprentices

BACKGROUND

Measurements of transepidermal water loss (TEWL) and stratum corneum (SC) pH can help indicate work-related skin barrier damage, but sensitivity to confounding personal and ambient factors limits their potential as biomonitoring tools.

OBJECTIVES

To evaluate the difference between hand and forearm skin barrier conditions as a tool for early recognition of workers with occupational contact dermatitis.

PARTICIPANTS AND METHODS

The participants were nursing apprentices (N = 238, median age 19 years) from Zagreb, Croatia. They filled out a questionnaire based on the Nordic Occupational Skin Questionnaire, underwent a clinical examination of skin on the hands, and were evaluated for their TEWL and SC pH on the dorsum of the hand and volar part of the forearm.

RESULTS

We found that the difference between hand and forearm TEWL values (ΔTEWL) greater than 7 g/m2/h, or >50%, or the difference in SC ΔpH >0.50, predicted visible skin changes found on clinical examination. However, only the association with ΔpH >0.50 retained statistical significance when controlled for sex, age, ambient temperature, and relative humidity in a multiple regression model.

CONCLUSIONS

The difference between hand and forearm SC pH values is suggested as a reliable biomonitoring tool in recognition of damaged skin barrier conditions in occupational settings.

Extracts from Wheat, Maize, and Sunflower Waste as Natural Raw Materials for Cosmetics: Value-Added Products Reaching Sustainability Goals

Agricultural waste is underutilized, and sometimes burning them has a negative impact on the environment and human health. This research investigates the untapped potential of extracts from maize, wheat and sunflower waste as natural materials for cutaneous, specifically, cosmetic application. The possibility of incorporating lipid and ethanol extracts from wheat, maize, and sunflower into creams was investigated together with their potential contribution to the structural and functional properties of the topical formulations. Results of the physicochemical characterization show that investigated extracts can be successfully incorporated into creams with satisfactory stability. All extracts showed a desirable safety profile and good antimicrobial activity against various microorganisms. Lipid extracts have proven to be promising structural ingredients of the oil phase, contributing to the spreadability, occlusivity, and emollient effect. Ethanol extracts influenced washability and stickiness of the formulation and could be considered as prospective ingredients in self-preserving formulations. The extracts affected the sensory properties of the creams, mainly the smell and color. These results suggest that the extracts from wheat, maize, and sunflower waste could be used as multifunctional natural ingredients for cosmetic formulations which can replace less sustainable raw materials. This also represents a valorization of waste and is in line with broader sustainability goals.

Skin Barrier Function Assessment: Electrical Impedance Spectroscopy Is Less Influenced by Daily Routine Activities Than Transepidermal Water Loss

BACKGROUND

Skin barrier function assessment is commonly done by measuring transepidermal water loss (TEWL). An important limitation of this method is the influence of intrinsic and extrinsic factors. Electrical impedance spectroscopy (EIS) is a lesser-established method for skin barrier function assessment. Some influential factors have been described, but no guidelines exist regarding the standardization of these measurements.

OBJECTIVE

To evaluate the effect size of daily routine activities on TEWL and EIS, as well as their correlation with age and anatomical differences.

METHODS

Healthy participants (n=31) were stratified into three age groups (18-29, 30-49, and ≥50 years). In a climate-controlled room, EIS and TEWL measurements were performed on the left and right volar forearm and abdomen.

RESULTS

Body cream application decreased TEWL and EIS values after 15 and 90 minutes. Skin washing decreased TEWL for 15 minutes and EIS values for at least 90 minutes. TEWL was increased 5 minutes after moderate to intense exercise. Coffee intake increased TEWL on the abdomen after 60 minutes. TEWL and EIS values did not correlate with participants' age and no anatomical differences were observed. No correlation was observed between TEWL and EIS.

CONCLUSION

Body cream application and skin washing should be avoided at least 90 minutes prior to measurements of TEWL and EIS. Exercise and coffee intake should also be avoided prior to TEWL measurements. EIS may be a promising tool for skin barrier function assessment as it is less affected by daily routine activities than TEWL.

Effects of a leave-on product on the strength of the dermoepidermal junction: An exploratory, intraindividual, randomized controlled trial in older adults with dry skin

Background and Aims

Skin aging is associated with dry skin and a decrease of the strength of the dermoepidermal adhesion, which increases the risk for lacerations (skin tears). Application of leave-on products improves dry skin and seems to reduce skin tear incidence. The aim of this study was to measure the effects of a humectant containing leave-on product on the strength of the dermoepidermal junction in older adult participants with dry skin.

Methods

A randomized controlled trial using a split body design was conducted. One forearm was randomly selected and treated with a lipophilic leave-on product containing 5% urea for 8 weeks. The other forearm was the control. The parameters stratum corneum hydration (SCH), transepidermal water loss, pH, roughness, epidermal thickness and skin stiffness were measured at the baseline, Weeks 4 and 8. At Week 8, suction blisters were created and time to blistering was measured. Blister roofs and interstitial fluid were analyzed for Interleukin-1α, 6 and 8.

Results

Twelve participants were included. After 8 weeks treatment, SCH was higher (median difference 11.6 AU), and the overall dry skin score (median difference -1) and median roughness (Rz difference -12.2 µm) were lower compared to the control arms. The median group difference for Interleukin-1α was -452 fg/µg total protein (TP) in the blister roofs and -2.2 fg/µg TP in the blister fluids. The median time to blister formation was 7.7 min higher compared to the control arms.

Conclusion

The regular application of humectant containing leave-on products improves dry skin and seems to lower inflammation and contribute to the strengthening of the dermoepidermal adhesion. This partly explains how the use of topical leave-on products helps to prevent skin tears.

Efficacy and Safety of an Autologous Micrografting Procedure for Management of Striae Distensae in Women

INTRODUCTION

Striae distensae (SD), or stretch marks, are a common skin problem having a psychological impact and cosmetic concern, especially for women, in whom the prevalence is higher than in men. This study assessed the efficacy and safety of a single autologous micrografting treatment (AMT®) using Rigenera® technology for the management of SD.

METHODS

This single-centre study included 10 healthy women between 24 and 65 years of age, with Fitzpatrick-Goldman skin types I-IV, who had visible SD in glutes/thighs. Each subject acted as their own control. The treatment procedure (microneedling + AMT) and the control procedure (no treatment) were performed on contralateral sides of the glutes/thighs, targeting matched and paired SD. Microneedling was carried out using Dermapen®, equipped with 32 needle heads set at 1.5 mm needle length. The AMT procedure involved extracting biopsies from the mastoid hair zone with a 2.5-mm dermal punch, followed by disaggregation of the biopsies in a physiological saline solution using the Rigeneracons. The disaggregated micrografts were then intradermally injected using 30G 4-mm needles, maintaining a distance of 1 cm between injection points, covering the entire marked treatment region.

RESULTS

In the treated area, at 3 months post-procedure compared to pre-procedure, the following changes were observed, all with statistical significance (P ≤ 0.05): (a) significant reductions in skin roughness (Ra, - 15.9%; Rz, - 22.6%), skin luminance (- 2.0%), and blue-green color distribution (- 10.6%); (b) significant increases in skin microcirculation maximum value (+ 240.1%), skin hydration (+ 71.2%), skin elasticity (+ 216.5%), skin density (+ 34.3%), skin thickness (+ 26.0%), and hypodermis thickness (+ 29.9%). Furthermore, for each of the aforementioned parameters, there was a significantly greater improvement observed with the AMT procedure compared with microneedling at 3 months (all P ≤ 0.05).

CONCLUSION

The AMT procedure using Rigenera technology resulted in an noticeable improvement in the SD appearance after 3 months in healthy women.

Enhancing skin health and safety in aged care (SKINCARE trial): A cluster-randomised pragmatic trial

BACKGROUND

Older nursing home residents are prone to develop different skin conditions at the same time, including xerosis cutis, skin tears, pressure ulcers, incontinence-associated dermatitis or intertrigo. Guidelines and recommendations mainly address these skin conditions separately. The overall aim of this study was to measure the effects of the implementation of a skincare and prevention package.

TRIAL DESIGN

A two-arm cluster-randomised controlled trial was conducted.

METHODS

In nursing homes being assigned to the intervention group, an evidence-based and structured skincare and prevention programme was implemented for six months. Nursing home residents in the control group received standard care as usual. Blinded dermatologists conducted head-to-toe skin assessments, and the researchers assessed skin barrier parameters including stratum corneum hydration and transepidermal water loss at the upper and lower extremities after three and six months. Outcomes included the cumulative incidence of incontinence-associated dermatitis, skin tears, pressure ulcers and intertrigo, and were presented as intention-to-treat and per protocol analysis. Skin dryness and resident-reported outcomes (pain, itch, quality of life) were assessed.

RESULTS

A random sample of 17 nursing homes in the federal state of Berlin, Germany, was drawn and randomised in intervention (n = 9) and control groups (n = 8). In total, 165 participants were allocated to the intervention, and 149 participants were allocated to the control group. The cumulative incidence of skin tears (19.2 %, 95 % CI 12.8-27.8), pressure ulcers (13.6 %, 95 % CI 8.1-21.9) and intertrigo (27.0 %, 95 % CI 18.4-37.7) was lower in the intervention compared to the control group, with cumulative incidences of 27.2 % (95 % CI 19.3-36.9) for skin tears, 16.9 % (95 % CI 10.6-25.9) for pressure ulcer, and 37.8 % (95 % CI 27.5-49.4) for intertrigo. The incidence of incontinence-associated dermatitis was higher in the intervention group (26.3 %, 95 % CI 17.9-36.8) compared to the control group (23.1 %; 95 % CI 14.6-34.5). Mean skin dryness was lower in the intervention group but showed variation. The impact on pain, itch, and quality of life was trivial.

CONCLUSIONS

The present study results indicate that the implementation of tailored and evidence-based nursing routines improves skin health and safety in residential long-term care. Evidence suggests that multiple adverse skin conditions can be prevented by regular skin assessments and individually tailored skincare routines. Positive effects on skin dryness were observed, but skin physiology parameters did not indicate changes of the skin barrier function.

TRIAL REGISTRATION

This study is registered at the German Clinical Trials Register (registration number: DRKS00015680; date of registration: January 29th, 2019) and ClinicalTrials.gov (NCT03824886; date of registration: January 31st, 2019).

Evaluation of the effect of several moisturizing creams using the low frequency electrical susceptance approach

Moisturizers are cosmetic compounds designed to increase the moisture content of the skin. There are many types of these products in the market making it difficult for consumers to select the most effective moisturizer according to their age and gender. Hence, the aim of this study was to evaluate the effects of different moisturizers on skin hydration as well as to figure out any dependencies of the effects of these products on age or gender-related differences. We investigated the short-term moisturizing effects of five different skin moisturizers on 60 participants by using a low frequency electrical instrument. Skin surface susceptance was recorded and compared before and after the application of moisturizers. Statistically significant differences were observed in the moisturizing effect among different types of products. However, with respect to gender and age differences, there were insignificant differences in the effects of the moisturizers. Results of this study suggest that some types of moisturizers that exist in the markets are not as effective as required, which calls for a further evaluation of the moisturizers before entering markets and offering them for sale. In addition, findings suggest that gender or age differences are perhaps not important to consider in the application of moisturizers.

The prevalence and severity of dry skin and related skin care in older adult residents in institutional long-term care: A cross-sectional study

OBJECTIVES

To identify possible factors associated with different severities of xerosis cutis and to describe possible associations between (skin) care dependency and application of moisturizers.

DESIGN

Cross-sectional study using baseline data from a cluster-randomized controlled trial. Demographic and health characteristics, skin physiological measurements, functional abilities and application of moisturizers were compared between the participants with mild and severe dry skin. Frequency of moisturization were also compared based on the participants' skin care dependency.

RESULTS

The more distal the body area, the more severe xerosis were observed. There were no or minor differences between the groups, except for the stratum corneum hydration and skin surface pH. Participants with severe xerosis received moisturizers less often. Skin care dependent residents received moisturizers frequently.

CONCLUSION

There is under-application regarding xerosis cutis treatment in long-term care. Skin care provided by nurses, in adequate frequencies, might be helpful compared to skin care performed by the residents themselves.

Changes in the AGE/Macrophage/TNF-α Pathway Affect Skin Dryness during KK-Ay/Tajcl Mice Aging

Skin dryness associated with type 2 diabetes worsens with age; however, the underlying mechanisms remain unclear. Herein, we investigated the effects of aging on skin dryness using a type 2 diabetes mice model. Specific pathogen-free KK-Ay/TaJcl mice of different ages (10, 27, 40, and 50 weeks) were used in this study. The results confirmed that skin dryness worsens with age. Furthermore, increased levels of advanced glycation end products (AGE), prostaglandin E2 (PGE2), and tumor necrosis factor (TNF)-α, along with an increased expression of the major AGE receptor (RAGE), an increased macrophage number, and decreased collagen expression were observed in the skin of aged KK-Ay/TaJcl mice. In conclusion, dry skin conditions worsen with age in diabetic mice, and the AGE/RAGE/PGE2 and TNF-α pathways play an important role in exacerbating skin dryness during aging in these mice.

Effects of impermeable and semipermeable glove materials on resolution of inflammation and epidermal barrier impairment after experimental skin irritation

BACKGROUND

Semipermeable membranes might be suitable for glove liners or comfort gloves in individuals with irritant contact dermatitis (ICD).

OBJECTIVES

To evaluate the effects of different glove materials on inflammation and epidermal barrier impairment after experimental skin irritation.

METHODS

Nine test areas on the volar forearms of 24 healthy volunteers were irritated with sodium lauryl sulfate (1%) and afterward covered for 6 days (6 or 8 h/day) with semipermeable Sympatex (SYM), vinyl (OCC), combinations of vinyl with Sympatex (SYM/OCC) or cotton (COT/OCC), or left uncovered (CON). Up to day 10, measurements of transepidermal water loss (TEWL), erythema (a*), skin humidity (SH) and visual scoring (VS) were applied.

RESULTS

No significant differences in skin parameters were found between COT/OCC and SYM/OCC as well as between each of the combinations and CON. SYM, COT/OCC and SYM/OCC led to better results for most skin parameters than OCC alone.

CONCLUSIONS

Occlusive material has a negative impact on skin barrier recovery and inflammation after skin irritation whereas SYM is not inferior to uncovered areas indicating good tolerability. Altogether, the data suggest that SYM is a useful alternative to COT as material for glove liners and comfort gloves in ICD patients.

Effectiveness of a Skin Care Program With a Cream Containing Ceramide C and a Personalized Training for Secondary Prevention of Hand Contact Dermatitis

Background/Objectives: The aim of our study was to investigate the effectiveness of personalized training on skin protection associated with the regular use of ceramide-containing cream (CC) versus other creams (OC) for improving hand contact dermatitis. Methods: We performed a double-center randomized trial that enrolled workers with hand dermatitis. All workers received personalized training. The intervention was 3 times per day application of the study emollient. The control arm used an emollient of choice without ceramide, as needed. The primary outcome was improvement in hand dermatitis at 1 and 3 months of follow-up. Results: In total, 102 patients with hand dermatitis were enrolled in this study. Improvement in dermatitis was found in 40%, 52.5%, 50%, and 63% of OC and CC, at the first and second follow-ups, respectively. The use of CC was significantly associated with an improvement in dermatitis (odds ratios 2.6; 95% confidence intervals 1.30-5.2), analyzed using generalized equation estimation during the follow-up. Conclusion: Our study demonstrated that an educational personalized intervention could improve the signs and symptoms in patients with hand dermatitis, and the use of a CC resulted in a significantly better outcome during the 3 months of follow-up.

Wireless, Soft Sensors of Skin Hydration with Designs Optimized for Rapid, Accurate Diagnostics of Dermatological Health

Accurate measurements of skin hydration are of great interest to dermatological science and clinical practice. This parameter serves as a relevant surrogate of skin barrier function, a key representative benchmark for overall skin health. The skin hydration sensor (SHS) is a soft, skin-interfaced wireless system that exploits a thermal measurement method, as an alternative to conventional impedance-based hand-held probes. This study presents multiple strategies for maximizing the sensitivity and reliability of this previously reported SHS platform. An in-depth analysis of the thermal physics of the measurement process serves as the basis for structural optimizations of the electronics and the interface to the skin. Additional engineering advances eliminate variabilities associated with manual use of the device and with protocols for the measurement. The cumulative effect is an improvement in sensitivity by 135% and in repeatability by 36% over previously reported results. Pilot trials on more than 200 patients in a dermatology clinic validate the practical utility of the sensor for fast, reliable measurements.

Atopic Dermatitis and Water: Is There an Optimum Water Intake Level for Improving Atopic Skin?

Water is a vital nutrient with innumerable functions for every living cell. The functions of human skin include protection against dehydration of the body. Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease that presents with dry skin, erythematous and eczematous lesions, and lichenification. This paper discusses the question of whether extra water intake in children with AD affects skin hydration and the skin barrier function. Among the methods used to treat dry skin, topical leave-on products are the first-line treatment, intended to improve hydration and the skin barrier function. The effectiveness of adequate water intake as a measure to treat dry skin is still under debate. Normal skin hydration increases with dietary water intake, particularly in those with prior lower water consumption. Skin dryness in AD is instrumental to the itch and inflammation cycle, contributing to barrier impairment and aggravating disease severity and flares. Certain emollients provide significant hydration to AD skin, with relief of dryness and reduction in barrier impairment, disease severity, and flares. Further investigations are needed to evaluate the optimum water intake levels in children with AD, as important questions remain unanswered, namely, does oral hydration provide relief of skin dryness and reduce barrier impairment, disease severity, and flares; is there any additional benefit from using mineral or thermal spring water; or is there a need to specifically study the fluid/water intake in children with AD and food allergy (FA) restrictions?

Towards a modern approach to traditional use of Helichrysum italicum in dermatological conditions: In vivo testing supercritical extract on artificially irritated skin

ETHNOPHARMACOLOGICAL RELEVANCE

Helichrysum italicum has been widely used in traditional medicine to treat allergies, colds, cough, skin, liver and gallbladder disorders, inflammation, infections, and sleeplessness. Furthermore, it possesses considerable wound healing and skin protective properties, documented by several in vivo studies performed on animals. However, there is a lack of experimental evidence supporting its potential as a topical agent tested by human clinical trials.

AIM OF THE STUDY

The study aimed to investigate the skin protective activity of cotton gauze and polypropylene non-woven fabric, impregnated with H. italicum extract by the integrated supercritical CO₂ extraction-supercritical solvent impregnation process.

MATERIALS AND METHODS

The integrated process of supercritical CO₂ extraction of H. italicum and the impregnation of cotton gauze and polypropylene non-woven fabric was performed under 350 bar and 40 °C with and without the addition of ethanol as a cosolvent. Impregnated textile materials were tested in vivo for their bioactivity on irritated human skin. Randomized in vivo studies performed involved assays of both safety and efficacy of the impregnated textiles. The effects were evaluated using the in vivo non-invasive biophysical measurements of the following skin parameters: electrical capacitance, transepidermal water loss, melanin index, erythema index, and skin pH.

RESULTS

Both cotton gauze and polypropylene non-woven fabric were impregnated with H. italicum extracts under supercritical conditions with considerable values of the impregnation yield (1.97%-4.25%). The addition of ethanol as a cosolvent during the process caused significant changes in the incorporated extracts' impregnation yield and chemical profile. Both impregnated textile materials were safe, evaluated by their testing on the human skin with no cause of any irritation and redness. However, efficacy studies revealed that polypropylene non-woven fabric impregnated with H. italicum extract with ethanol as a cosolvent, possessed significantly greater potential for skin protection than the other investigated samples.

CONCLUSIONS

The present study demonstrated the feasibility of the combined supercritical extraction and impregnation process in developing materials for topical application based on H. italicum extract. The results of in vivo studies performed on human volunteers confirmed the suitability of H. italicum active components to be a part of human skin protective preparations because of their ability to maintain the skin unimpaired. Traditionally claimed applications as a medicinal plant capable of regenerating skin have been scientifically proven, in addition to employing green technology in obtaining the impregnated materials with a broad spectrum of utilization.

Analysis of clinical presentations, lip transepidermal water loss and associated dermatological conditions in patients with chronic cheilitis

Chronic cheilitis (CC) is a spectrum of inflammatory changes of unknown etiology that affect the vermilion of the lips. This study aimed to describe the epidemiology, clinical presentations and risk factors of CC. Patients with CC were recruited from the National Clinical Research Center for Oral Disease of China. A convenience sample of inhabitants who live in the same geographical region were recruited as the control group. The lip skin transepidermal water loss (TEWL) and capacitance of CC patients were compared with that of age- and gender-matched controls. Our results demonstrated that of the 109 patients with CC, 72 (66.1%; 95% CI: 57.0-75.1%) were female. The common clinical presentations of CC consisted of desquamation (n = 99; 90.8%), and/or chapping (n = 81; 74.3%), and/or pruritus (n = 64; 58.7%). Multivariable analysis showed that allergic dermatologic diseases (P < 0.001; OR: 4.5; 95% CI: 2.4-8.4), anemia (P = 0.001; OR: 3.3; 95% CI: 1.5-7.5), and indoor/outdoor alternate working environment (P < 0.001; OR: 2.1; 95% CI: 1.5-2.8) were the significant risk factors for CC. The mean lip skin TEWL was found to be significantly higher, while the capacitance was lower in CC patients compared to that of control individuals. This study provides insights into the etiopathogenesis of CC and may help clinicians to identify the most effective management strategies.

A comprehensive comparison of facial skin hydration based on capacitance and conductance measurements in Chinese women

OBJECTIVES

The aim of this study was to compare the data of conductance and capacitance measurements of facial skin hydration and to evaluate and discuss the advantages and disadvantages of the different approaches.

METHODS

We measured skin capacitance (Corneometer® CM 825) and skin conductance (Skicon-200EX®) on 30 pre-defined facial sites of 125 Chinese women, resulting in 3750 readings per device. The data were analysed and compared, and continuous colour maps were generated on a 3D avatar for capacitance, conductance, relative difference (Δ%) and correlation (R-value) by interpolating between the individual readings and converting the values to colours. This visualization allows a better interpretation of the results.

RESULTS

The complexity of facial skin hydration is revealed by this approach. The similarities and discrepancies in the facial hydration maps are clearly apparent. Due to the superiority of the Skicon in measuring high hydration levels, differences in skin hydration were evident on the forehead compared with the Corneometer maps, which may be related to the more superficial measurement of the Skicon within the stratum corneum. Conversely, a greater understanding of the complexity of facial skin hydration in the nasolabial fold was obvious when using the Corneometer. The best congruence between the instruments was found at two specific but separated facial areas, one around the inner eye region and the other one on a line between the nasolabial sulcus and the oblique, lateral jaw. Interestingly, the data were not normally distributed for both instruments and they had opposite skews. All facial clusters were statistically different from each other (p < 0.001), except the cheek and jaw for the Skicon. Larger than expected percentage coefficients of variance were found for the Corneometer on some facial sites that might be explainable by differences in stratum corneum physiology and biochemistry. Corneometer values of 48 AU and Skicon values of 132 μS were taken as the cutoff for normally hydrated facial skin.

CONCLUSIONS

Both devices have their advantages and disadvantages suggesting that bio-instrumental measurement of skin hydration is actually more complicated than commonly thought and that the different facial zones and the use of multiple instrumentation have not been adequately considered.

Impacts of Skin Eccrine Glands on the Measured Values of Transepidermal Water Loss

Transepidermal water loss (TEWL) is widely used to assess and quantify skin insensible water loss to assess skin's barrier function integrity. Low TEWL values are normally indicative of intact skin and a healthy functional barrier, whereas an increased TEWL reveals a disturbed or disrupted skin barrier. Because most skin sites at which these measurements are made have eccrine glands present, the contribution of the sweat gland activity to these measurements is variable and, in most cases, unknown. The separation between the contribution of water loss that is reflective of the skin barrier integrity versus that contributed via eccrine activation is not easy and is made more difficult since both components increase with increasing skin and environmental temperature. Endogenous factors that impact eccrine sweat gland activity include sympathetic nervous system activity, emotional stress, physical activity, eccrine gland density, and age. Exogenous factors that impact eccrine gland activity include ambient temperature and humidity and the climate where one resides. The aforementioned variables impact eccrine gland activity positively or negatively and therefore alter TEWL values accordingly. Although it may be theoretically possible to control all these factors, the difficulty in doing so results in only a few being controlled during most TEWL measurements. Such confounding processes may have impacted historical TEWL reference ranges and values previously reported. Thus, the impact of eccrine activation on standardly measured TEWL values is at this juncture unclear and may be a component contributing to some reported variability in TEWL values. To help clarify the issues, a literature review was conducted to investigate and summarize relevant prior research efforts and outcomes with respect to ways to consider eccrine activity in TEWL measurements and estimate the contribution of eccrine gland activity to TEWL values. Online databases such as Excerpta Medica Database (EMBASE), Public/Publisher Medline (PubMed), Elton B. Stephans Company (EBSCO), Google Scholar, and Wiley Online Library were searched with "transepidermal water loss" or "TEWL" in the title combined with "eccrine glands" or "sweat" anywhere in the text. The present findings indicate a multiplicity of biological and environmental variables impacting eccrine gland activity and thereby potentially affecting measured TEWL values. Even if laboratory conditions adhere to various guidelines and recommendations, it is not yet possible to separate the eccrine activation component from the parameter of true interest in the assessment of the skin's physiological barrier function except for full gland deactivation. The amount that such eccrine gland activation impacts the measured value of TEWL is generally not determined using currently available methods and the only sure way to eliminate a confounding effect is to inactivate the glands during such TEWL measurements. Because such eccrine gland deactivating approach is not usually desirable or even possible, other approaches would be recommended. One would be the development of a measuring device that could distinguish between the component of TEWL that is associated with the skin barrier function and the other that is attributable to sweat gland activation. Further research and development along these lines appear warranted.

Relationships of pain-causing substances with dry skin and effects of zaltoprofen on alleviation of symptoms in arthritis model mice

Skin dryness is a symptom of rheumatoid arthritis (RA). However, the mechanisms through which dry skin is induced in RA are unclear. Accordingly, in this study, we characterized substances related to pruritus and pain and then evaluated whether oral administration of zaltoprofen (ZLT) alleviated the symptom of dry skin induced by RA in model mice. DBA/1JJmsSlc collagen-induced arthritis model mice were treated with ZLT, and transepidermal water loss (TEWL), capacitance, and inflammation-, pruritus-, and pain-related markers were assessed. Our findings demonstrated that arthritis model mice treated with ZLT exhibited suppression of increases in TEWL and decreases in capacitance. Furthermore, ZLT also blocked the increase in mast cell numbers, substance P expression, and cyclo-oxygenase-2 expression in the skin and prevented enhancement of plasma levels of thymic stromal lymphopoietin, tumor necrosis factor-α, interleukin-6, histamine, and bradykinin. No changes in plasma levels of corticosterone or reactive oxygen species or skin levels of glucocorticoid receptor were observed in ZLT-treated arthritis model mice. Overall, these findings suggested that patients with RA may benefit from biopharmacy to alleviate joint symptoms and nonsteroidal anti-inflammatory drugs for pain relief and alleviation of skin symptoms.

Effect of celecoxib administration on the skin of 40-week-old mice

Various side effects associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in analgesia have been reported. Among the NSAIDs, celecoxib has fewer side effects and is often used in therapeutic applications. However, the effect of celecoxib on aged skin is unknown. In this study, we investigated the effects of celecoxib administration on the skin of aged mice. We analyzed a 40-week-old mouse model and a 10-week-old mice as the control group. The animals were orally administered celecoxib for four consecutive days and then killed and dissected the day after the last dose. In aged mice treated with celecoxib, the water content of the stratum corneum, which is one of the markers of dry skin, was lower than that in the control and young mice groups. In addition, serum hyaluronic acid, creatinine, and inflammatory cytokines in the collected blood samples of aged mice were elevated compared to those in other mice groups, suggesting the onset of acute renal injury. Therefore, it was considered that acute renal injury occurred from the administration of celecoxib to aged mice, whereas dry skin developed by the promotion of inflammatory cytokine secretion and release into the bloodstream in this group.

Microinjections with hyaluronic acid in combination with glycerol: How do they influence biophysical viscoelastic skin properties?

BACKGROUND

Skin quality improvement with hyaluronic acid microinjections is increasing as a clinical treatment indication and as a scientific issue. This present study assessed changes in biomechanical viscoelastic skin properties after microinjections with the skin quality booster CPM-HA20G (Belotero Revive).

MATERIALS AND METHODS

Fifteen subjects have been randomized in a 2:1 ratio to receive either three treatments (total 3 ml per side) or a single-dose treatment (total 1.5 ml per side) with CPM-HA20G at dermal level into the lower cheeks via microinjections. Treatments were provided 4 weeks apart. Biophysical measurements were performed describing the viscoelastic skin properties and the underlying skin structure. The measurements were performed before injection (week 0) and on follow-up visits 4, 8, 16, 24, and 36 weeks after the last injection treatment.

RESULTS

One (p = 0.028) as well as three (p = 0.003) consecutive treatments with CPM-HA20G improved statistically significant skin firmness (R0). For the multiple-treatment group improved significant differences were observed for skin fatigue (R3; p = 0.007) and skin density (p = 0.017) with stable skin thickness levels (p > 0.05), too. There were zero-to-weak correlations between skin thickness and biomechanical skin properties (R0, rs  = 0.084; R3, rs  = 0.093).

CONCLUSION

Overall, microinjections with CPM-HA20G improved biomechanical viscoelastic skin properties with a stronger and more pronounced effect in the multiple-treatment group. The observed changes may explain some of the skin quality improvements observed after treatment with CPM-HA20G.

The Use of Intact Fish Skin as a Novel Treatment Method for Deep Dermal Burns Following Enzymatic Debridement: A Retrospective Case-Control Study

BACKGROUND

The optimal therapy for deep burn wounds is based on the early debridement of necrotic tissue followed by wound coverage to avoid a systemic inflammatory response and optimize scar-free healing. The outcomes are affected by available resources and underlying patient factors, which represent challenges in burn care and suboptimal outcomes. In this study, we aimed to determine optimal burn-wound management using enzymatic debridement (NexoBrid™, MediWound Germany GmbH, Rüsselsheim, Germany) and intact fish skin (Kerecis® Omega3 Wound, Isafjordur, Iceland).

METHODS

In this retrospective case series, 12 patients with superficial or deep dermal burn wounds were treated with enzymatic debridement followed by fish skin, Suprathel® (PolyMedics Innovations GmbH, Denkendorf, Germany), or a split-thickness skin graft (STSG). Patients' outcomes regarding healing and scar quality were collected objectively and subjectively for 12 months after the burn injury.

RESULTS

Wounds treated with fish skin demonstrated accelerated wound healing, a significantly higher water-storage capacity, and better pain relief. Furthermore, improved functional and cosmetic outcomes, such as elasticity, skin thickness, and pigmentation, were demonstrated. The pain and itch expressed as POSAS scores (Patient and Observer Scar Assessment Scale) for fish skin decreased compared to those for wounds managed with an STSG or Suprathel. Importantly, fish skin-treated wounds had significantly improved sebum production and skin elasticity than those treated with Suprathel but showed no significant superiority compared to STSG-treated wounds.

CONCLUSIONS

Enzymatic debridement in combination with intact fish skin grafts resulted in the faster healing of burn wounds and better functional and aesthetic outcomes than split-thickness skin grafts and Suprathel treatment.

Depth-dependent hydration dynamics in human skin: Vehicle-controlled efficacy assessment of a functional 10% urea plus NMF moisturizer by near-infrared confocal spectroscopic imaging (KOSIM IR) and capacitance method complemented by volunteer perception

BACKGROUND

Stratum corneum (SC) hydration is vital for the optimal maintenance and appearance of healthy skin. In this context, we evaluated the efficacy of an NMF-enriched moisturizer containing 10% urea on different aspects of SC hydration of dry skin.

MATERIAL AND METHODS

In two clinical studies, the hydration efficacy of the moisturizer in comparison to its vehicle was investigated. In the first study, 42 subjects applied the moisturizer and the vehicle to one lower leg each. Thirty minutes and 24 h after this single treatment, SC hydration was measured by corneometry. Volunteers also rated skin moisturization and evaluated product properties. In the second study, 27 subjects each treated one forearm twice daily for 2 weeks with the moisturizer and the vehicle. Then, depth-resolved water-absorption spectra were measured by near-infrared confocal spectroscopic imaging (KOSIM IR).

RESULTS

The moisturizer exerted a superior hydrating effect compared to the vehicle. KOSIM IR measurements show that, compared to the vehicle, the moisturizer significantly improved the water gradient in the SC from the surface to a depth of 15 μm. Moreover, the moisturizer received high acceptance ratings from the volunteers and was preferred to the vehicle.

CONCLUSION

The humectants applied in the investigated moisturizer improved SC water content in total and as a function of depth. The combination of depth-resolved data (KOSIM IR) with classical corneometry provides an integrated concept in the measurement of skin hydration, rendering both methods complementary. These findings were in line with the volunteers` self-assessments of the moisturizer properties that are relevant to treatment adherence.

Development and Evaluation of an In Silico Dermal Absorption Model Relevant for Children

The higher skin surface area to body weight ratio in children and the prematurity of skin in neonates may lead to higher chemical exposure as compared to adults. The objectives of this study were: (i) to provide a comprehensive review of the age-dependent anatomical and physiological changes in pediatric skin, and (ii) to construct and evaluate an age-dependent pediatric dermal absorption model. A comprehensive review was conducted to gather data quantifying the differences in the anatomy and physiology of child and adult skin. Maturation functions were developed for model parameters that were found to be age-dependent. A pediatric dermal absorption model was constructed by updating a MoBi implementation of the Dancik et al. 2013 skin permeation model with these maturation functions. Using a workflow for adult-to-child model extrapolation, the predictive performance of the model was evaluated by comparing its predicted rates of flux of diamorphine, phenobarbital and buprenorphine against experimental observations using neonatal skin. For diamorphine and phenobarbital, the model provided reasonable predictions. The ratios of predicted:observed flux in neonates for diamorphine ranged from 0.55 to 1.40. For phenobarbital, the ratios ranged from 0.93 to 1.26. For buprenorphine, the model showed acceptable predictive performance. Overall, the physiologically based pediatric dermal absorption model demonstrated satisfactory prediction accuracy. The prediction of dermal absorption in neonates using a model-based approach will be useful for both drug development and human health risk assessment.

Analysis of the structure and function of the epidermal barrier in patients with ichthyoses - clinical and electron microscopical investigations

BACKGROUND

Ichthyoses are pathogenetically characterised by a pronounced disorder of the epidermal barrier. Clinically, hyperkeratosis, severe scaling and erythroderma are present on the entire integument. The time-consuming therapy includes daily baths and the application of skin care products to restore the epidermal barrier.

OBJECTIVES AND METHODS

To enhance the knowledge about the structure and function of the epidermal barrier in ichthyoses, we conducted clinical, biophysical and electron microscopical measurements on 46 patients with ichthyoses, including autosomal recessive ichthyoses, keratinopathic ichthyoses, X-chromosomal recessive ichthyosis and Netherton syndrome.

RESULTS

The patients displayed a significantly decreased skin hydration along with unexpectedly low transepidermal waterloss values. Electron microscopical examinations demonstrated a severe occlusion of the epidermis by lipid remnants of skin care products in the stratum corneum. We found decreased intercellular lipid lamellae and an increased undulation of the corneocyte membrane of all ichthyoses, mostly pronounced in Netherton syndrome. The lipid profiles of ichthyoses showed decreased esterified Ω-hydroxy-sphingosine (EOS) ceramide levels.

CONCLUSIONS

The results demonstrate the extent of the epidermal barrier disruption in ichthyoses. In combination with the knowledge about pathogenetic causes, individually improved therapeutic options can be derived from our results. In the future, the analyses of the organisation of intercellular lipid lamellae and corneocyte membrane undulation will enable improved investigations of the epidermal barrier in ichthyoses and may be used to study and evaluate possible effects of topical skin preparations.

Interrelationships between Skin Structure, Function, and Microbiome of Pregnant Females and Their Newborns: Study Protocol for a Prospective Cohort Study

Background

Pregnancy leads to several skin changes, but evidence about structural and functional skin changes is scarce. Findings on skin structure and function in children in their first year reveal rapid skin maturation, but evidence indicates that in particular, water holding and transport mechanisms are different from adults. Important questions include whether maternal cutaneous properties predict infant skin condition, and if so, how. This is especially relevant for the skin's microbiome because it closely interacts with the host and is assumed to play a role in many skin diseases. Therefore, the study objective is to explore characteristics of skin and hair of pregnant women and their newborns during pregnancy and in the first six months after delivery and their associations.

Methods

The study has an observational longitudinal design. We are recruiting pregnant females between 18 and 45 years using advertisement campaigns in waiting areas of gynecologists and hospital's outpatient services. A final sample size of n = 100 women is the target. We perform noninvasive, standardized skin, hair, and skin microbiome measurements. We establish the baseline visit during pregnancy until at the latest four weeks before delivery. We schedule follow-up visits four weeks and six months after birth for mothers and their newborns. We will calculate descriptive statistical methods using frequencies and associations over time depending on scale levels of the measurements. Discussion. The majority of previous studies that have investigated infants' skin microbiome and its associations used cross-sectional designs and focused on selected characteristics in small samples. In our longitudinal study, we will characterize a broad range of individual and environmental characteristics of mothers and their newborns to evaluate interrelationships with skin parameters and their changes over time. Considering the combination of these multiple variables and levels will allow for a deeper understanding of the complex interrelationship of the newborn's skin maturation. This trial is registered with ClinicalTrials.gov (Identifier: NCT04759924).

Nutrition and Water

Water has numerous functions necessary for survival including cellular homeostasis, solvent properties for dissolving ions and solutes, thermoregulation, and transport of waste and nutrients. Despite the established beneficial role of water in skin physiology, the optimal methods for skin hydration and requirements for daily water consumption remain elusive. This review summarizes the cellular and molecular biology of skin hydration, the debate and current recommendations of daily water requirements, and the latest research on interventions to improve skin hydration by both internal and external means of water exposure. We also explore the chemical properties of water, such as the concept of water "hardness" and environmental pollutants, and their impact on skin physiology.

Indomethacin, a non-steroidal anti-inflammatory drug, induces skin dryness via PPARγ in mice

Cyclooxygenase (COX)-1-selective inhibitors have side effects such as itching and dryness of the skin. In this study, the degree of skin dryness and the onset mechanism of this condition were investigated by comparing the effects of three non-steroidal anti-inflammatory drugs (NSAIDs) in mice. Mice were orally administered either indomethacin, loxoprofen sodium, or celecoxib (n = 5 per group) once daily for four consecutive days, and blood samples as well as skin and jejunal tissues were isolated on day 5. In the mice treated with indomethacin, transepidermal water loss was significantly increased, and dry skin was observed. In addition, the expression of matrix metalloproteinase (MMP)-I, mast cells, CD163, CD23, CD21, histamine, and peroxisome proliferation-activated receptor (PPAR)γ in the skin and jejunum was increased, and the blood levels of interleukin-10 and immunoglobulin E were also increased. In contrast, the expression of collagen type I in the skin was decreased. These results show that indomethacin activates PPARγ in the skin and jejunum, changes the polarity of macrophages, increases the secretion of MMP-1 from mast cells, and decomposes collagen type I, leading to dry skin.

Skin barrier response to active chlorine hand disinfectant-An experimental study comparing skin barrier response to active chlorine hand disinfectant and alcohol-based hand rub on healthy skin and eczematous skin

BACKGROUND

Alcohol-based hand rub (ABHR) is widely used for hand disinfection in the health care sector. ABHR is, however, known to cause discomfort when applied on damaged skin emphasizing the unmet need for alternative and better tolerated types of disinfectants. Active chlorine hand disinfectants (ACHDs) are potential new candidates; however, the effect on the skin barrier function compared to ABHR remains to be assessed.

MATERIALS AND METHODS

In Study A, the forearm skin of healthy adults was repeatedly exposed to ACHD and ABHR. Skin barrier function was assessed by measurement of transepidermal water loss, electrical conductance, pH, and erythema at baseline and at follow-up after 2 days, and subjective discomfort was likewise assessed. Study B was performed in the same way; however, in order to induce an experimental irritant contact dermatitis, sodium lauryl sulfate patch tests were applied to forearms before exposure to ACHD and ABHR.

RESULTS

In both studies, the skin barrier function was unaffected after repetitive exposure to ACHD and ABHR, and with no significant differences between the products. Subjective discomfort was reported as sporadic or very mild in relation to both products.

CONCLUSION

Our results illustrate that use of ACHD does not affect the skin barrier function negatively, neither in intact skin nor in skin with experimentally induced contact dermatitis. Future studies should include real-life evaluation of skin barrier function and subjective discomfort following ACHD use in individuals with and without hand eczema.

Cotton versus medical face mask influence on skin characteristics during COVID-19 pandemic: A short-term study

BACKGROUND

In the still ongoing COVID-19 pandemic, one of the main prevention strategy remain to be the use of protective face masks. Changes in skin characteristics and dermatological problems related to wearing different types of masks have been observed. The aim of this study was to compare the short-term effects of cotton versus medical masks on skin biophysical parameters in general population.

MATERIALS AND METHODS

Twenty-eight human volunteers were enrolled and divided in cotton mask and medical mask wearing groups. We measured four skin biophysical parameters: trans-epidermal water loss (TEWL), stratum corneum hydration (SCH), skin pH, and erythema index (EI) before and 3 h after wearing masks on both uncovered and mask-wearing face area.

RESULTS

TEWL increased after 3 h on exposed skin in cotton mask group and slightly decreased in medical mask group There was an increase in SCH after 3 h of wearing protective face masks in both groups. pH of the covered skin slightly decreased while EI increased after 3 h in both groups; changes were not statistically significant. Parameters did not change significantly on uncovered skin.

CONCLUSION

There were no differences between the influence of cotton versus medical protective masks on the skin of healthy volunteers in our study. Both types of masks could be recommended for short-time protection in individuals with healthy skin during COVID-19 pandemic.

Formulation of topical acidic products and acidification of the skin - Contribution of glycolic acid

OBJECTIVE

The acidic skin pH is one of the regulating factors of skin barrier homeostasis. Topical products as extrinsic factors which influence skin pH could be used for acidification of the skin and consequent beneficial effect. To formulate stabile and safe topical emulsion product with low pH is on-going challenge and areas interesting to explore are related to the effect of acidic products on the skin pH together with development of protocols for these studies. Aim of our work was to investigate formulations of acidic topical products with glycolic acid (GA) stabilized with long chain alkyl polyglucoside emulsifier, in regard to the specific colloidal structure of the vehicle, together with effect of products with different concentration of acidic active on skin pH.

METHODS

Investigated formulations were basic vehicle and two creams with glycolic acid (concentration 2 and 10 wt%). Microstructure was investigated by polarization microscopy, Raman spectral imaging, thermal analysis and rheological measurements. Effects on the skin were assessed by measurement of biophysical skin parameters in vivo studies (5-hour, 24-hour and 7-days). In vitro screening of antimicrobial activity was performed against bacteria Staphylococcus epidermidis.

RESULTS

Polarization micrographs and Raman images have shown that GA does not disturb the specific colloidal structure. Together with rheological and thermal analysis obtained results have shown that GA in higher concentrations contributes to vehicles' lamellar structure. In 5-hour study the mean values of skin pH ranged from 3.98-4.25 and 3.89-4.10 after application of products with smaller and higher GA concentration. GA samples lowered skin surface pH to 5 and less in 24-hour and 7-day study, with stronger effect of sample with more GA. Sample with 10% of GA had significant inhibitory effect on growth of S. epidermidis in 1:1 concentration.

CONCLUSIONS

Investigated APG emulsifier could be used as a stabilizer for acidic topical products with GA which are characterized by satisfactory safety profile. Topical products induce acidification of the skin after short- and long-term application without barrier impairment or sign of irritation. Acidification of the skin depends on presence of ingredients which are proton donors and their concentrations.

Doppelblinde, randomisierte repetitive In‐vivo ‐Wirksamkeitsstudie zu kommerziellen Hautschutzprodukten gegen Natriumlaurylsulfat (SLS)

HINTERGRUND

In der Primär- und Sekundärprävention von Berufsdermatosen werden Hautschutzprodukte eingesetzt, die eine präexpositionelle Schutzwirkung aufweisen sollen. Insbesondere finden sich auf dem Markt zahlreiche Produkte, die zum Einsatz bei Feuchtarbeit ausgelobt werden. Eine objektive Qualitätsbeurteilung dieser Produkte für Anwender ist auf Grund fehlender vergleichender Wirksamkeitsstudien oft nicht möglich.

MATERIAL UND METHODIK

In einer doppelblinden, randomisierten und kontrollierten In-vivo-Studie wurden sechs kommerzielle Hautschutzexterna in einem repetitiven Irritationsmodell untersucht. Sie wurden hinsichtlich ihrer präexpositionellen Schutzwirkung vor dem durch Natriumlaurylsulfat (SLS) induzierten irritativen Kontaktekzem mittels hautphysiologischer Methoden getestet. Es wurde ein Wirkindex anhand des transepidermalen Wasserverlustes (TEWL) gemäß des Protokolls der multizentrischen Studie des Forschungsprojektes FP 275 der Deutschen Gesetzlichen Unfallversicherung DGUV berechnet.

ERGEBNISSE

Die untersuchten Externa zeigten eine Schutzwirkung gegen SLS im Vergleich zum unbehandelten Kontrollfeld, wiesen allerdings signifikante Wirkunterschiede auf. Die Auswertung der Nebenparameter Corneometrie und visueller Score erbrachte ebenfalls Unterschiede zwischen den Externa.

SCHLUSSFOLGERUNGEN

Die zwischen den untersuchten Externa festgestellten Unterschiede hinsichtlich der Wirkgüte ermöglichten eine Einteilung der Produkte, welche als Grundlage für die Auswahl geeigneter Schutzpräparate dienen kann.

Double blind randomized repetitive efficacy test of various occupational skin protection preparations against sodium lauryl sulphate

BACKGROUND

Skin protection products, formerly named as barrier creams, are being used as primary and secondary prevention measures against occupational dermatoses. Many of these cosmetic products are claimed by manufacturers to be efficacious against wet work-induced skin barrier impairment if applied prior to exposure. However, results of validated and standardized in vivo efficacy tests allowing the comparison of different products are lacking.

MATERIAL AND METHODS

Efficacy of six skin protection products against sodium lauryl sulphate-induced irritant contact dermatitis was investigated in a double blind, randomized and controlled repetitive irritation study in healthy volunteers using skin physiological methods. Transepidermal water loss (TEWL) results were used to calculate an efficacy index of protection by mathematical/statistical means according to a protocol developed in a German Statutory Accident Insurance (DGUV) multicenter study (research project FP 275).

RESULTS

All tested products had a demonstrable, protective effect against SLS compared to controls, but their relative efficacy varied significantly. Differences were also seen upon evaluation of other parameters such as corneometry and clinical irritation score (visual score).

CONCLUSIONS

Product ranking as a result of the established differences allows improved selection of appropriate skin protection products based on objective parameters, as compared to heterogenous product claims.

Effects of petrolatum, a petrolatum depositing body wash and a regular body wash on biomarkers and biophysical properties of the stratum corneum

BACKGROUND

An important trend in the personal care industry involves the development of body wash products that not only clean the skin without damage but deposit conditioning ingredients to improve skin barrier function.

OBJECTIVE

The objective of this study was to develop skin biomarker measures to quantify the treatment effects of body wash products.

METHODS

We employed analysis of structural proteins (keratin 1,10,11 and involucrin), a natural moisturizing factor (pyrrolidone carboxylic acid) and an inflammatory mediator (IL-1ra/IL-1α) from adhesive discs with dry skin grading, TEWL and capacitance measurements to compare the effects of direct application of petrolatum, a high petrolatum depositing body wash, and a regular body wash on dry leg skin in a standard leg-wash treatment protocol.

RESULTS

High depositing body wash and petrolatum had positive effects on stratum corneum barrier function as judged by biomarker analysis, biophysical measurements and skin grading compared to the regular body wash product.

CONCLUSIONS

The results clearly indicate that a combination of biomarker and biophysical property measurements is effective for determining the skin benefits of moisturizing body wash products.

Reliability and agreement of instrumental skin barrier measurements in clinical pressure ulcer prevention research

In skin and wound research the instrumental measurement of skin function is established. Despite the widespread use, empirical evidence about measurement errors is widely lacking. The aim of this study was to measure reliability and agreement of skin temperature, transepidermal water loss, epidermal hydration, and erythema at the heel and sacral skin. Four experienced researchers performed skin measurements in 15 subjects. Lowest reliability was observed for transepidermal water loss at the sacral skin (ICC (1) 0.46 (95% CI 0.00‐0.78)) and highest for skin temperature at the heel skin (ICC (1) 0.99 (95% CI 0.99‐1.00)). Lowest Standard Errors of Measurement were calculated for skin temperature measurements at the heels (0.11°C) and highest for erythema measurements at the sacral skin (26.7 arbitrary units). There was a clear association between variability of estimates and reliability coefficients. Single measurements of skin temperature, stratum corneum, and epidermal hydration at the sacral and heel skin areas can be used in clinical research and practice. Means of at least two measurements should be used for estimating transepidermal water loss and erythema. Evidence is needed to inform researchers about relative and absolute measurement errors of commonly applied instruments and measurements in skin and wound research.

Polyglycerol Ester-Based Low Energy Nanoemulsions with Red Raspberry Seed Oil and Fruit Extracts: Formulation Development toward Effective In Vitro/In Vivo Bioperformance

This study focuses on the development of biocompatible oil-in-water (O/W) nanoemulsions based on polyglycerol esters, as promising carriers for natural actives: red raspberry seed oil—RO and hydro-glycolic fruit extracts from red raspberry—RE and French oak—FE. Nanoemulsions were obtained via phase inversion composition (PIC) method at room temperature by dilution of microemulsion phase, confirmed by visual appearance, percentage of transmittance, microscopic, rheological and differential scanning calorimetry (DSC) investigations. The results have shown that the basic RO-loaded formulation could be further enriched with hydro-glycolic fruit extracts from red raspberry or French oak, while keeping a semi-transparent appearance due to the fine droplet size (Z-ave: 50 to 70 nm, PDI value ≤ 0.1). The highest antioxidant activity (~92% inhibition of the DPPH radical) was achieved in the formulation containing both lipophilic (RO) and hydrophilic antioxidants (FE), due to their synergistic effect. The nanoemulsion carrier significantly increased the selective cytotoxic effect of RO towards malignant melanoma (Fem-X) cells, compared to normal human keratinocytes (HaCaT). In vivo study on human volunteers showed satisfactory safety profiles and significant improvement in skin hydration during 2 h after application for all nanoemulsions. Therefore, polyglycerol ester-based nanoemulsions can be promoted as effective carriers for red raspberry seed oil and/or hydro-glycolic fruit extracts in topical formulations intended for skin protection and hydration.

Non-invasive assessment of urea efficacy: A review

Urea is an emollient widely used in clinical dermatology to moisturise and protect the skin. Non-invasive techniques can be useful in evaluating and quantifying the moisturising and hydrating properties of topically applied urea. Amongst these, transepidermal water loss, skin conductance and capacitance are the most widely used. Dynamic tests and mapping of skin moisturisation are additional features that can be used to evaluate the dynamics of water into the stratum corneum. Ultrasound and mechanical properties can be used to investigate the effects on skin smoothness and tone. In conclusion, urea is a fundamental ingredient of cosmetic and dermatological formulations and can have several positive effects on skin function. These can be easily investigated and monitored using non-invasive techniques measuring the stratum corneum function.

A comparison of Myribase and Doublebase gel: Does qualitative similarity of emollient products imply their direct interchangeability in everyday practice?

Emollients are acknowledged as a part of standard care in therapeutic and prevention protocols as well as a part of everyday skin care routine. When it comes to making a final decision between two emollient products, the ingredient list, that is, the formulation composition could be the determining factor. In such cases the consumer, and some healthcare providers, believe that products with the same qualitative composition (ingredient list) must have the same efficacy. In this study, we have investigated the skin hydration performance of two emollient preparations (DBG and MBG), which appear to contain the same ingredients, and hence, could be considered interchangeable in everyday practice. Our studies showed that the effects of DBG were overall superior to the ones attributed to MBG at each investigated time point (1, 2, 4, and 24 h post application) when tested on normal and dry skin. Consequently, it is shown that two apparently qualitatively identical products do not necessarily provide matching efficacy.

Seasonal variations in the skin parameters of Caucasian women from Central Europe

BACKGROUND

The human skin is greatly affected by external factors such as UV radiation (UVR), ambient temperature (T), and air humidity. These factors oscillate during the year giving rise to the seasonal variations in the skin properties. The aim of this study was to evaluate the effect of seasons, environmental T, relative and absolute humidity on the skin parameters of Caucasian women, perform a literature review and discuss the possible factors lying behind the found changes.

MATERIALS AND METHODS

We measured stratum corneum (SC) hydration, transepidermal water loss (TEWL), sebum level, erythema index, and elasticity parameters R2 and R7 on the forehead and the cheek of Caucasian women from the Czech Republic throughout the year. We also performed a non-systematic literature review focused on the seasonal variations in these skin parameters.

RESULTS

We confirmed a well-documented low SC hydration and sebum production in winter. In spring, we found the lowest TEWL (on the forehead) and the highest SC hydration but also the highest erythema index and the lowest elasticity presumably indicating skin photodamage. For most of the skin parameters, the seasonal variations probably arise due to a complex action of different factors as we extensively discussed.

CONCLUSION

The data about the seasonal variations in the skin parameters are still highly inconsistent and further studies are needed for better understanding of the normal skin changes throughout the year.

Skin hydration dynamics investigated by electrical impedance techniques in vivo and in vitro

Skin is easily accessible for transdermal drug delivery and also attractive for biomarker sampling. These applications are strongly influenced by hydration where elevated hydration generally leads to increased skin permeability. Thus, favorable transdermal delivery and extraction conditions can be easily obtained by exploiting elevated skin hydration. Here, we provide a detailed in vivo and in vitro investigation of the skin hydration dynamics using three techniques based on electrical impedance spectroscopy. Good correlation between in vivo and in vitro results is demonstrated, which implies that simple but realistic in vitro models can be used for further studies related to skin hydration (e.g., cosmetic testing). Importantly, the results show that hydration proceeds in two stages. Firstly, hydration between 5 and 10 min results in a drastic skin impedance change, which is interpreted as filling of superficial voids in skin with conducting electrolyte solution. Secondly, a subtle impedance change is observed over time, which is interpreted as leveling of the water gradient across skin leading to structural relaxation/changes of the macromolecular skin barrier components. With respect to transdermal drug delivery and extraction of biomarkers; 1 h of hydration is suggested to result in beneficial and stable conditions in terms of high skin permeability and extraction efficiency.

Characterization of female intimate hygiene practices and vulvar health: A randomized double-blind controlled trial

BACKGROUND

Inappropriate feminine hygiene practices are related to vulvar unpleasant symptoms (such as skin changes, lesions, burning, pruritus, fissures, and dyspareunia).

AIMS

We assessed the daily use effects of intimate cleansers on vulvar skin by comparing two specific products for intimate care: Saugella Hydraserum (SIS), based on natural extracts, and a standard product based on lactic acid, such as Lactacyd Feminine Hygiene (LTC). Forty healthy women were enrolled in this double-blind controlled study.

METHODS

After randomization, the cleansers were used twice daily for 30 days. The hydration level was determined using the Corneometer® CM 825, the pH using the Skin-pH-Meter PH 905® and the sebum level using the Sebumeter SM815® . Measurements were performed at baseline and on day 30 on the labia majora and labia minora.

RESULTS

Both cleansers showed a reduction in the hydration level, but this was much less evident in the SIS group (-6.3% SIS vs -23,7% LTC). The pH values of the SIS group were lower than those of the LTC group, especially on the labia minora (5.27 ± 0.08 and 5.6 ± 0.1, respectively, P = .025). The sebum increased in both groups, but in the LTC group, it was higher on the labia majora (+96.2% vs +46.8%, respectively, P = .003), while on the labia minora, it was higher in the SIS group (+24.7% vs +17.1%, respectively P = NS).

CONCLUSIONS

Both cleansers tested showed high performance for safety and tolerability on vulvar skin, but SIS showed better efficacy than LTC on some parameters.

Fabric Selection in Atopic Dermatitis: An Evidence-Based Review

BACKGROUND

Clothing fabrics interact closely with the skin to shape our cutaneous microenvironment. Cotton and silk have been traditionally recommended for patients with atopic dermatitis because of reported patient comfort. New synthetic fabrics combine anti-microbial, anti-inflammatory, moisture-wicking, and soothing properties that may augment conventional management strategies in atopic patients.

OBJECTIVE

We review existing and emerging evidence for fabric selection in patients with atopic dermatitis including cotton, wool, lyocell, silk, anionic, cellulosic/cellulose based, zinc oxide coated, citric acid coated, chitosan coated, silver coated, borage seed oil coated, ethylene vinyl, and polyurethane and offer practical suggestions for clothing and bedding choices.

METHODS

A systematic search was conducted on PubMed and EMBASE electronic databases for articles from 1 January, 1994 to 1 January, 2020. Studies were included based on the following inclusion criteria: clinical trial, published in English, and fabric as the main agent being evaluated. Case reports, case series, conference abstracts, reviews, animal studies, and duplicates were excluded. Studies were then manually screened by title, abstract, and full-text articles and selected to specifically describe the effects of fabrics in patients with atopic dermatitis. Both adult and pediatric patient studies were included.

RESULTS

There appears to be an advantage to modern fabric manufacturing and processing techniques that have created smaller diameter, smoother fibers such as super- and ultrafine merino wool and anti-microbial finishes. Traditional cotton and silk fabrics have mixed evidence in improving atopic dermatitis symptoms and severity but have shown to be generally safe. Large-diameter wool has been shown to induce itching and irritation; ultra- or superfine merino wool is non-pruritic and may be recommended as an alternative. Emerging fabrics with potential efficacy in reducing atopic dermatitis severity and Staphylococcus aureus burden include silver-coated, chitosan-coated, and cellulose-based fabrics. Zinc oxide-coated, acid-coated, polyurethane-coated, borage seed oil-coated, anionic, lyocell, and ethylene vinyl fabrics have sparse evidence and require further study before conclusions can be made.

CONCLUSIONS

Appropriate fabric selection can reduce the symptom severity and exacerbations of atopic dermatitis.

The impact of different hair-removal behaviours on the biophysical and biochemical characteristics of female axillary skin

Objective

The impact of hair removal on the biophysical and biochemical characteristics of human axillary skin is not fully understood. This study investigated the effect of different hair‐removal techniques on biophysical parameters and the concentrations of key inflammatory biomarkers in the axillae of female Thai subjects. Axillary hair was removed by shaving, plucking or waxing.

Methods

Following a 2‐week washout phase without hair removal, subjects underwent visual assessment for erythema and skin dryness in one (randomized) axilla, then, hair was removed from the axilla by shaving, plucking or waxing according to each subject’s established habit. Erythema and dryness were assessed again 30 min after hair removal, and buffer scrubs collected from depilated and non‐depilated axillae and analysed for inflammatory cytokines; after a further 48 h, erythema, dryness and post‐inflammatory hyperpigmentation (PIHP) were assessed in the depilated axilla. Biophysical assessments (skin hydration, barrier integrity, elasticity and roughness) were made in depilated and non‐depilated axillae.

Results

All three hair‐removal techniques induced an increase in axillary erythema and skin dryness. Shaving was associated with significantly less erythema (P < 0.01), but significantly greater skin dryness (P < 0.05) versus the other techniques 30 min after hair removal. There were no between‐technique differences in PIHP or biophysical parameters. Interleukins IL‐1α and IL‐1RA concentrations increased, and IL‐8 concentration decreased following hair removal by each technique.

Conclusion

This is the first study to identify the principal cytokines associated with the inflammatory process triggered by axillary hair removal. A single hair‐removal treatment did not appear to induce PIHP or further biophysical changes to the skin.

Favorable effect of creams with skimmed donkey milk encapsulated in nanoliposomes on skin physiology

The use of donkey milk has a long history in external dermal application for cosmetic and medical purposes. The encapsulation of different drugs into nanoliposomes and nutrients may have many benefits for the delivery of the targeted substance. The aim of the present study is to test creams with nanoliposomes encapsulated with skimmed donkey milk, reported in our registered patent, compared with effect of the placebo cream and the untreated skin. To investigate the effect of formulated cream, we have measured the electrical capacitance, transepidermal water loss and the skin pH value. The study included 15 healthy volunteers (11 women and 4 men). The patented creams exhibited satisfactory moisturizing properties very soon after application, while hydration was reached earlier in the spots treated with night cream. Transepidermal water loss slightly decreased only after 4 weeks of treatment in each of the spots assessed. The pH value was similar after each of the treatments. Tested creams may enhance the moisture of skin very soon after application, in this way potentially enable deeper permeation of phospholipids and essential proteins, without changing the pH. It may also contribute to additional anti-aging effects.

Short-term skin reactions following use of N95 respirators and medical masks

Background

In the context of the COVID‐19 pandemic, cases of adverse skin reactions related to the wearing of masks have been observed.

Objectives

To analyze the short‐term effects of N95 respirators and medical masks, respectively, on skin physiological properties and to report adverse skin reactions caused by the protective equipment.

Methods

This study used a randomized crossover design with repeated measurements. Twenty healthy Chinese volunteers were recruited. Skin parameters were measured on areas covered by the respective masks and on uncovered skin 2 and 4 hours after donning, and 0.5 and 1 hour after removing the masks, including skin hydration, transepidermal water loss (TEWL), erythema, pH, and sebum secretion. Adverse reactions were clinically assessed, and perceived discomfort and non‐compliance measured.

Results

Skin hydration, TEWL, and pH increased significantly with wearing the protective equipment. Erythema values increased from baseline. Sebum secretion increased both on the covered and uncovered skin with equipment‐wearing. There was no significant difference in physiological values between the two types of equipment. More adverse reactions were reported following a N95 mask use than the use of a medical mask, with a higher score of discomfort and non‐compliance.

Conclusions

This study demonstrates that skin biophysical characters change as a result of wearing a mask or respirator. N95 respirators were associated with more skin reactions than medical masks.

Combination of minimum wiping pressure and number of wipings that can remove pseudo-skin dirt: A digital image color analysis

BACKGROUND

Excessive wiping friction in skin care may lead to skin damage. Bed baths are required to remove skin dirt without affecting the skin barrier function; the wiping pressure and number of wipings that satisfy these two requirements have not been clarified. This study aimed to determine the minimum wiping pressure and number of wipings that can remove skin dirt.

MATERIALS AND METHODS

In this quasi-experimental study, 50 healthy adults received an adhesion of pseudo-oily and aqueous dirt, randomly assigned to the left and right forearms. Each participant was wiped three times with wiping pressure classified into six randomly assigned categories. The dirt removal rate was calculated by color-analyzing images captured before and after each wiping, and its dependence on the combination of wiping pressure and number of wipings was assessed using a linear mixed model.

RESULTS

The combinations achieving oily dirt removal rates of 80% or more were wiping once and pressure ≥50 mmHg, wiping twice and pressure ≥40 mmHg, and wiping thrice and pressure ≥10 mmHg. Aqueous dirt was removed almost completely by wiping once, even with pressure ≥5 mmHg.

CONCLUSION

Wiping with at least 10 mmHg or more three times can sufficiently remove both oily and aqueous dirt. Dirt removal rates with weak pressure can be made about as effective as those achieved with strong pressure by increasing the number of wipings. This result can be applied to daily nursing, home care, and long-term care health facilities.

Effects of differences in wiping pressure applied by nurses during daily bed baths on skin barrier function, cleanliness, and subjective evaluations

AIM

To clarify the actual condition and examine the effects of differences in wiping pressure applied by clinical nurses during daily bed baths on skin barrier function, cleanliness, and subjective evaluations.

METHODS

For the purposes of the present quasi-experimental interventional study, "wiping pressure" was defined as the "force applied vertically to the skin surface during bed baths." Two types of bed baths, one using ordinary wiping (pressure: 23-25 mmHg) and the other using weak wiping (pressure: 12-14 mmHg), were performed on the forearms (right and left) of 30 healthy adult men and women, and the effects on transepidermal water loss, stratum corneum hydration, cleanliness, and subjective evaluations were examined.

RESULTS

The results showed no differences between ordinary and weak wiping pressure in regard to the effects on skin barrier function and cleanliness. In terms of subjective evaluations, a significant association was seen between wiping pressure and the "sensation of having dirt removed" (P = .036). Regarding "degree of pain," some participants reported that the wiping pressure felt "slightly painful" under both conditions (ordinary: 31.1%; weak: 10.7%), while some with sensitive skin reported feeling pain even during weak wiping pressure.

CONCLUSIONS

The results of the present study suggest that skin assessments should be performed before and after bed baths, and that wiping pressure should be controlled and evaluated while considering the patient's feelings.

Stability, antioxidant activity, in vivo safety and efficacy of creams with standardized wild apple fruit extract: a comparison of conventional and biodegradable emulsifiers

OBJECTIVE

The aim of the study was in vitro and in vivo characterization of cosmetic cream with 6% of standardized wild apple fruit extract, stabilized by conventional non-ionic emulsifier-CEW, in order to determine the influence of emulsifiers (conventional vs. biodegradable) on the characteristics of creams and their effects on the skin.

METHODS

Organoleptic and physico-chemical (pH values and electrical conductivity) analysis was performed, determination of fruit acids-FAs content (using HPLC analysis) and estimation of its antioxidant activity-AA (using DPPH test) during 180 days. In vivo study included following examinations: screening of safety profile (after creams application under occlusion during 24 h at human skin); skin moisturizing potential, transepidermal water loss-TEWL, skin pH after 28 days of cream application and hypopigmentation efficacy 7 days of cream application at artificially induced skin hyperpigmentation.

RESULTS

Investigated cosmetic cream-CEW showed satisfactory organoleptic, physico-chemical characteristics, stability, FAs content (0.13%) and AA (19.25 ± 0.67 %RSC) after preparation, which remained unchanged over the study period. In vivo investigation revealed absence of skin irritation after CEW's application under occlusion. An increase of skin moisturization (after 14 days ΔEC was 18.52 ± 11.51 and after 28 days of applications 16.52 ± 9.36) during 28 day-study, with unchanged TEWL and skin pH values was shown. Decrease of melanin index was revealed, too (after 7 days ΔMI was -31.40 ± 16.50).

CONCLUSION

Cosmetic cream stabilized by conventional emulsifier showed better antioxidant potential and weaker moisturizing and hypopigmentation effects related to the cream with same composition but stabilized by biodegradable emulsifiers. Based on all mentioned above, investigated cosmetic cream might be considered for potential use as modern, stable, safe and efficient cosmetic product in the prevention and/or treatment of oxidative stress-related skin changes and/or damages, for moisturization of dry, even irritated skin as well as for lightening of hyperpigmented skin. RÉSUMÉ: OBJECTIF Le but de l'étude était la caractérisation in vitro et in vivo d'une crème cosmétique contenant 6 % d'extrait normalisé de pomme sauvage, stabilisée par un émulsifiant non ionique conventionnel-CEW, afin de déterminer l'influence des émulsifiants (conventionnels vs biodégradables) sur les caractéristiques des crèmes et les effets sur la peau. MÉTHODES: Des analyses organoleptiques et physico-chimiques (pH et conductivité électrique) ont été effectuées, la détermination de la teneur en acides de fruits et en acides gras polyinsaturés (par CLHP), et l'estimation de sa teneur en activité antioxydante (AA) (à l'aide du test DPPH) pendant 180 jours. L'étude in vivo comprenait les examens suivants : dépistage du profil d'innocuité (après application de crèmes sous occlusion pendant 24 h sur la peau humaine); potentiel d'hydratation de la peau, perte d'eau transépidermique (PETE), pH de la peau après 28 jours d'application de la crème et efficacité de l'hypopigmentation après 7 jours d'application de la crème sur une hyperpigmentation de la peau induite artificiellement. RÉSULTATS: La crème cosmétique-CEW étudiée a montré des caractéristiques organoleptiques, physico-chimiques, une stabilité, une teneur en AG (0,13 %) et en AA (19,25 ± 0,67 % RSC) satisfaisantes après préparation, qui sont demeurées inchangées au cours de la période de l'étude. L'étude in vivo a révélé l'absence d'irritation cutanée après l'application de CEW sous occlusion. Une augmentation de l'hydratation de la peau (après 14 jours de DEC était de 18,52 ± 11,51 et après 28 jours d'applications de 16,52 ± 9,36) pendant l'étude de 28 jours, avec une PETE et des valeurs de pH cutané inchangées, a été démontrée. Une diminution de l'indice de mélanine a été mise en évidence également (après 7 jours, ΔMI était de 31,40 ± 16,50).

CONCLUSION

La crème cosmétique stabilisée par un émulsifiant conventionnel a montré un meilleur potentiel antioxydant et des effets d'hydratation et d'hypopigmentation plus faibles par rapport à la crème de même composition mais stabilisée par des émulsifiants biodégradables. D'après les données précédentes, la crème cosmétique étudiée pourrait être considérée comme un produit cosmétique moderne, stable, sûr et efficace dans la prévention et/ou le traitement des changements et/ou dommages cutanés liés au stress oxydatif, pour l'hydratation de la peau sèche, voire irritée, ainsi que pour éclaircir la peau hyperpigmentée.