Validation of the VapoMeter, a closed unventilated chamber system to assess transepidermal water loss vs. the open chamber TewameterR

Transepidermal water loss and stratum corneum hydration in forearm versus hand palm

BACKGROUND

Skin measurements of transepidermal water loss (TEWL) and stratum corneum hydration (SCH) reflect different aspects of skin physiology. Since epidermal water loss depends on epidermal-to-air water vapor gradients, a possible quantitative relationship between TEWL and SCH may exist. This investigation's purpose was to test the possible TEWL-SCH relationship.

MATERIALS AND METHODS

SCH and TEWL were measured noninvasively on forearm and palmer thenar eminence (hand) in 40 young adults (20 males) along with total body fat percentage (FAT) via bioimpedance.

RESULTS

A significant positive nonlinear correlation (p < 0.001) was detected between SCH and TEWL in hands of the male cohort that occurred when SCH exceeded a threshold level. This threshold level was not exceeded in male or female forearms and forearms did not display a SCH-TEWL correlation. There was a weak inverse dependence of TEWL on FAT on both forearm and hand (p < 0.05), but no SCH-FAT relationship was observed. TEWL values on the forearm and hand were moderately correlated with each other (p = 0.002) but SCH values were not.

CONCLUSION

The findings clarify the relationship between forearm and palmer hydration and TEWL values, and their relationship to total body fat percentages in young healthy adults. The significant correlation between palmer stratum corneum hydration and palmer TEWL that was discovered in the male but not the female cohort suggests a threshold hydration level for which TEWL depends both on skin barrier function and stratum corneum hydration. This implies that conditions with increased SCH may in part account for elevated TEWL values.

The effect of adjuvant radiotherapy on skin biophysical properties in patients with breast cancer at risk for breast lymphedema: A prospective study

Breast cancer (BC) is the most common type of cancer among women. Radiotherapy (RT) is one of the main and primary treatment options for BC, especially in breast-conserving surgery (BCS). BC patients who underwent RT experience a wide range of symptoms, in which breast oedema and irritation of the skin take the lion's share. Breast oedema/lymphedema, which is also a prominent side effect after RT should be well determined in earlier settings due to the chronicity of lymphedema. Therefore, this study aimed to analyze the biophysical parameters of skin on the ipsilateral (IL) and contralateral (CL) sites via Tissue dielectric constant (TDC) and Transepidermal water loss (TEWL) methods in terms of oedema and skin barrier function (SBF). The following reference points before and after the RT were measured: (R1: Pectoralis muscle, R2: Upper breast, R3: Lower breast, R4: Lateral site of the thorax). A total of 24 BC patients (mean age and BMI: 52.78 ± 9.85 years and 28.42 ± 5.64 kg/m² ) were evaluated. In the IL site, the SBF was not found significant in R1-R3, whereas significantly lower SBF was observed in R4 after RT (t = -3.361, p = 0.003). A significant increase in TDC was observed in R2 at the 5.0 mm depth (t = -2.500, p = 0.02). We suggest that a longer period of follow-up should be carefully carried out to track changes in terms of SBF and oedema in the irradiated breast. The increased need for early detection of changes associated with breast lymphedema can be achievable via noninvasive, safe, cheap, and easily repeatable devices.

Development of a Nanotechnology Matrix-Based Citronella Oil Insect Repellent to Obtain a Prolonged Effect and Evaluation of the Safety and Efficacy

Mosquito-borne diseases affect millions of people worldwide each year, and the use of a topically applied insect repellent is an economically viable preventative health practice. The general objective of this work was to encapsulate citronella oil (CO) in a nanostructured lipid carrier (NLC) to formulate a topical repellent with a long duration of efficacy on the skin and a good safety profile based on minimizing skin penetration. In the studied CO, the main chemical constituents of geraniol, citronellal, and citronellol were identified and subsequently used as markers for the in vitro skin permeation testing (IVPT). An optimal NLC encapsulating CO formulation was developed and had an average particle size of 350 nm. The NLC was then formulated in combination with CO at ratios of 2:1, 1:1, and 1:2 CO:NLC-CO as oil-in-water (O/W) emulsions and compared to CO in the same O/W emulsion base (all at 10% CO in the final O/W topical formulation). The markers geraniol, citronellol, and citronellal were detected in all samples tested F1 (10% CO in O/W emulsion) and F3 (10% CO/NLC-CO 1:1 in O/W emulsion). Even the percentages of F3 markers were higher than F1. The recovery of the percentage balance (based on the total remaining on the skin surface, on the skin, and penetrated through the skin to the receptor) of geraniol, citronellol, and citronellal markers for F1 and F3 was 7.70% and 11.96%; 25.51% and 31.89%; and 5.09% and 4.40%, respectively. The nanoparticle lipid solid forms a repellent reservoir on the skin surface, releasing the active ingredients slowly through volatilization, extending the repellent action, and reducing permeation through the skin. It is possible to assume that the remaining 92.30% and 88.03%; 74.49% and 68.11%; and 94.10% and 95.60% of geraniol, citronellol, and citronellal markers of F1 and F3, respectively, were lost to evaporation. In the in vivo efficacy test carried out with the Aedes aegypti mosquito, F3 was the optimal formulation, providing the greatest repellent action compared to free oil in O/W emulsion. Thermal analysis showed that the NLC-CO raised the boiling point of the encapsulated CO compared to the free oil, suggesting that the controlled release of the CO was a possible mechanism for its prolonged effect. We concluded that the nanocarriers developed with CO were stable and provided improved mosquito-repellent efficacy with minimal skin penetration of the CO actives over 24 h. Indeed, regardless of whether the CO was applied as free oil, a 1:1 mixture of CO (pure/free oil) or NLC-CO applied in an O/W emulsion can be considered safe for topical application due to minimal skin penetration.

Effects of dietary camelina, flaxseed, and canola oil supplementation on transepidermal water loss, skin and coat health parameters, and plasma prostaglandin E2, glycosaminoglycan, and nitric oxide concentrations in healthy adult horses

Camelina oil is derived from a low-input, high-yield crop and, in comparison to many other dietary fat sources currently used in equine diets, provides a greater amount of α-linolenic acid [ALA; (n-3)], than linoleic acid [LA; (n-6)]. However, no research exists assessing the effects of feeding camelina oil to horses in contrast to other commonly used oils. The objective of this study was to compare the effect of supplementing camelina oil to that of flaxseed and canola oil supplementation, on outcomes related to skin and coat health in horses. Thirty adult horses [23 mares, 7 geldings; 14.9 years ± 5.3 years; 544 ± 66 kg body weight (BW) (mean ± SD)] underwent a 4-week wash-in period consuming hay and sunflower oil. Following the wash-in period, horses were blocked by location, age, and BW, and assigned to one of three treatment oils for 16 weeks (370 mg oil/kg BW): camelina (CAM), canola (OLA), or flaxseed (FLX) oil. Blood samples were collected and plasma prostaglandin E2 (PGE2; ELISA), nitric oxide (NO; Griess Reaction), and glycosaminoglycan (GAG; DMMB) concentrations were measured on weeks 0 (n = 30), 14 (n = 24), and 16 (n = 30). On weeks 0, 2, 4, 8, and 16, transepidermal water loss (TEWL) was measured pre- and post-acetone application using a VapoMeter (n = 26), and a 5-point-Likert scale was used to assess skin and coat characteristics on the side and rump of the horses (n = 30). All data were analyzed with repeated measures ANOVA using PROC GLIMMIX in SAS. Independent of treatment, coat color, and quality increased from baseline. There were no differences in the outcomes assessed between the horses supplemented camelina oil and those supplemented canola or flaxseed oil. These results suggest that independent of treatment, all oil supplements improved coat color and quality in horses. This provides indication that camelina oil is comparable to existing plant-based oil supplements in supporting skin and coat health and inflammation in horses.

Quantitative evaluation of skin barrier function using water evaporation time related to transepidermal water loss

BACKGROUND

Transepidermal water loss (TEWL) is often used as an index for skin barrier function. The skin barrier tester, SBT-100 (Rousette Strategy Inc), measures the TEWL, water evaporation time, and time constant by contacting the skin and diffusing water into the closing measurement chamber. However, the relationship between the TEWL and time constant has not been sufficiently investigated. This study involved analyzing the underlying measurement principle and obtaining data through two experiments.

MATERIALS AND METHODS

The TEWL and time constant were measured using SBT-100. Experiment 1 produced a simple simulation model for continuous water evaporation from the skin using a moisture-permeable film. In experiment 2, four skin sites of 43 healthy volunteers were examined from May to September 2018.

RESULTS

In experiment 1, the TEWL increased and time constant decreased, following an increase in humidity in the external environment. Both parameters demonstrated significant negative correlation (drying: ρ = -0.832, p < 0.001). For the 43 healthy volunteers who participated in experiment 2, their TEWL increased and time constant decreased in summer. For all skin measurement sites, both data demonstrated significant negative correlation (forehead: ρ = -0.909, p < 0.001; back of the left hand: ρ = -0.829, p < 0.001; left lateral elbow: ρ = -0.896, p < 0.001; left lateral malleolus: ρ = -0.865, p < 0.001).

CONCLUSION

Results indicated that the time constant is significantly correlated with TEWL. Furthermore, the time constant can be used as a parameter for evaluating skin barrier function.

Pilot study in human healthy volunteers on the use of magnetohydrodynamics in needle-free continuous glucose monitoring

The benefits of continuous glucose monitoring (CGM) in diabetes management are extensively documented. Yet, the broader adoption of CGM systems is limited by their cost and invasiveness. Current CGM devices, requiring implantation or the use of hypodermic needles, fail to offer a convenient solution. We have demonstrated that magnetohydrodynamics (MHD) is effective at extracting dermal interstitial fluid (ISF) containing glucose, without the use of needles. Here we present the first study of ISF sampling with MHD for glucose monitoring in humans. We conducted 10 glucose tolerance tests on 5 healthy volunteers and obtained a significant correlation between the concentration of glucose in ISF samples extracted with MHD and capillary blood glucose samples. Upon calibration and time lag removal, the data indicate a Mean Absolute Relative Difference (MARD) of 12.9% and Precision Absolute Relative Difference of 13.1%. In view of these results, we discuss the potential value and limitations of MHD in needle-free glucose monitoring.

Moisture retention of glycerin solutions with various concentrations: a comparative study

Various methods of evaluating a humectant's moisture retention have unique mechanisms. Hence, for designing advanced or efficient ingredients of cosmetic products, a clear understanding of differences among methods is required. The aim of this study was to analyze the moisture-retention capacity of glycerin, a common ingredient in cosmetic products. Specifically, this study applied gravimetric analysis, transepidermal water loss (TEWL) analysis, and differential scanning calorimetry (DSC) to examine the evaporation of glycerin solutions of different concentrations. The results revealed that the moisture-retention capacity of glycerin increased with the glycerin concentration from 0 to 60 wt%, and glycerin at concentration of 60-70 wt% did not exhibit weight change during the evaporation process. When the glycerin concentration exceeded 70 wt%, moisture sorption occurred in the glycerin solution. Furthermore, the results revealed a deviation between the evaporation rates measured using gravimetric analysis and those measured using TEWL analysis. However, normalizing the results of these analyses yielded the relative evaporation rates to water, which were consistent between these two analyses. DSC thermograms further confirmed the consistent results and identified two hydrated water microstructures (nonfreezable water and free water) in the glycerin solutions, which explained why the measured evaporation rate decreased with the glycerin concentration. These findings can be applied to prove the moisture-retention capacity of a humectant in cosmetic products by different measuring methods.

Devices measuring transepidermal water loss: A systematic review of measurement properties

OBJECTIVE

The objective of this review is to examine the reliability and measurement error of devices that measure transepidermal water loss (TEWL).

INTRODUCTION

TEWL is a physiological property of skin which increases when the epidermis is damaged. It is, therefore, a commonly utilised measure of skin barrier integrity. Devices measuring TEWL are available as open, semi-open or closed chamber. Studies of reliability examine the consistency of measurement, and/or responsiveness whereas measurement error scores in absolute terms the amount of error due to sources of variation.

INCLUSION CRITERIA

Studies examining the reliability and/or measurement error of TEWL measurement devices were included. Studies that only report on measurement of TEWL outcomes without examination of reliability and/or measurement error were excluded.

METHODS

The search strategy aimed to locate published and unpublished studies. Databases searched included PubMed, Embase, CINAHL and Web of Science, utilising identified keywords and limited to studies in English. Grey literature sources were searched to identify any unpublished documents. Study selection using the inclusion criteria was then assessed by two reviewers for methodological quality utilising the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) risk of bias tool to assess the reliability and measurement error of outcome measurement instruments.

RESULTS

A total of 22 devices were examined in the 38 included studies. The quality of study design was on average rated as 'Adequate' however reliability and measurement error statistical methods were on average rated as 'Doubtful'.

DISCUSSION AND CONCLUSION

TEWL measurement devices were found to demonstrate good reliability and frequently correlated with other devices. However, measurement error was highly variable but improves under in vitro conditions. Future research should consider risk of bias factors when designing studies.

Is CEES a good analog of sulfur mustard? Macroscopic aspect, histology, and molecular biology comparisons between sulfur mustard and CEES-induced skin lesions

Sulfur mustard (SM) is a chemical blistering warfare agent affecting multiple organs. SM is an ongoing chemical threat in addition to the accidental risk associated with World War I buried shells. As no specific treatments are available, only symptomatic therapies can be used. To test new medical countermeasures in standard laboratories, analogs such as 2-chloroethyl ethylsulfide (CEES) are currently used, although only a few studies compare its clinical effects with SM. In the present paper, skin lesions induced by SM and CEES are compared in terms of their macroscopic aspects, histology, and molecular biology to evaluate the pertinence of CEES as a SM analog. For this purpose, an in vivo model of CEES vapor exposure, similar to that of SM, is described in this paper. RESULTS: showed similar skin lesions with CEES and SM but with slight differences in the apparition delay and intensity of the lesions. Indeed, SM induced earlier, deeper, and stronger lesions. However, the same healing status was observed at the end of the study period (14 days). In conclusion, CEES appears a relevant analog of SM, leading to similar skin lesions. The CEES vapor exposure model therefore seems suitable for testing new medical countermeasures.

Noninvasive Objective Tools for Quantitative Assessment of Skin Scarring

Significance: Many treatments are utilized in the management of skin scarring; however, difficulties arise due to the high rates of recurrence and the identification of treatment efficacy in each patient, in particular, in the case of raised dermal scarring. Therefore, evaluation of treatments and the provision of objective scar assessment pre-therapy and post-therapy is of paramount importance to identify changes in scar characteristics using noninvasive devices. Recent Advances: There have been a number of emerging noninvasive objective quantitative devices, which assess specific scar parameters such as pliability, volume, color, perfusion, and depth. These can include three-dimensional imaging, optical coherence tomography, in vivo confocal microscopy, full-field laser perfusion imaging, and spectrophotometric intracutaneous analysis. Critical Issues: Clinical assessment and grading scales are most commonly used to assess scarring; however, there is a need for more objective quantitative measures to monitor their maturation and response to therapy. Currently, there is no consensus as to which objective measuring device is most optimal when assessing skin scarring. There is a need for a predictor tool that allows early implementation of treatment and addresses diagnosis, therapy, and prognosis. Future Directions: Validation of noninvasive objective scar assessment tools is essential as well as further development of technologies. There are currently more modalities that assess physical scar characteristics and only few that measure the physiological parameters. Therefore, the development of a technology that quantifies the metabolic and cellular activity in skin scars is necessary to allow for bespoke strategies for each patient.

Skin barrier status during dupilumab treatment in patients with severe atopic dermatitis

Background:

Atopic dermatitis (AD) is a common chronic-relapsing inflammatory skin disease hallmarked by epidermal barrier dysfunction, increased transepidermal water loss (TEWL) and decreased skin hydration. Recent findings on the T helper 2 (Th2)-driven pathogenesis of AD have led to the development of dupilumab, a monoclonal antibody directed against interleukin-4 and interleukin-13 that has been demonstrated to be effective in the treatment of moderate-to-severe AD. The effect of dupilumab on skin barrier dysfunction, however, has not yet been adequately investigated.

Objectives:

The primary endpoint of this study was to assess the status of the skin barrier in nonlesional skin of patients with severe AD treated with dupilumab, by evaluating the association between the relative variation of TEWL and the achievement of a 75% reduction of EASI (EASI75) over time.

Methods:

TEWL was measured below the antecubital fossae by means of the Vapometer® at baseline, at week 4 (T4), at week 16 (T16) and at week 32 after dupilumab starting. EASI and NRS-itch were measured at the same time points.

Results:

Seventy-eight patients with severe AD treated with dupilumab were enrolled. Median TEWL relative variation respect to baseline was significantly higher in patients who achieved EASI75 as compared with those who did not achieve EASI75 at T16 and at T32, but not at T4.

Conclusion:

During dupilumab treatment, TEWL on nonlesional skin tends to significantly improve 4 months after treatment initiation and could be a good tool for monitoring response to therapy.

Hyperhidrosis of the residual limb: a narrative review of the measurement and treatment of excess perspiration affecting individuals with amputation

BACKGROUND

Hyperhidrosis (HH) is a relatively common disorder involving excessive sweating, typically of the palms or axilla. HH can also frequently occur after limb amputation, where the remaining residual limb excessively perspires, leading to an increased risk of dermatological disorders and functional limitations, such as the inability to comfortably or safely wear a prosthesis. Although many treatments have been proposed to treat HH within the dermatology community, they are not widely known by healthcare providers typically involved in caring for individuals with acquired limb loss.

OBJECTIVES

To appraise the current state of quantitative and qualitative assessment of HH within the residual limb and examine existing and future treatment strategies for this problem.

STUDY DESIGN

Narrative Literature Review.

METHODS

A literature review focused on the assessment and treatment of excessive sweating of residual limbs.

RESULTS

There is currently no objective or subjective standard to assess or diagnose HH of the residual limb. Conventional therapies for HH do not always translate to the population of individuals with limb loss. Emerging modalities for treating HH show promise toward a permanent resolution of excess perspiration but require additional studies within people with amputation.

CONCLUSIONS

Further research is needed to quantify standard values to objectively and subjectively assess and diagnose hyperhidrosis of the residual limb. New and developing treatments for hyperhidrosis require additional studies to assess efficacy and safety in the residual limb.

Devices measuring transepidermal water loss of the skin: a systematic review protocol of measurement properties

OBJECTIVE

The objective of this review is to examine the reliability and measurement error of devices that measure transepidermal water loss.

INTRODUCTION

Transepidermal water loss is a physiological property of skin that increases when the epidermis is damaged. It is, therefore, a commonly utilized measure of skin barrier integrity. Devices measuring transepidermal water loss are available as open, semi-open, or closed chamber. Studies that examine the similarities and differences between transepidermal water loss measurement devices are available. However, there has not been a systematic review to comprehensively collate and critique these studies. The aim of this review will be to synthesize the data from these studies to aid in selection and use of transepidermal water loss measurement devices in clinical practice or research.

INCLUSION CRITERIA

Studies examining the reliability and/or measurement error of transepidermal water loss measurement devices will be included. Studies that examine a single device to demonstrate how different handling affects measurements will also be included. Studies that only report on measurement of transepidermal water loss outcomes without examination of reliability and/or measurement error will be excluded.

METHODS

The search strategy will aim to locate published and unpublished studies. Databases to be searched will include PubMed, Embase, CINAHL, and Web of Science, utilizing identified keywords and limited to studies in English. Gray literature sources will be searched to identify any unpublished documents. Study selection will adhere to the inclusion criteria and then be assessed by two reviewers for methodological quality utilizing COSMIN (COnsensus-based Standards for the selection of health status Measurement INstruments) guidelines and risk of bias tools. Extracted data will be presented in a narrative synthesis and as tables and figures to aid data presentation.

Effect of soak and smear on [14C]-hydrocortisone in vitro human skin percutaneous penetration

INTRODUCTION

'Soak and smear' method, water soaking to induce skin hydration followed by topical corticoids application suggests effectiveness in clinical dermatological practice. We investigate one possible mechanism of soaking times effect on drug partitioning and diffusion rates in skin and its proposed efficacy.

METHODS

Utilizing an in vitro flow-through diffusion system to evaluate efficacy of the 'soak and smear' method following 0.5, 8, and 20 min water soaking and [¹⁴C]-hydrocortisone topical application on human skin to probe the possibility of percutaneous penetration enhancement.

RESULTS

In water-soak groups, more [¹⁴C]-hydrocortisone was absorbed and retained in stratum corneum and epidermis, whereas, in the control (no soak) more was in the deep skin-dermis and receptor fluid. These differences between water-soak groups and the control are statistically significant (p < .05).

CONCLUSION

Effect of 'soak and smear' on skin absorption and penetration depends on interaction of individual drug's physicochemical property, stratum corneum hydration, and stratum corneum-epidermoid barrier status. Water soaking (≤ 20 min) induced skin hydration increases [¹⁴C]-hydrocortisone absorption and retention into the upper skin layer but not deep layers. This could support the proposed hypothesis of clinical dermatological treatment of hydrocortisone to local skin inflammations should the epidermis be found to be a key target for atopic dermatitis therapy.

The Addition of Tissue Stromal Vascular Fraction to Platelet-Rich Plasma Supplemented Lipofilling Does Not Improve Facial Skin Quality: A Prospective Randomized Clinical Trial

BACKGROUND

Lipofilling has become popular as a treatment to improve aging-related skin characteristics (eg, wrinkles, pigmentation spots, pores, or rosacea). Different additives such as platelet-rich plasma (PRP) or stromal vascular fraction (SVF) have been combined with lipofilling to increase the therapeutic effect of adipose-derived stromal cells (ASCs).

OBJECTIVES

The aim of this study was to examine the hypothesis that mechanically isolated SVF augments the therapeutic effect of PRP-supplemented lipofilling to improve facial skin quality.

METHODS

This prospective, double-blind, placebo-controlled, randomized trial was conducted between 2016 and 2019. In total, 28 female subjects were enrolled; 25 completed the follow-up. All patients received PRP-supplemented lipofilling with either mechanically isolated SVF or saline. SVF was isolated by fractionation of adipose tissue (tSVF). Results were evaluated by changes in skin elasticity and transepidermal water loss, changes in skin-aging-related features, ie, superficial spots, wrinkles, skin texture, pores, vascularity, and pigmentation, as well as patient satisfaction (FACE-Q), recovery, and number of complications up to 1 year postoperative.

RESULTS

The addition of tSVF to PRP-supplemented lipofilling did not improve skin elasticity, transepidermal water loss, or skin-aging-related features. No improvement in patient satisfaction with overall facial appearance or facial skin quality was seen when tSVF was added to PRP-supplemented lipofilling.

CONCLUSIONS

In comparison to PRP-supplemented lipofilling, PRP-supplemented lipofilling combined with tSVF does not improve facial skin quality or patient satisfaction in a healthy population. PRP-supplemented lipofilling combined with tSVF can be considered a safe procedure.

LEVEL OF EVIDENCE: 2

Repeatability and Reproducibility of Tear Film Evaporation Rate Measurement using a new Closed-Chamber Evaporimeter

Purpose:

This study evaluates the repeatability and reproducibility of tear film evaporation rate measurement using a commercially available handheld closed-chamber evaporimeter (VapoMeter, Delfin Technologies, Finland).

Study Design:

This was a randomized observational study, in which two visits were required. At visit 1, screening tests were performed on the participants. Subsequently, tear evaporation was measured thrice by examiner 1 (E1). The procedure was then repeated by examiner 2 (E2) at visit 2.

Methods:

40 healthy participants with no ocular diseases were recruited for this study. A closed chamber evaporimeter was used in this study (VapoMeter, Delfin Technologies, Finland). Primary investigations, including slit-lamp examination, tear production test, and ocular discomfort, were performed during the first visit for the purpose of screening.

Results:

The mean of the three measurements of tear evaporation obtained by examiner 1 at visit 1 was 19.38 ± 0.79 g/m2/h, and the mean of the three readings obtained by examiner 2 at visit 2 was 20.49 ± 0.48 g/m2/h. The average Intraclass Correlation Coefficient (ICC) among the three readings of tear evaporation was 0.84 and 0.63 with a 95% confidence interval (CI) at visits 1 and 2, respectively. A comparison of the reliability of the measurements from the two examiners revealed an ICC of 0.69 with a 95% CI.

Conclusion:

The VapoMeter provides repeatable and reproducible measurements of tear film evaporation. This study demonstrates that the VapoMeter could provide clinicians with a readily available method for rapid evaluation of tear film evaporation. By considering the significance of tear evaporation as a diagnostic tool for dry eyes, the VapoMeter may help to diagnose better and manage dry eye syndrome.

Longitudinal study of the scalp microbiome suggests coconut oil to enrich healthy scalp commensals

Dandruff is a recurrent chronic scalp disorder, affecting majority of the population worldwide. Recently a metagenomic study of the Indian scalp microbiome described an imperative role of bacterial commensals in providing essential vitamins and amino acids to the scalp. Coconut oil and its formulations are commonly applied on the scalp in several parts of the world to maintain scalp health. Thus, in this study we examined the effect of topical application of coconut oil on the scalp microbiome (bacterial and fungal) at the taxonomic and functional levels and their correlation with scalp physiological parameters. A 16-weeks-long time-course study was performed including 12-weeks of treatment and 4-weeks of relapse phase on a cohort of 140 (70 healthy and 70 dandruff) Indian women, resulting in ~ 900 metagenomic samples. After the treatment phase, an increase in the abundance of Cutibacterium acnes and Malassezia globosa in dandruff scalp was observed, which were negatively correlated to dandruff parameters. At the functional level, an enrichment of healthy scalp-related bacterial pathways, such as biotin metabolism and decrease in the fungal pathogenesis pathways was observed. The study provides novel insights on the effect of coconut oil in maintaining a healthy scalp and in modulating the scalp microbiome.

Unbearable transepidermal water loss (TEWL) experimental variability: why?

Despite the wide breadth of research, much disparity exists in transepidermal water loss (TEWL) research data-possibly due to uncontrolled experimental variables. We determined whether such experimental variables significantly impact TEWL studies and cause this disparity. An initial literature search regarding TEWL was performed to determine potential confounding variables. A subsequent search procured relevant and representative studies investigating the impact of these variables on TEWL. Variables, such as age, anatomic site, and temperature, impact TEWL and should be controlled for in TEWL studies. Other variables, such as smoking and menstrual cycle, have inconclusive results or do not provide sufficient data breadth to make a conclusion regarding its effect, if such an effect exists, on TEWL metrics. Therefore, these variables require further research to determine their potential impact on TEWL. Matching for as many experimental variables as possible may reduce the disparity in TEWL data/conclusions.

Premature infant skin barrier maturation: status at full-term corrected age

OBJECTIVE

To evaluate the effects of gestational age (GA) and postnatal age on skin barrier integrity by comparing premature infants at full-term corrected age with infants born at term.

STUDY DESIGN

Parallel comparison of chest skin in 36 premature infants with 39 full-term infants using daily measures of transepidermal water loss (TEWL), skin pH, erythema and rash, over 2 weeks.

RESULT

Chest skin pH was significantly lower for premature infants, indicating that acid mantle formation had occurred in the premature versus full-term infants. Chest TEWL was significantly higher for premature versus full-term infants over 2 weeks, suggesting that even 7-8 weeks after birth, skin integrity is poorer in premature infants.

CONCLUSION

Skin barrier properties of premature infants at adjusted full-term age differ from full-term infants, suggesting that epidermal barrier development depends on GA and time from birth. These maturational differences may influence premature infant response to topical agents.

Effect of superabsorbent polymers (SAP) and metal organic frameworks (MOF) wiping sandwich patch on human skin decontamination and detoxification in vitro

Most chemical warfare agents partition rapidly into stratum corneum (SC) and subsequently slowly diffuse through - or are retained in the membrane. Since chemicals can interact with SC components during the process, skin decontamination poses a challenging yet important problem. To address these issues, we have developed a new method in combination with wet and dry decon technologies with new materials for emergency or delayed contamination scenarios. An in vitro human skin diffusion system was employed to model various dermal exposures of radiolabeled chemical warfare simulants, followed by surface decontamination with metal organic frameworks (MOFs), super-absorbent polymers (SAP), and/or dermal decontamination gel (DDGel). All samples measured for radioactive recovery and acetylcholinesterase activity to ascertain relative decon efficacy. Results demonstrated powerful water absorption of SAP, strong catalysis of UiO-66 MOF, and decon enhancement of pre-wetting surface contaminants. SAP had no interfering interactions with MOF yet provided additional benefits as porosity and reactivity that allowed for fast liquidized chemical transportation, absorption, and degeneration. We then designed a cotton-based SAP/MOF patch that worked cooperatively in decontamination and detoxification. Together with pre-wet, SAP/MOF wipe, and DDGel applications, maximum effect was observed in early and/or extended dermal exposure, and no "wash-in" effect occurred.

Skin Physiology and its Microbiome as Factors Associated with the Recurrence of Pressure Injuries

BACKGROUND

Preventing recurrent pressure injuries (RPIs) is one of the important challenges faced in healthcare, but the risk factors of RPIs have not been fully revealed. This study aims to explore factors associated with RPIs, by focusing on skin physiology and its microbiome as local factors crucial for the health of healed tissue after pressure injury healing.

METHODS

This prospective observational study was conducted in a long-term care facility in Japan with patients whose PIs had healed within 1 month. Skin physiology was evaluated by stratum corneum (SC) hydration, pH, and transepidermal water loss. Skin bacteria was collected by tape stripping, followed by 16S ribosomal RNA-based metagenomics analysis. These parameters were evaluated every two weeks over a period of six weeks.

RESULTS

A total of 30 patients were included in this study, and 8 patients (26.7%) had an RPI within 6 weeks. In this study, significantly lower SC hydration and a higher rate of Staphylococcus species on the healed site were found in the RPI group.

DISCUSSION

A high rate of RPIs (about one in four) points out the necessity of a further care strategy on the healed PIs. Lower skin hydration and/or the increase in Staphylococcus bacteria may have a potential to be used as a biomarker for the prediction of RPIs, or may be an intervention point for the prevention of RPIs by, for example, skin cleansing with moisturizing care.

In vitro human skin percutaneous penetration: does a second topical application effect flux of first application?

INTRODUCTION

Skin care products are often utilized in conjunction with topical treatment for skin disease. However, these appears insufficient body of experimental data to advise the health care worker or patient. Examine penetration effect (hence potential for altering efficacy and toxicity) - dosing with one topical after another and how quickly such a potential phenomenon might occur.

METHODS

A marketed moisturizer applied on human skin with an in vitro diffusion system. At 1, 15, and 30 min post application, [¹⁴C]-benzoic acid dosed the same skin site for 24 h. Amounts of chemical retained in skin and permeation flux rats were measured to determine penetration effect of the prior moisturizer application.

RESULTS

Exposure of a water-enriched moisturizer before a hydrophilic chemical immediate application favors the chemical penetration, especial in 1 and 15 min moisturizer exposure groups. The enhancement effect was expressed as an earlier lag time and a rapid absorption peak when compared to related non-moisturizer control.

CONCLUSION

This experiment opens up a large door: what would be the result with many complex topical products and different tracers was used here, of varying hydrophilicity and lipophilicity. We do not wish to overgeneralize until such studies are confirmed in vivo.

A Clinical Anti-Ageing Comparative Study of 0.3 and 0.5% Retinol Serums: A Clinically Controlled Trial

BACKGROUND

Retinol influences the process of keratinization of the epidermis, which improves stratum corneum structure and reduces transepidermal water loss. It also significantly enhances mature skin by brightening hyperpigmentation and reducing the signs of photoageing. Cosmeceuticals are intended to both provide aesthetic effects for the skin and allow dermatological treatment. The aim of the study was to assess the rejuvenating effect of retinol serum on facial skin at concentrations of 0.3 and 0.5%, as well as any improvements in skin brightening and elasticity.

MATERIALS AND METHODS

Thirty-seven volunteers were included in the study, after confirming tolerance. The novel formula was applied once daily to the face for a period of 12 weeks: one retinol concentration on the left side and the other on the right. The initial study with liquid crystal formula (study vehicle) was carried out for 8 weeks on 28 volunteers. Treatment efficiency was evaluated at baseline, and 56 and 84 days following treatment using the multi probe adapter and Fotomedicus imaging system. PRIMOS was used to measure skin surface roughness. The visual analogue scale method enabled the results to be determined by 3 independent specialists.

RESULTS

Skin hyperpigmentation, unevenness, and wrinkles gradually decreased over the course of treatment, both on the left and right parts of the face. Adverse events were predominantly mild or moderate skin irritation. More frequent and more intense symptoms were observed on the left side (0.5%).

CONCLUSION

Retinol in liquid crystal formulation is safe and provides significant clinical benefits associated with unification of skin colour, overall skin tone, skin elasticity, and moisture. Regular use of retinol typically results in brightening of the skin and reduced signs of ageing. The objective findings confirmed the effectiveness of the procedures.

Behavior of 1-Deoxy-, 3-Deoxy- and N-Methyl-Ceramides in Skin Barrier Lipid Models

Ceramides (Cer) are essential components of the skin permeability barrier. To probe the role of Cer polar head groups involved in the interfacial hydrogen bonding, the N-lignoceroyl sphingosine polar head was modified by removing the hydroxyls in C-1 (1-deoxy-Cer) or C-3 positions (3-deoxy-Cer) and by N-methylation of amide group (N-Me-Cer). Multilamellar skin lipid models were prepared as equimolar mixtures of Cer, lignoceric acid and cholesterol, with 5 wt% cholesteryl sulfate. In the 1-deoxy-Cer-based models, the lipid species were separated into highly ordered domains (as found by X-ray diffraction and infrared spectroscopy) resulting in similar water loss but 4–5-fold higher permeability to model substances compared to control with natural Cer. In contrast, 3-deoxy-Cer did not change lipid chain order but promoted the formation of a well-organized structure with a 10.8 nm repeat period. Yet both lipid models comprising deoxy-Cer had similar permeabilities to all markers. N-Methylation of Cer decreased lipid chain order, led to phase separation, and improved cholesterol miscibility in the lipid membranes, resulting in 3-fold increased water loss and 10-fold increased permeability to model compounds compared to control. Thus, the C-1 and C-3 hydroxyls and amide group, which are common to all Cer subclasses, considerably affect lipid miscibility and chain order, formation of periodical nanostructures, and permeability of the skin barrier lipid models.

Effect of iron and silica nanoparticles’ size on in vitro human skin binding and penetration

This in vitro skin study determined absorption, diffusion, and binding rates of four [14C]-labeled nanoparticles (NPs): 12 nm Fe3O4, 32 nm Fe3O4@SiO2, 33 nm SiO2, and 78 nm SiO2 in each layer of human cadaver skin. In vitro microdialysis device and flow-through skin diffusion system were used to measure the binding affinity to the stratum corneum (SC) and permeability into/through skin layer of the four NPs with different physical–chemical properties, respectively, in short (30 min) and/or long (24 hours) exposures. Results show that NP size is an important factor affecting NP percutaneous absorption. The 12 nm Fe3O4 NPs reached the SC and viable epidermis; 32 nm Fe3O4@SiO2 core/shell NPs only reached SC. However, 33 nm and 78 nm silica NPs did not permeate SC. Similar patterns were observed for NP binding affinity to SC and dermatopharmacokinetic analysis using the tape stripping method. The binding affinity determination may be a useful method to efficiently screen skin penetration of NPs.

Impact of sunflower seed oil versus mustard seed oil on skin barrier function in newborns: a community-based, cluster-randomized trial

Background

Natural vegetable oils are widely used for newborn massage in many low resource settings. Animal models indicated that sunflower seed oil (SSO) can accelerate skin barrier recovery following damage, while other oils, including mustard oil (MO), may cause further skin barrier damage. The objective was to compare the effects of two SSO and MO used for routine massage on skin integrity in premature and full-term neonates.

Methods

This community-based cluster randomized controlled trial included 995 neonates assigned to full body massage with sunflower seed oil (SSO, intervention) or mustard seed oil (MO, standard practice) from July 2012–May 2014 in Sarlahi, Nepal. Skin integrity measures were evaluated over 28 days, including skin condition (erythema, rash, dryness), skin surface pH, stratum corneum (SC) cohesion/protein concentration, and transepidermal water loss (TEWL). Overall means and rates of change in these skin measures were compared between oil groups using bivariate random-effects models.

Results

500 and 495 live born neonates received repeated massage with MO and SSO, respectively. Skin pH decreased more quickly for SSO than MO in the first week of life, with a difference in mean daily reductions of 0.02 (95% CI: 0.002–0.040). Erythema, rash and dryness increased (worsened) over days 1–14 then decreased by day 28, with no significant oil group differences. TEWL increased over time, with no significant oil group differences. Gestational age did not modify the effect; the slightly faster decrease in skin pH among SSO infants was similar in magnitude between term and preterm infants.

Conclusions

Oil type may contribute to differences in skin integrity when neonates are massaged regularly. The more rapid acid mantle development observed for SSO may be protective for neonates in lower resource settings.

Trial registration

ClinicalTrials.gov (NCT01177111); registered August 6th, 2010.

A Randomized Pilot Clinical Assessment Of Three Skincare Regimens On Skin Conditions In Infants

Introduction

Few data are available on the comparison between the effects on infant skin of skin care products and those of water alone.

Patients and methods

In this single-center, evaluator-blind, parallel-group pilot study, healthy infants were randomized to near-daily washing for 12 weeks (starting in the summer and finishing in the winter months) with a mild liquid baby wash followed by use of baby lotion (wash+lotion), water followed by baby lotion (water+lotion), or water alone. Clinical and instrumental assessments of skin moisturization and barrier function were made.

Results

As expected the skin condition in all groups was affected by the change of the season. The skin of infants in all groups was mildly deteriorated (clinical grading) and with reduced moisture levels and increased barrier function. Instrumental measurements indicated that skin moisture and barrier function were better maintained in the wash+lotion and water+lotion groups than in the water-only group at week 12. Clinical assessment scores increased slightly over 12 weeks in all groups (P<0.05). At week 12, the wash+lotion group (n = 44) had significantly less change from baseline in overall skin condition and softness (lower scores) than did the water+lotion (n = 43) or water-only (n = 43) groups. The wash+lotion regimen maintained stable erythema and rash scores with lower mean values over time than in the other groups.

Conclusion

A regimen of a liquid baby wash and a baby skin lotion for 12 weeks resulted in less detrimental changes in instrumental and clinical measures of skin than using water and lotion or water alone.

The benefit of a ceramide-linoleic acid-containing moisturizer as an adjunctive therapy for a set of xerotic dermatoses

Atopic dermatitis (AD), chronic eczema, and pruritus hiemalis are a set of prevalent chronic xerotic skin disorders that share clinical features such as dryness, scales, and pruritus. A ceramide deficiency and defective epidermal functions are common in these diseases. This study was designed to assess the effect of ceramide-linoleic acid (LA-Cer)-containing moisturizer as an adjunctive therapy in the treatment of AD, chronic eczema, and pruritus hiemalis. In a 2-month study, patients with one of these three diseases were divided into two groups. The control group was treated with mometasone furoate (0.1%) cream (MF), whereas the treatment group received 0.1% MF in combination with an LA-Cer-containing moisturizer. Capacitance and transepidermal water loss were measured in normal and lesional skin, along with Eczema Assessment Severity Index and pruritus scores at Weeks 0, 2, 4, and 8. The results showed that tropical applications of an LA-Cer-containing moisturizer in combination with a topical glucocorticoid accelerated the reestablishment of epidermal permeability barrier and the amelioration of pruritus in patients with AD and pruritus hiemalis. However, it did not provide the same effect for chronic eczema. Thus, the efficacy of this combination therapy for this set of xerotic disorders requires further evaluation.

Simultaneous Measurements of Structure and Water Permeability in an Isolated Human Skin Stratum Corneum Sheet

Stratum corneum (SC), the outermost layer of human skin, acts as an intelligent physicochemical interface between the inside and the outside of our body. To make clear the relationship between structure and physical barrier properties of SC, we developed a method that enables us to simultaneously acquire X-ray diffraction (XD) patterns and transepidermal water loss (TEWL) values using a spread SC sheet isolated from human skin. The synchrotron X-ray was incident on the SC sheet surface at an angle of 45° to avoid interference between the two kinds of measurements. Detailed comparison between XD and TEWL data suggested that the thermal behavior of water permeability is closely related to the thermal expansion of the lattice spacings of the hexagonal phases above 40 °C and to the existence ratio of the orthorhombic phase below 40 °C. Thus, the new method we developed can give useful information on the mechanism of water permeation in SC without ambiguity caused by separate measurements of structure and water permeability with different samples.

Review of Modern Techniques for the Assessment of Skin Hydration

Skin hydration is a complex process that influences the physical and mechanical properties of skin. Various technologies have emerged over the years to assess this parameter, with the current standard being electrical probe-based instruments. Nevertheless, their inability to provide detailed information has prompted the use of sophisticated spectroscopic and imaging methodologies, which are capable of in-depth skin analysis that includes structural and composition details. Modern imaging and spectroscopic techniques have transformed skin research in the dermatological and cosmetics disciplines, and are now commonly employed in conjunction with traditional methods for comprehensive assessment of both healthy and pathological skin. This article reviews current techniques employed in measuring skin hydration, and gives an account on their principle of operation and applications in skin-related research.

Comparative study of transepidermal water loss in patients with and without hyperhidrosis by closed-chamber measurer in an air-conditioned environment

Objective

To evaluate the difference in transepidermal water loss in patients diagnosed with hyperhidrosis and healthy subjects, in an air-conditioned environment.

Methods

Twenty patients diagnosed with hyperhidrosis and 20 healthy subjects were subjected to quantitative assessment using a closed-chamber device, in six previously established sites.

Results

The measurements showed different transepidermal water loss values for healthy subjects and patients with hyperhidrosis, especially in the hands and feet. In the Control Group, the median for the hands was 46.4g/m²/hour (p25: 36.0; p75: 57.6), while in the Hyperhidrosis Group, the median was 123.5g/m²/hour (p25: 54.3; p75: 161.2) – p<0.001. For the feet, the Control Group had a median of 41.5g/m²/hour (p25: 31.3; p75: 63.5) and the Hyperhidrosis Group, 61.2g/m²/hour (p25: 32.3; p75: 117) – p<0.02. Measurements of the axillas also showed differences. In the Control Group, the median was 14.8g/m²/hour (p25: 11.8; p75: 19.0) and, in the Hyperhidrosis Group, 83.5g/m²/hour (p25: 29.5; p75: 161.7) – p<0.001.

Conclusion

Measuring transepidermal water loss is sufficient for diagnosis and follow-up of patients with hyperhidrosis.

Comparison of Healthy and Dandruff Scalp Microbiome Reveals the Role of Commensals in Scalp Health

Several scalp microbiome studies from different populations have revealed the association of dandruff with bacterial and fungal dysbiosis. However, the functional role of scalp microbiota in scalp disorders and health remains scarcely explored. Here, we examined the bacterial and fungal diversity of the scalp microbiome and their potential functional role in the healthy and dandruff scalp of 140 Indian women. Propionibacterium acnes and Staphylococcus epidermidis emerged as the core bacterial species, where the former was associated with a healthy scalp and the latter with dandruff scalp. Along with the commonly occurring Malassezia species (M. restricta and M. globosa) on the scalp, a strikingly high association of dandruff with yet uncharacterized Malassezia species was observed in the core mycobiome. Functional analysis showed that the fungal microbiome was enriched in pathways majorly implicated in cell-host adhesion in the dandruff scalp, while the bacterial microbiome showed a conspicuous enrichment of pathways related to the synthesis and metabolism of amino acids, biotin, and other B-vitamins, which are reported as essential nutrients for hair growth. A systematic measurement of scalp clinical and physiological parameters was also carried out, which showed significant correlations with the microbiome and their associated functional pathways. The results point toward a new potential role of bacterial commensals in maintaining the scalp nutrient homoeostasis and highlights an important and yet unknown role of the scalp microbiome, similar to the gut microbiome. This study, therefore, provides new perspectives on the better understanding of the pathophysiology of dandruff.

Preclinical assessment of safety and efficacy of intravenous delivery of autologous adipose-derived regenerative cells (ADRCs) in the treatment of severe thermal burns using a porcine model

OBJECTIVE

A number of studies have reported that application of autologous adipose-derived cell populations leads to improved outcome in different preclinical models of thermal burn injury. However, these studies were limited to assessment of relatively small injuries amounting to only ∼2% of total body surface area (TBSA) in which the complications associated with large burns (e.g.: systemic inflammation and the need for fluid resuscitation) are absent. In anticipation of translating this approach to a clinical trial in which these complications would be present we applied a preclinical model that more closely resembles a patient with large thermal burn injury requiring skin grafting. Thus, the present study used a porcine model to investigate safety and efficacy of intravenous delivery of ADRCs in the treatment of a complex burn injury comprising ∼20% TBSA and including both moderately deep (44%) partial and full thickness burns, and the injury associated with skin graft harvest.

METHODS

Two pairs of full thickness and partial thickness burns involving in total ∼20% TBSA were created on the back of Yorkshire pigs (n=15). Three days post-burn, full thickness wounds were excised and grafted with a 3:1 meshed autologous split thickness skin graft (STSG). Partial thickness wounds were not treated other than with dressings. Animals were then randomized to receive intravenous delivery of ADRCs (n=8) or vehicle control (n=7). Safety was assessed by monitoring systemic parameters (blood gases, hematology, and clinical chemistry) throughout the course of the study. Wound healing for both types of burn wound and for the skin graft donor sites was followed for 18days using wound imaging, histology, and trans-epidermal water loss (TEWL; skin barrier function assessment).

RESULTS

No serious adverse events related to ADRC infusion were noted in any of the animals. Delivery of ADRCs appeared to be safe with none of the systemic safety parameters worsened compared to the control group. TEWL and histological analyses revealed that ADRC treatment was associated with significantly accelerated healing of skin graft (27.1% vs. 1.1% on Day 5 post-grafting), donor site (52.8% vs. 33.1% on Day 5 post-excision) and partial thickness burn (81.8% vs. 59.8% on Day 18 post-treatment). Data also suggested that ADRC treatment improved parameters associated with skin graft elasticity.

CONCLUSIONS

This study demonstrated that intravenous delivery of autologous ADRCs appears to be a safe and feasible approach to the treatment of large burns and supports the use of ADRCs as an adjunct therapy to skin grafting in patients with severe burns.

The revised EEMCO guidance for the in vivo measurement of water in the skin

BACKGROUND

Noninvasive quantification of stratum corneum water content is widely used in skin research and topical product development.

METHODS

The original EEMCO guidelines on measurements of skin hydration by electrical methods and transepidermal water loss (TEWL) by evaporimeter published in 1997 and 2001 have been revisited and updated with the incorporation of recently available technologies.

RESULTS

Electrical methods and open-chamber evaporimeters for measurement of TEWL are still the preferred techniques to measure the water balance in the stratum corneum. The background technology and biophysics of these instruments remain relevant and valid. However, new methods that can image surface hydration and measure depth profiles of dermal water content now available. Open-chamber measurement of TEWL has been supplemented with semiopen and closed chamber probes, which are more robust to environmental influence and therefore convenient to use and more applicable to field studies. However, closed chamber methods interfere with the evaporation of water, and the methods cannot be used for continuous monitoring. Validation of methods with respect to intra- and inter-instrument variation remains challenging. No validation standard or test phantom is available.

RESULTS AND CONCLUSIONS

The established methods for measurement of epidermal water content and TEWL have been supplemented with important new technologies including methods that allow imaging of epidermal water distribution and water depth profiles. A much more complete and sophisticated characterization of the various aspects of the dermal water barrier has been accomplished by means of today's noninvasive techniques; however, instrument standardization and validation remain a challenge.

Indicators of skin barrier integrity among newborns massaged with mustard oil in rural Nepal

OBJECTIVE

The objective of this study was to determine the skin barrier changes during postnatal month 1 among infants receiving routine mustard oil massage in the humid conditions of rural Nepal.

STUDY DESIGN

This was an observational study among 500 live-born neonates receiving mustard oil massage. Skin integrity such as erythema, rash, dryness, skin pH, stratum corneum protein concentration and transepidermal water loss was measured on days 1, 3, 7, 14 and 28.

RESULTS

Erythema and rash increased (worsened) during weeks 1 and 2, then decreased over weeks 3 and 4. Skin pH (6.1±0.5 to 5.0±0.6) and stratum corneum protein (16.6±7.9 to 13.5±5.9 μg cm^-2) decreased. Transepidermal water loss increased from 33.2±23.5 to 43.0±24.5 g m^-2 h^-1 at day 28. Skin pH and stratum corneum protein were higher for early versus late premature infants.

CONCLUSION

Premature and full-term skin condition was generally poor especially during the first 2 weeks, improving thereafter. Maturational changes were evident.

An open-label forearm-controlled pilot study to assess the effect of a proprietary emollient formulation on objective parameters of skin function of eczema-prone individuals over 14 days

Background

This study examines the efficacy of a new plant-based emollient and assesses product acceptability.

Methods

Primary efficacy endpoints were improvement in transepidermal water loss, hydration, skin elasticity and firmness, erythema, and skin roughness and smoothness as measured using the versions of Tewameter, Corneometer, Cutometer, Mexameter, and Visioscan VC98, respectively. The cream was applied twice daily by 32 participants to an area of one forearm unaffected by eczema, while the same area of the other forearm was used as a control. Measurements were taken at day 0 and day 14. Secondary endpoints assessed the acceptability of the product.

Results

At the end of 2 weeks, transepidermal water loss, hydration, skin elasticity and firmness, erythema, and skin roughness and smoothness improved. All changes were statistically significant (p<0.01). The rate of satisfaction with the emollient properties was 82%, and the rate of absorption into the skin was 88%. Results show that the emollient hydrates and repairs eczema-prone skin with high levels of acceptability.

Change in skin properties over the first 10 years of life: a cross-sectional study

This study investigated skin characteristics in healthy Chinese children aged from 1 to 10 years and compared these findings with similar measures from the child’s mothers. Children aged 1, 2, 3, 4, 5, and 10 years (n = 29–30 per age group) and the child’s mothers were enrolled in a single-visit cross-sectional study. Clinical parameters evaluated on the face, ventral forearm, and calf were softness, smoothness, erythema, edema, rash, dryness, and scaling. Instrumental evaluations included transepidermal water loss, moisture content, and water-holding capacity. The clinical evaluations indicated a general decrease in softness, smoothness, and overall skin condition with increased child age. In general, the child’s clinical scores were better than in adults. Children had a more permeable skin barrier that matured to adult values by approximately 5 years of age. Mothers had greater skin moisture than children. Clinical and instrumental measures were consistent with skin being softer and smoother and in better overall condition in younger children. As the skin matured with age, higher scores were observed. Instrumental measures demonstrated a more permeable skin barrier in younger children compared with older children and with adults.

Effects of 6-Hydroxyceramides on the Thermotropic Phase Behavior and Permeability of Model Skin Lipid Membranes

Ceramides (Cer) based on 6-hydroxysphingosine are important components of the human skin barrier, the stratum corneum. Although diminished concentrations of 6-hydroxyCer have been detected in skin diseases such as atopic dermatitis, our knowledge on these unusual sphingolipids, which have only been found in the skin, is limited. In this work, we investigate the biophysical behavior of N-lignoceroyl-6-hydroxysphingosine (Cer NH) in multilamellar lipid membranes composed of Cer/free fatty acids (FFAs) (C16-C24)/cholesterol/cholesteryl sulfate. To probe the Cer structure-activity relationships, we compared Cer NH membranes with membranes containing Cer with sphingosine (Cer NS), dihydrosphingosine, and phytosphingosine (Cer NP), all with the same acyl chain length (C24). Compared with Cer NS, 6-hydroxylation of Cer not only increased membrane water loss and permeability in a lipophilic model compound but also dramatically increased the membrane opposition to electrical current, which is proportional to the flux of ions. Infrared spectroscopy revealed that Cer hydroxylation (in either Cer NH or Cer NP) increased the main transition temperature of the membrane but prevented good Cer mixing with FFAs. X-ray powder diffraction showed not only lamellar phases with shorter periodicity upon Cer hydroxylation but also the formation of an unusually long periodicity phase (d = 10.6 nm) in Cer NH-containing membranes. Thus, 6-hydroxyCer behaves differently from sphingosine- and phytosphingosine-based Cer. In particular, the ability to form a long-periodicity lamellar phase and highly limited permeability to ions indicate the manner in which 6-hydroxylated Cer contribute to the skin barrier function.

Wash or wipe? A comparative study of skin physiological changes between water washing and wiping after skin cleaning

BACKGROUND/PURPOSE

Presently, skin-cleaning agents that claim to be removed by water or wiping alone are commercially available and have been used for the purpose of bed baths. However, there is a lack of knowledge on how water washing and wiping differently affect skin physiological functions or ceramide content. The aim of this study was to compare the effects of water washing and wiping on skin physiological functions and ceramide content.

METHODS

Three kinds of the cleaning agents with different removal techniques (ie, water washing and wiping) were used in this study. Skin physiological functions (ie, transepidermal water loss, skin hydration, and skin pH) and skin ceramide content were measured before and after seven consecutive days of the application of each cleaning agent.

RESULTS

No significant differences in skin physiological functions or ceramide content were observed between water washing and wiping.

CONCLUSION

Cleaning agents that claim to be removed by water washing or wiping do not affect skin physiological functions or ceramide content by either removal method.

Measurement of transepidermal water loss (TEWL) in cats with experimental skin barrier dysfunction using a closed chamber system

BACKGROUND

A closed chamber evaporimeter is suitable for measuring transepidermal water loss (TEWL) in cats because of the compact device size, tolerance to sudden movement and short measuring time. TEWL is a representative parameter for skin barrier dysfunction, which is one of the clinical signs of atopic dermatitis in humans and dogs. Measurement of feline TEWL has been reported, but applicability of this parameter has not been validated.

HYPOTHESIS/OBJECTIVES

The aims of this study were to determine if tape stripping is a valid experimental model in cats for studying TEWL and to determine if a closed chambered system is a suitable measurement tool for cats.

ANIMALS

Ten clinically normal cats.

METHODS

In order to evaluate variation of the measured values, TEWL was measured at the right and left side of the three clipped regions (axillae, lateral thigh and groin). Subsequently, TEWL was measured using sequential tape stripping of the stratum corneum as a model of acute barrier disruption.

RESULTS

The variations between both sides of the three regions showed no significant difference. Sequential tape stripping was associated with increasing values for TEWL.

CONCLUSIONS AND CLINICAL IMPORTANCE

Feline TEWL was shown to reflect changes in the skin barrier in an experimental model using a closed chamber system and has the potential for evaluating skin barrier function in cats with skin diseases.

Developmental Changes in Skin Barrier and Structure during the First 5 Years of Life

The structure of the stratum corneum (SC) and the corresponding skin barrier develops from before birth up to about 4 years of age. Large subject-to-subject variability within an age group requires a large population to observe trends in skin barrier properties over time. Barrier function, quantified by transepidermal water loss (TEWL) and SC thickness, was measured on the upper inner arm and dorsal forearm in subjects aged 3 months to 4 years (n = 171) and a subset of mothers (n = 44). The rate of skin surface area expansion as a function of age peaked before birth (∼90 cm2/week) and declined to a steady plateau (∼10 cm2/week) by 1 year of age. SC thickness increased and TEWL decreased, but did not reach adult values until 3-4 years of age. A better understanding of how skin hydration changes after birth suggests that barrier function may be related mechanistically to skin surface area expansion.

A systematic review of objective burn scar measurements

BACKGROUND

Problematic scarring remains a challenging aspect to address in the treatment of burns and can significantly affect the quality of life of the burn survivor. At present, there are few treatments available in the clinic to control adverse scarring, but experimental pharmacological anti-scarring strategies are now beginning to emerge. Their comparative success must be based on objective measurements of scarring, yet currently the clinical assessment of scars is not carried out systematically and is mostly based on subjective review of patients. However, several techniques and devices are being introduced that allow objective analysis of the burn scar. The aim of this article is to evaluate various objective measurement tools currently available and recommend a useful panel that is suitable for use in clinical trials of anti-scarring therapies.

METHODS

A systematic literature search was done using the Web of Science, PubMed and Cochrane databases. The identified devices were then classified and grouped according to the parameters they measured. The tools were then compared and assessed in terms of inter- and intra-rater reproducibility, ease of use and cost.

RESULTS

After duplicates were removed, 5062 articles were obtained in the search. After further screening, 157 articles which utilised objective burn scar measurement systems or tools were obtained. The scar measurement devices can be broadly classified into those measuring colour, metric variables, texture, biomechanical properties and pathophysiological disturbances.

CONCLUSIONS

Objective scar measurement tools allow the accurate and reproducible evaluation of scars, which is important for both clinical and scientific use. However, studies to evaluate their relative performance and merits of these tools are scarce, and there remain factors, such as itch and pain, which cannot be measured objectively. On reviewing the available evidence, a panel of devices for objective scar measurement is recommended consisting of the 3D cameras (Eykona/Lifeviz/Vectra H1) for surface area and volume, DSM II colorimeter for colour, Dermascan high-frequency ultrasound for scar thickness and Cutometer for skin elasticity and pliability.