Racial (ethnic) differences in skin properties: the objective data

The Pharmacokinetics of Topical Finasteride 0.25% Spray in Chinese Adult Male Volunteers with Androgenic Alopecia: A Phase I Study

INTRODUCTION

This study aimed to evaluate the pharmacokinetics (PK), safety, and local tolerability of local finasteride spray (0.25% solution in HPCH, once daily, volume 200 μL) after single and multiple doses in Chinese male volunteers with androgenetic alopecia.

METHODS

Twelve male patients with androgenetic alopecia received once-daily scalp application of the solution for 7 days. Blood samples were collected at specified time points (on day 1, days 3-6, and day 7 of the trial) and plasma finasteride concentrations were determined by HPLC-MS.

RESULTS

After single-dose administration, the Cmax of finasteride was 15.2 ± 5.54 pg/mL, Tmax was 11.00 (3.00, 20.00) h, AUC0-24h was 263 ± 76.6 h·pg/mL, t1/2 was 35.3 ± 47.7 h, and CL/F was 974 ± 518 L/h. After 7 days of multiple doses, Cmax,ss was 29.7 ± 12.9 pg/mL, Tmax,ss was 8.00 (3.00, 12.00) h, AUCtau,ss was 530 ± 251 h·pg/mL, AUC0-t,ss was 790 ± 464 h·pg/mL, t1/2,ss was 22.6 ± 10.7 h, and CL/Tss was 1080 ± 658 L/h. No clinically significant adverse events occurred during the study.

CONCLUSION

Compared to single-dose administration, multiple-dose administration of finasteride resulted in a stable half-life, minimal changes in clearance rate, and approximately twofold accumulation in exposure over 7 days. Multiple-dose administration of finasteride spray was well tolerated in Chinese male volunteers with androgenetic alopecia.

Impact of Skin Tone on Skin Tolerance to Shear in the Context of Pressure Injuries: Theory and Computer Modeling

ABSTRACT

OBJECTIVE

To investigate the impact of darker skin tones on skin tolerance to shear forces in the context of pressure injuries (PIs) and explore the mechanobiological hypothesis that people with darker skin may be at an increased PI risk due to altered biomechanical skin properties resulting from a lower water content (WC) as some literature suggests.

METHODS

The authors developed a computational modeling framework simulating skin with varying Poisson ratios to represent different WC levels in the stratum corneum (SC), focusing on the effects of ethnicity and WC on mechanical stresses in superficial skin during weightbearing postures. Mechanical properties of the tissues were based on literature values. Pure compression and compression with shear were applied to the skin model.

RESULTS

A lower Poisson ratio in the SC, indicating lower WC, is associated with higher tissue stresses and more intense stress concentrations, especially under combined compression and shear loading. The initial reduction in the Poisson ratio had the most significant impact on increased tissue loading. These results support the hypothesis that the lower WC in darker skin, associated with increased transepidermal water loss, may lead to altered biomechanical behavior and increased PI risk.

CONCLUSIONS

The modeling suggests that reduced WC and increased transepidermal water loss, notably present in darker skin tones, lead to higher stress concentrations within the SC, thus elevating the PI risk. Comprehensive clinical and biomechanical data across various skin tones are needed to improve the practice of PI prevention in individuals with darker skin.

Improving research and development of wearable assistive and rehabilitation technologies: a systematic review on diversity factors

This paper analyses diversity and intersectionality aspects in the R&D of wearable assistive and rehabilitation technologies (WEARTechs). We advocate for inclusive, innovative research that we hope will help bridge the gap between laboratories and the real world and reduce disparities in healthcare and technology development. We performed a systematic literature review of the intersections between assistive technologies and diversity and conducted a thematic analysis of the diversity factors identified in the literature. In addition, we carried out a supplementary literature search on WEARTechs to discover which, if any, diversity aspects are currently being reported on. Our findings indicate that diversity has not been addressed in the field of WEARTechs. There is not sufficient knowledge to determine, which diversity-related aspects researchers must consider when evaluating the performance of any specific WEARTech device. Nor about how these can be properly addressed in the R&D process. We, therefore, provide actionable recommendations on how to integrate diversity-relevant aspects at different R&D stages. We hope that our review will help scientists rethink and reformulate approaches to the R&D of WEARTechs and build the way towards more inclusive solutions. It is our belief that this will spark innovation and enhance discovery potential in the field.

Exploring physiological differences in injury response by skin tone: A scoping review

AIM

To explore existing literature examining physiological differences in pressure ulcer response among individuals with differing skin tones.

METHODS

This was a scoping review. Articles meeting the inclusion criteria were retrieved from electronic databases including PubMed, CINAHL, Scopus, Cochrane, and EMBASE, using the keywords "pressure ulcer," "skin pigmentation," "melanin," and "risk factor." Data were extracted using a predesigned data extraction tool and analysed using a narrative synthesis.

RESULTS

Five papers met the inclusion criteria. Analysis of findings suggests there are potential mechanisms which may influence the skin's ability to withstand mechanical stress and its inflammatory response to damage among those with different skin tones; the structure of the stratum corneum, collagen density, fibroblast activity, mast cell density, and transepidermal water loss (TEWL). The stratum corneum can compromise skin resilience, while collagen density and fibroblast activity may impact skin strength and repair. Mast cells affect inflammation, which can exacerbate pressure ulcer damage, and increased TEWL in those with dark skin tones can result in lower water content in the stratum corneum, affecting hydration.Conversely, factors like melanosome size, hair follicle and hair fiber characteristics, sebaceous gland activity, vitamin D production, UVR protection, and desquamation rate, although relevant to overall skin health, may not directly affect the mechanical processes leading to pressure ulcer formation.

CONCLUSIONS

Physiological differences in skin structure may contribute to alterations in the response to pressure ulcer development among individuals with dark skin. Recognising these differences is important for targeted prevention strategies within diverse populations. However, further research is needed to explore the mechanisms underlying this association in greater detail.

A Pilot One and Two-Year Prospective, Blinded Clinical Evaluation of Efficacy, and Safety of Combined Treatment With Crosslinked Hyaluronic Acid Dermal Filler and Barbed Polydioxanone Suspension Threads for Mid-Face Contour Enhancement

INTRODUCTION

The combination of hyaluronic acid (HA) fillers and polydioxanone (PDO) thread lifting is gaining popularity for mid-face rejuvenation, especially among the Asian population. Despite the common use of these techniques, there is a paucity of long-term studies assessing their combined efficacy and safety. This study aims to evaluate the efficacy and safety of combined HA filler and PDO thread treatment for mid-face rejuvenation over a 24-month period in a Korean population.

MATERIALS AND METHODS

This prospective, blinded, single-center, open-label trial included 11 Korean subjects, aged 29-70 years, with mid-face volume loss graded 1-4 on the antero-medial cheek fullness scale. Participants were treated with crosslinked HA dermal fillers and PDO threads. Assessments were conducted using the Global Aesthetic Improvement Scale (GAIS), investigator-led clinical evaluations, and volumetric measurements using the Morpheus 3D system at baseline, 6, 12, and 24 months post-treatment.

RESULTS

Quantitative analysis revealed a significant reduction in mid-face width from an average baseline of 149.27-145.00 mm at 24 months (p < 0.00001). Similarly, lower-face width decreased from 130.36 to 117.27 mm at 24 months (p < 0.00001). The GAIS scores demonstrated high levels of subject satisfaction, with 9 out of 11 patients reporting consistent satisfaction or improvement over 24 months. Minimal adverse events were reported, and no serious complications occurred.

DISCUSSION

The combination of HA fillers and PDO threads was effective in achieving and maintaining long-term improvements in facial volume and contour. The Morpheus 3D system provided objective volumetric data, which supported the subjective improvements observed by patients and investigators. The study results highlight the benefits of ongoing neocollagenesis and tissue remodeling beyond the dissolution period of the materials.

CONCLUSION

The combination of HA filler injections and PDO thread lifting offers a promising and minimally invasive option for long-term mid-face rejuvenation with high patient satisfaction and a favorable safety profile. Further studies are warranted to confirm these findings across diverse populations and compare this approach with other aesthetic treatments.

Poly-d,l-Lactic Acid Via Transdermal Microjet Drug Delivery for Treating Rosacea in Asian Patients

BACKGROUND

Rosacea, a chronic inflammatory skin condition, is marked by enduring redness, visible blood vessels, and inflammatory eruptions in facial areas. Managing rosacea remains a persistent challenge for dermatologists, especially in cases unresponsive to conventional treatments. Injectable poly-d,l-lactic acid (PDLLA) has shown promise in treating erythema and telangiectasia associated with rosacea in addition to age-related concerns. Employing Mirajet, a laser-induced microjet system, for administering PDLLA is a novel and promising treatment for rosacea.

AIMS

We aimed to evaluate the efficacy and safety of injectable PDLLA delivered via a needle-free microjet system for managing rosacea.

METHODS

Four Korean women with persistent and refractory rosacea received five monthly sessions of PDLLA needle-free injections. Clinical assessments were conducted using the Clinician's Erythema Assessment and Patient's Self-Assessment (PSA) at baseline, 4 weeks post-treatment, and 22 weeks post-final treatment. Adverse events were monitored throughout the study period.

RESULTS

At 4 weeks post-treatment, both Clinician's Erythema Assessment and PSA scores indicated significant improvements in erythema that were sustained up to the 22-week follow-up. Patients reported high satisfaction with resolution of redness and improved skin texture. Mild swelling, redness, and petechiae were observed post-treatment but resolved spontaneously. No product-related adverse events were noted during the study period.

CONCLUSION

Injectable PDLLA delivered via laser-induced microjet injection demonstrated promising efficacy in improving rosacea symptoms and skin quality for up to 22 weeks without significant adverse effects. Larger randomized controlled trials are needed to confirm these findings and evaluate long-term safety and sustainability of outcomes.

Variation of skin hydration profile with biophysical factors and lifestyle revealed by in vivo terahertz sensing

The skin, being the body's largest organ, plays a pivotal role in protecting the body against dangerous external factors. The maintenance of adequate hydration levels is essential for the skin to fulfill this protective function. However, skin hydration depends upon different biophysical factors and lifestyles, such as ethnicity, sex, age, water consumption, and many more. Consequently, methods to assess skin hydration in a precise and non-invasive manner are in high demand. In this paper, using a portable and handheld terahertz (THz) probe, we systematically examine the correlation between diverse biophysical factors and skin hydration profile in a population exceeding 300 participants. Through comparative analysis of THz light reflected from the skin against a dielectric model, we successfully extracted the thickness and hydration percentage of the outermost layer of the epidermis, the stratum corneum (SC). Our findings indicate that SC hydration and thickness are associated with variables such as daily water consumption, age, drinking coffee, and exercise. Additionally, our measurements reveal distinctions in the skin's hydration properties concerning susceptibility to UV-induced effects by bringing in the Fitzpatrick skin types. This THz-based technique holds the potential for facile integration into clinical settings for the evaluation and diagnosis of various skin-related conditions.

Association of Cellulitis With Obesity: Systematic Review and Meta-Analysis

BACKGROUND

Cellulitis is a bacterial skin infection that tends to recur. Previous studies have identified several risk factors that may contribute to its pathogenesis. Obesity is an increasingly prevalent worldwide disease that has been associated with skin and soft tissue infections.

OBJECTIVE

The aim of our systematic review and meta-analysis was to investigate the association of cellulitis with obesity.

METHODS

The Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science databases were searched for the relevant studies from the inception of each respective database to March 13, 2021. Case-control, cross-sectional, or cohort studies that examined the odds or risk of increased BMI in patients with cellulitis were included. This study was carried out in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The Newcastle-Ottawa scale (NOS) was used to evaluate the risk of bias in included studies.

RESULTS

In total, 9 case-control studies were included in our quantitative meta-analysis with a total of 68,148 study participants. A significant association was found between cellulitis and obesity (pooled odds ratio [OR] 2.67, 95% CI 1.91-3.71). No significant association was observed between cellulitis and being overweight (pooled OR 1.69, 95% CI 0.99-2.88). Patients with cellulitis were also found to have 1.63-fold increased odds of being male (pooled OR 1.63, 95% CI 1.12-2.38).

CONCLUSIONS

Our findings suggest that cellulitis is significantly associated with obesity. Maintaining a healthy BMI may be indicated for patients presenting with cellulitis.

Poly‐d,l‐lactic acid‐enhanced atrophic scar treatment via transdermal microjet drug delivery in Asians

BACKGROUND

Acne vulgaris often results in permanent scars, with atrophic scars being the most common type and posing a significant therapeutic challenge due to their prevalence and impact on patients' quality of life. Various treatment options exist, including the use of poly-d,l-lactic acid delivered via different methods.

OBJECTIVE

This study aimed to assess the efficacy and safety of poly-d,l-lactic acid delivered via laser-assisted needle-free microjet injection for treating atrophic scars.

METHODS

Five Korean participants with atrophic facial scars were recruited. Poly-d,l-lactic acid solution was administered via the Mirajet system in five sessions, with clinical assessments conducted at baseline, before each session, and at 12-week and 22-week follow-ups. Outcome measures included the Global Aesthetic Improvement Scale and patient satisfaction scores.

RESULTS

Positive results were observed at the 12-week and 22-week follow-ups, with high patient satisfaction and improvements in atrophic scars and skin texture. Mild discomfort and transient side effects were reported, with no adverse events observed during the follow-up period.

CONCLUSION

Poly-d,l-lactic acid delivered by a laser-assisted needle-free microjet injector was judged to be effective for improving atrophic the facial area. Further research, particularly through randomized controlled trials, is needed to validate these findings and assess the longer-term safety and sustainability of outcomes.

Polymeric Microneedles for Health Care Monitoring: An Emerging Trend

Bioanalyte collection by blood draw is a painful process, prone to needle phobia and injuries. Microneedles can be engineered to penetrate the epidermal skin barrier and collect analytes from the interstitial fluid, arising as a safe, painless, and effective alternative to hypodermic needles. Although there are plenty of reviews on the various types of microneedles and their use as drug delivery systems, there is a lack of systematization on the application of polymeric microneedles for diagnosis. In this review, we focus on the current state of the art of this field, while providing information on safety, preclinical and clinical trials, and market distribution, to outline what we believe will be the future of health monitoring.

Dermatology in black skin

The vast majority of publications in dermatology refer to lightly pigmented skin, with few addressing the peculiarities of black skin. In addition there is no consensus on what it means to be black in different regions of the world. The lack of knowledge on the subject makes it difficult to recognize and manage dermatoses in this type of skin. This article aims to review the literature on intrinsic characteristics, as well as epidemiological and clinical aspects of the cutaneous manifestations of different dermatoses in black skin. It was found that there are sometimes striking differences, in the structural, biological, and functional aspects when comparing lightly pigmented and black skin. There are also physiological changes that need to be recognized to avoid unnecessary interventions. Some dermatoses have a higher incidence in black skin, such as acne, eczema, dyschromia and dermatophytosis. On the other hand, several dermatoses are more specific to black skin, such as pseudofolliculitis barbae, keloid, dermatosis papulosa nigra, ulcers caused by sickle-cell anemia, dactylolysis spontanea, confluent and reticulated papillomatosis of Gougerot and Carteaud, and some diseases of the hair and scalp (including fragile and brittle hair, traction alopecia, folliculitis keloidalis nuchae, folliculitis dissecans and central centrifugal cicatricial alopecia). A spectrum of peculiar aspects of specific dermatoses, including sarcoidosis, lichen planus (with emphasis on the pigmentosus variant), psoriasis, lupus erythematosus, vitiligo, syphilis, pityriasis versicolor, and neoplasms are highlighted. In the latter, characteristics of basal cell carcinoma, squamous cell carcinoma, and melanoma are compared, in addition to highlighting unusual aspects of primary cutaneous T-cell lymphoma, endemic Kaposi sarcoma, and dermatofibrosarcoma protuberans.

Whose Signals Are Being Amplified? Toward a More Equitable Clinical Psychophysiology

Research using psychophysiological methods holds great promise for refining clinical assessment, identifying risk factors, and informing treatment. Unfortunately, unique methodological features of existing approaches limit inclusive research participation and, consequently, generalizability. This brief overview and commentary provides a snapshot of the current state of representation in clinical psychophysiology, with a focus on the forms and consequences of ongoing exclusion of Black participants. We illustrate issues of inequity and exclusion that are unique to clinical psychophysiology, considering intersections among social constructions of Blackness and biased design of current technology used to measure electroencephalography, skin conductance, and other signals. We then highlight work by groups dedicated to quantifying and addressing these limitations. We discuss the need for reflection and input from a wider variety of stakeholders to develop and refine new technologies, given the risk of further widening disparities. Finally, we provide broad recommendations for clinical psychophysiology research.

Optimal Changes Seen in Patients After Treatment With Poly- l -Lactic Acid: A Retrospective Descriptive Study

BACKGROUND

Poly- l -lactic acid (PLLA) is a biostimulator that enhances collagen production and leads to volume restoration. It became popular because of its improvement of facial wrinkles and long-lasting effect, although the specific visible changes it causes in the facial area are not fully described.

OBJECTIVE

To identify and characterize the visible changes resulting from injecting PLLA into the facial area.

METHODS

A list of 678 patients who underwent 2 to 3 treatments with PLLA injections in this center between 2021 and 2022 were retrieved. After 2 rounds of evaluations, 31 independent international evaluators described the 3 main changes they observed in the before-and-after images (taken approximately 7 months after the last injection session) of the 12 patients with the most significant improvement.

RESULTS

A total of 1,015 descriptions were received. They were divided into categories based upon similarity. The main detected changes were better contouring and enhancement of the lateral face, a lifting effect and secondary impact on the nasolabial fold, and improvement of skin texture and skin firmness.

CONCLUSION

Poly- l -lactic acid injections were judged to be effective for contouring, lifting, and improving skin texture in the facial area. Further research is needed to validate these results and create an assessment scale for PLLA injections.

Diversity of Asian skin: A review on skin biophysical properties

Asian is home to dozens of different ethnic groups that are characterised by fascinating social and cultural variations. Unfortunately, existing literature on the skin properties of Asians tends to group this diverse population solely based on skin colour, perpetuating the misconception and stereotype that all Asian skin is the same. While Asia is one of the largest continents in the world, the difference in the geographical location and climate have long shaped the population into various ethnic groups with significant differences in the collective and diverse customs, traditions, cultures and living habits. The diverse ethnic groups in this region hint us that their skin biophysical characteristics can be very different from each other. This review features the profiling of the distinctive skin biophysical properties of Asians. We learn more about the different ethnic groups in Asia and acknowledge the unique skin biophysical properties even from the same country.

Current Perspectives on Pressure Injuries in Persons with Dark Skin Tones from the National Pressure Injury Advisory Panel

BACKGROUND

Pressure injury (PI) development is multifactorial. In patients with dark skin tones, identifying impending PIs by visual skin assessment can be especially challenging. The need for improved skin assessment techniques, especially for persons with dark skin tones, continues to increase. Similarly, greater awareness of the need for inclusivity with regard to representation of diverse skin colors/tones in education materials is apparent.

OBJECTIVE

To provide current perspectives from the literature surrounding skin assessment and PI development in patients with dark skin tones.

METHODS

The following elements will be discussed through the lens of skin tone: (1) historical perspectives of PI staging from the National Pressure Injury Advisory Panel, (2) epidemiology of PI, (3) anatomy and physiology of the skin, (3) skin tone assessment and measurement, (4) augmented visual assessment modalities, (5) PI prevention, (6) PI healing, (7) social determinants of health, and (8) gaps in clinician education.

CONCLUSIONS

This article highlights the gap in our clinical knowledge regarding PIs in patients with dark skin tones. Racial disparities with regard to PI development and healing are especially clear among patients with dark skin tones. Skin tone color assessment must be standardized and quantifiable in clinical education, practice, and research. This work is urgently needed, and support from private and governmental agencies is essential.

Population pharmacokinetic analysis of transdermal granisetron in healthy Chinese and Caucasian volunteers

Granisetron patches are a prolonged delivery transdermal system that is used to prevent Chemotherapy-induced nausea and vomiting (CINV). To date, no pharmacokinetics comparison between Chinese and Caucasian populations has been conducted for granisetron patches. This study focused on the ethnic differences in pharmacokinetics (PK) of granisetron transdermal delivery system (GTDS) between Chinese and Caucasians and the influence of demographic covariates on pharmacokinetics (age, weight, height, body mass index, sex). To achieve this, blood concentration data were collected from 112 Caucasian healthy subjects participating in four clinical trials and 24 Chinese healthy subjects from one clinical trial, after a single application of the granisetron transdermal delivery system. A nonlinear mixed-effects model method of Phoenix NLME software was used to establish a population pharmacokinetic (Pop PK) model for Caucasian subjects. Bootstrap and visual predictive check (VPC) were used to validate the model. Based on the analysis a one-compartment model with first-order absorption and a first-order elimination well described the PK characteristics of GTDS. The apparent systemic clearance was determined to be 31316.3 mL/h and the central compartment volume of distribution was 6299.03 L. None of the five covariates (age, weight, height, body mass index, and sex) included in the Pop PK were significant covariates affecting PK. The final Pop PK model was used to simulate the Caucasian blood concentration by applying the dosing regimen used for the Chinese population. Comparison of the simulated Caucasian PK data with observed clinical PK data from Chinese healthy subjects revealed no significant differences in the main parameters, AUC_last and C_avg, between the two groups. These findings suggested that no dose adjustment was required when applied to the Chinese population. In conclusion, this Pop PK study comparing the transdermal patch in Chinese and Caucasian healthy subjects provided valuable insights for optimizing dosage across ethnicities.

Demographic and clinical characteristics of age-related distance esotropia

BACKGROUND

Age-related distance esotropia (ARDE), is an acquired, small, comitant esodeviation that is greater at distance than at near. It occurs in older adult patients without a history of neurological event or prior strabismus. It has been observed more frequently in White adults than in other racial groups. The purpose of this study was to assess the demographic and clinical characteristics of patients with ARDE presenting at a tertiary neuro-ophthalmology clinic.

METHODS

In this retrospective study, ICD-9/10 (ICD-9 378.85 and ICD-10 H51.8) codes were used to identify all patients with ARDE from 2005 to 2020 seen in a single tertiary neuro-ophthalmology clinic. ARDE was defined as esotropia greater at distance than near with associated clinical signs of adnexal tissue laxity. Patients with history or findings compatible with other etiologies of strabismus, such as thyroid eye disease, neuromuscular disorders, sensory deviations, sudden onset of diplopia, and high myopia, as well as those with prior strabismus surgery, were excluded.

RESULTS

A total of 89 patients (59 females [66%]) met inclusion criteria. Mean patient age was 76.6 years. All patients were White except for a single patient of African descent. Mean follow-up time was 25.2 months. Mean esodeviation at distance on presentation was 6.6Δ. Of the 87 patients electing nonsurgical treatment, 80 achieved remission of diplopia symptoms with prism therapy alone. Of the 89 patients, 59 had no neuroimaging.

CONCLUSIONS

ARDE in our neuro-ophthalmology clinic population was diagnosed almost exclusively in older White adults. Prism therapy was effective for a majority of our patients.

Influence of the emulsifier on nanostructure and clinical application of liquid crystalline emulsions

Liquid crystals are appealing in pharmaceutical and cosmetic fields due to their unique structures that combine the properties of both liquid and solid states. Forming an emulsion into liquid crystals can be affected by a number of factors, including the emulsion composition and temperature. Changing the types and concentrations of surfactants could be another factor that affects liquid crystals. Currently, most liquid crystal research focuses on the nanostructure of liquid crystal systems without evaluating the efficacy of liquid crystals clinically. In this study, liquid crystalline emulsions made from camellia seed oil with four different surfactants (Olivem 1000, Polyaquol-2W, Nikkomulese LC, and Lecinol S-10 with Tween 80) were created. The liquid crystal emulsions were formulated in the form of oil-in-water (o/w) emulsions with Camellia oleifera seed oil serving as the main ingredient in the oil phase (10% w/w). All formulations exhibited liquid crystal characteristics with lamellar structures as determined by the polarized light microscopy and small-angle X-ray scattering with supporting data of the nanostructure from wide-angle X-ray scattering and differential scanning calorimetry (DSC). They all showed good stability under normal (room temperature) and accelerated conditions (4 °C and 40 °C) in long-term storage (6 months). Using the reconstructed human epidermis as a skin model, all formulations did not cause skin irritation. In the clinical trial, all formulations were able to reduce transepidermal water loss (TEWL) and increase skin hydration immediately after application. This lasted at least 10 h. All formulations showed distinct Maltese crosses under the polarized light microscope with a positive result for liquid crystals in wide angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS) methods. Moreover, among all formulations tested, Formulation D, which contained Lecinol S-10 and Tween 80 as emulsifiers, showed the most robust interaction between the surfactant and water molecules in the lamellar structure under DSC. The formulation was stable in long-term normal and accelerated conditions. Above all, Formulation D, which was formulated with Lecinol S-10 with Tween 80, had the best clinical result, was nonirritating to the skin, and can be used as a cream base in the pharmaceutical and cosmeceutical sectors.

The Imprint of Exposome on the Development of Atopic Dermatitis across the Lifespan: A Narrative Review

Atopic dermatitis (AD) is a chronic inflammatory skin condition that affects more than 200 million people worldwide, including up to 20% of children and 10% of the adult population. Although AD appears frequently in childhood and often continues into adulthood, about 1 in 4 adults develop the adult-onset disease. The prenatal period, early childhood, and adolescence are considered critical timepoints for the development of AD when the exposome results in long-lasting effects on the immune system. The exposome can be defined as the measure of all the exposures of an individual during their lifetime and how these exposures relate to well-being. While genetic factors could partially explain AD onset, multiple external environmental exposures (external exposome) in early life are implicated and are equally important for understanding AD manifestation. In this review, we describe the conceptual framework of the exposome and its relevance to AD from conception and across the lifespan. Through a spatiotemporal lens that focuses on the multi-level phenotyping of the environment, we highlight a framework that embraces the dynamic complex nature of exposome and recognizes the influence of additive and interactive environmental exposures. Moreover, we highlight the need to understand the developmental origins of AD from an age-related perspective when studying the effects of the exposome on AD, shifting the research paradigm away from the per se categorized exposome factors and beyond clinical contexts to explore the trajectory of age-related exposome risks and hence future preventive interventions.

Comparison of real-world treatment outcomes of systemic immunomodulating therapy in atopic dermatitis patients with dark and light skin types

Background

Few data exist on differences in treatment effectiveness and safety in atopic dermatitis patients of different skin types.

Objective

To investigate treatment outcomes of dupilumab, methotrexate, and ciclosporin, and morphological phenotypes in atopic dermatitis patients, stratified by Fitzpatrick skin type.

Methods

In an observational prospective cohort study, pooling data from the Dutch TREAT (TREatment of ATopic eczema) NL (treatregister.nl) and UK-Irish A-STAR (Atopic eczema Systemic TherApy Register; astar-register.org) registries, data on morphological phenotypes and treatment outcomes were investigated.

Results

A total of 235 patients were included (light skin types [LST]: Fitzpatrick skin type 1-3, n = 156 [Ethnicity, White: 94.2%]; dark skin types [DST]: skin type 4-6, n = 68 [Black African/Afro-Caribbean: 25%, South-Asian: 26.5%, and Hispanics: 0%]). DST were younger (19.5 vs 29.0 years; P < .001), more often had follicular eczema (22.1% vs 2.6%; P < .001), higher baseline Eczema Area and Severity Index (EASI) scores (20.1 vs 14.9; P = .009), less allergic contact dermatitis (30.9% vs 47.4%; P = .03), and less previous phototherapy use (39.7% vs 59.0%; P = .008). When comparing DST and LST corrected for covariates including baseline EASI, DST showed greater mean EASI reduction between baseline and 6 months with only dupilumab (16.7 vs 9.7; adjusted P = .032). No differences were found for adverse events for any treatments (P > .05).

Limitations

Unblinded, non-randomized.

Conclusion

Atopic dermatitis differs in several characteristics between LST and DST. Skin type may influence treatment effectiveness of dupilumab.

Viscoelastic Properties of Human Facial Skin and Comparisons with Facial Prosthetic Elastomers

Prosthesis discomfort and a lack of skin-like quality is a source of patient dissatisfaction with facial prostheses. To engineer skin-like replacements, knowledge of the differences between facial skin properties and those for prosthetic materials is essential. This project measured six viscoelastic properties (percent laxity, stiffness, elastic deformation, creep, absorbed energy, and percent elasticity) at six facial locations with a suction device in a human adult population equally stratified for age, sex, and race. The same properties were measured for eight facial prosthetic elastomers currently available for clinical usage. The results showed that the prosthetic materials were 1.8 to 6.4 times higher in stiffness, 2 to 4 times lower in absorbed energy, and 2.75 to 9 times lower in viscous creep than facial skin (p < 0.001). Clustering analyses determined that facial skin properties fell into three groups-those associated with body of ear, cheek, and remaining locations. This provides baseline information for designing future replacements for missing facial tissues.

Quality of fetal heart rate monitoring with transabdominal fetal ECG during maternal movement in labor: A prospective study

INTRODUCTION

Transabdominal electrocardiographic (TAfECG) acquisition of fetal heart rate (FHR) signals has recently been introduced into leading commercial cardiotocographic (CTG) monitors. Continuous wireless transmission of signals has raised the possibility of the technology being used during maternal mobilization in labor. This study aims to evaluate signal quality and accuracy of TAfECG acquisition of FHR signals during static and active maternal positions in labor when compared with Doppler signals and with the gold-standard method of fetal scalp electrode (FSE).

MATERIAL AND METHODS

A total of 76 women with singleton term pregnancies in the active first stage of labor had simultaneously acquired FHR with TAfECG, Doppler, and FSE. Participants were asked to complete a supervised mobilization scheme, comprising five sequential 10-min periods of lying down, standing, sitting, walking, and rocking on the birthing ball. The three FHR signals were compared, defining signal loss as the percentage of signals under 20 bpm or exceeding 250 bpm and accuracy as the difference with FSE values. Computer analysis was used to quantify variability, accelerations, and decelerations. Static labor positions (lying down, standing, and sitting) were compared with active labor positions (walking and rocking on the birthing ball).

RESULTS

Average signal loss was 5.3% with TAfECG (3.2% in static and 7.4% in active positions) and 15.5% with Doppler (8.3% in static and 30.7% in active positions). Average accuracy was 3.5 bpm with TAfECG (1.9 bpm in static and 5.04 bpm in active positions) and 13.9 bpm with Doppler (3.2 bpm in static and 24.7 bpm in active positions). Average variability was similar with TAfECG and FSE in static positions but significantly higher with TAfECG in active positions (23.6 vs. 13.5 bpm, p < 0.001).

CONCLUSIONS

In static labor positions, TAfECG provides a low signal loss, similar to that obtained with FSE, and a good signal accuracy, so the technique can be considered reliable when the mother is lying down, standing, or sitting. During maternal movement, TAfECG causes an artificial increase in FHR variability, which can cause false reassurance regarding fetal oxygenation. Doppler signals are unreliable during maternal movements.

A lack of race and ethnicity data in the treatment of hereditary hemorrhagic telangiectasia: a systematic review of intravenous bevacizumab efficacy

BACKGROUND

For extreme hereditary hemorrhagic telangiectasia (HHT) disease, treatments such as intravenous bevacizumab are often utilized. However, whether its efficacy is similar across diverse races and ethnicities is unclear.

METHODS

In this systematic review, we performed a search for English-language articles identified through PubMed, Embase, and Scopus databases whose research occurred in the United States (US). Search terms related to HHT, epistaxis, and intravenous bevacizumab. We searched specifically for the intervention of intravenous bevacizumab because the term serves as a suitable surrogate to convey a patient who has both a diagnosis of HHT and established care. We focused on number of patients recruited in intravenous bevacizumab trials who were identified by race or ethnicity.

RESULTS

Our search identified 79 studies, of which four were conducted in the US. These four were selected for our systematic review. In these studies, 58 total patients were evaluated (ranging from 5 to 34 participants), whereby, information on age and gender were included. However, none of the US-based studies shared race or ethnicity data.

CONCLUSION

Inability to find studies regarding intravenous bevacizumab use in patients with HHT in which race and ethnicity are reported limits our ability to understand the therapy's efficacy in specific populations. Without emphasis on race and ethnicity in such trials, showing the potential of HHT-related diversity in individuals with this disease may reaffirm implicit bias around HHT diagnosis and treatment. Future work on HHT should emphasize sociodemographic data collection and reporting in an effort to understand this disease in diverse populations.

Recognizing Drug Hypersensitivity in Pigmented Skin

The imagery of pigmented skin is underrepresented in teaching materials such as textbooks, journals, and online references, and this has resulted in poorer diagnostic and management outcomes of skin pathology, including delayed cutaneous drug hypersensitivity reactions. In this review, we use clinical images to highlight factors that impact clinical presentations and sequelae of drug hypersensitivity reactions in pigmented skin compared with nonpigmented skin. We describe clinical features in some anatomic sites that aid diagnosis or are associated with more severe sequelae. Finally, we discuss strategies that may aid the diagnosis and management of these reactions in pigmented skin.

Development of a numerical multi-layer model of skin subjected to pulsed laser irradiation to optimise thermal stimulation in photorejuvenation procedure

BACKGROUND AND OBJECTIVE

This paper presents the development of a 3D physics-based numerical model of skin capable of representing the laser-skin photo-thermal interactions occurring in skin photorejuvenation treatment procedures. The aim of this model was to provide a rational and quantitative basis to control and predict temperature distribution within the layered structure of skin. Ultimately, this mathematical and numerical modelling platform will guide the design of an automatic robotic controller to precisely regulate skin temperature at desired depths and for specific durations.

METHODS

The Pennes bioheat equation was used to account for heat transfer in a 3D multi-layer model of skin. The effects of blood perfusion, skin pigmentation and various convection conditions are also incorporated in the proposed model. The photo-thermal effect due to pulsed laser light on skin is computed using light diffusion theory. The physics-based constitutive model was numerically implemented using a combination of finite volume and finite difference techniques. Direct sensitivity routines were also implemented to assess the influence of constitutive parameters on temperature. A stability analysis of the numerical model was conducted.

RESULTS

Finally, the numerical model was exploited to assess its ability to predict temperature distribution and thermal damage via a multi-parametric study which accounted for a wide array of biophysical parameters such as light coefficients of absorption for individual skin layers and melanin levels (correlated with ethnicity). It was shown how critical is the link between melanin content, laser light characteristics and potential thermal damage to skin.

CONCLUSIONS

The developed photo-thermal model of skin-laser interactions paves the way for the design of an automated simulation-driven photorejuvenation robot, thus alleviating the need for inconsistent and error-prone human operators.

An update on cosmetic procedures in people of color. Part 1: Scientific background, assessment, preprocedure preparation

Increased life expectancy, focus on appearance, and readily available and accessible cosmetic procedures have served to drive an increase in the number of nonsurgical cosmetic procedures performed in the last 20 years. Demographic shifts in the United States, with increases in diverse populations that seek nonsurgical cosmetic procedures, have resulted in the need for a better understanding of cultural preferences as well as structural and biological differences in the skin of people of color (POC). Although many advances in the form of cosmeceuticals, cosmetics, and photoprotection have been made to address the aesthetic needs of and minimize complications in POC, nonsurgical cosmetic procedures are required to address common aesthetic concerns. Gaps remain in the education of dermatologists regarding the appropriate selection and execution of nonsurgical cosmetic procedures in POC. This educational initiative will facilitate a favorable outcome and optimal cosmetic results for POC.

Forehead, Temple and Wrist Temperature Assessment of Ethnic Groups using Infrared Technology

Non-contact infrared sensors are widely used as a diagnostic tool for elevated body temperature during initial screening for coronaviruses. The aim of this study was to investigate the thermal differences at three anatomical points: temple, forehead, and wrist, in the initial screening for temperature indicative of febrile and non-febrile states in skin pigmentation variations in Black, Half-Black and Caucasian skins, correlated with height and weight variables. Temperatures were obtained by means of an infrared thermometer in 289 volunteers with mean age of 18.30 ± 0.76, in a controlled environment according to Singapore Standard, SS582 part 1 and 2, normative standard IEC 80601-2-59, with standard technical protocols established by the International Organization for Standardization, ISO / TR 13154. The data were processed in MATLAB® R2021a, and data normality verified by Kolmogorov-Smirnov test, non-parametric data paired between temple / forehead / wrist were compared using the Wilcoxon signed-rank test. The results show different median temperatures in these anatomical regions, 37.2°C at the temple, 36.8°C at the forehead and 36.4°C at the wrist. As the temple region presents a temperature higher than the other investigated regions and, therefore, close to the core temperature, it should be considered for the initial screening of SARS-CoV-2 when using non-contact infrared thermometers. Furthermore, no significant changes were found due to variation in skin tone, height, or weight.

Cranioplasty Outcomes From 500 Consecutive Neuroplastic Surgery Patients

BACKGROUND

Cranioplasty is critical to cerebral protection and restoring intracranial physiology, yet this procedure is fraught with a high risk of complications. The field of neuroplastic surgery was created to improve skull and scalp reconstruction outcomes in adult neurosurgical patients, with the hypothesis that a multidisciplinary team approach could help decrease complications.

OBJECTIVE

To determine outcomes from a cohort of cranioplasty surgeries performed by a neuroplastic surgery team using a consistent surgical technique and approach.

METHODS

The authors reviewed 500 consecutive adult neuroplastic surgery cranioplasties that were performed between January 2012 and September 2020. Data were abstracted from a prospectively maintained database. Univariate analysis was performed to determine association between demographic, medical, and surgical factors and odds of revision surgery.

RESULTS

Patients were followed for an average of 24 months. Overall, there was a reoperation rate of 15.2% (n = 76), with the most frequent complications being infection (7.8%, n = 39), epidural hematoma (2.2%, n = 11), and wound dehiscence (1.8%, n = 9). New onset seizures occurred in 6 (1.2%) patients. Several variables were associated with increased odds of revision surgery, including lower body mass ratio, 2 or more cranial surgeries, presence of hydrocephalus shunts, scalp tissue defects, large-sized skull defect, and autologous bone flaps. Importantly, implants with embedded neurotechnology were not associated with increased odds of reoperation.

CONCLUSIONS

These results allow for comparison of multiple factors that impact risk of complications after cranioplasty and lay the foundation for development of a cranioplasty risk stratification scheme. Further research in neuroplastic surgery is warranted to examine how designated centers concentrating on adult neuro-cranial reconstruction and multidisciplinary collaboration may lead to improved cranioplasty outcomes and decreased risks of complications in neurosurgical patients.

Did human evolution in skin of color enhance the TEWL barrier?

United States will soon be a nation of color; however, much of our knowledge of normal skin disease, and treatment thereof is based on white skin. We and others have attempted to elucidate any potential differences and advantages/disadvantages in skin function that have emerged during homo sapiens evolution post major migration from Eastern Africa. We investigated differences in one stratum corneum function by examining transepidermal water loss (TEWL) measurements in skin of color compared to Caucasian skin. TEWL, a measure of insensible water loss through stratum corneum, plays a major role in human survival. A comprehensive literature search was conducted to procure relevant papers that measured baseline TEWL in skin of color and Caucasian skin. The data show wide contradiction in results for all skin of color groups and white skin and, therefore, no conclusion can be made based on this question. We suggest this variation may be due to experimental confounding variables that impact TEWL quantification, such as anatomic site and sample size subject to further analysis and focus.

Transdermal Drug Delivery in the Pig Skin

Transdermal delivery can be accomplished through various mechanisms including formulation optimization, epidermal stratum corneum barrier disruption, or directly by removing the stratum corneum layer. Microneedling, electroporation, a combination of both and also the intradermal injection known as mesotherapy have proved efficacy in epidermal-barrier disruption. Here we analyzed the effects of these methods of epidermal-barrier disruption in the structure of the skin and the absorption of four compounds with different characteristics and properties (ketoprofen, biotin, caffein, and procaine). Swine skin (Pietrain x Durox) was used as a human analogue, both having similar structure and pharmacological release. They were biopsied at different intervals, up to 2 weeks after application. High-pressure liquid chromatography and brightfield microscopy were performed, conducting a biometric analysis and measuring histological structure and vascular status. The performed experiments led to different results in the function of the studied molecules: ketoprofen and biotin had the best concentrations with intradermal injections, while delivery methods for obtaining procaine and caffein maximum concentrations changed on the basis of the lapsed time. The studied techniques did not produce significant histological alterations after their application, except for an observed increase in Langerhans cells and melanocytes after applying electroporation, and an epidermal thinning after using microneedles, with variable results regarding dermal thickness. Although all the studied barrier disruptors can accomplish transdermal delivery, the best disruptor is dependent on the particular molecule.

An objective skin-type classification based on non-invasive biophysical parameters

BACKGROUND

Despite the invention of various non-invasive bioengineering tools, skin-type analysis has largely been based on subjective assessments. However, advancements in the functional cosmetic industry and artificial intelligence-assisted dermatology are creating a greater demand for an objective skin-type classification system.

OBJECTIVES

To propose an objective skin-type classification system solely based on non-invasive, bioengineering devices; provide reference values applicable to the Korean population; and compare our reference values with those of published studies.

METHODS

Biophysical parameter measurements were obtained from the 2018 International Skin Characteristics Data Bank Project conducted by the Foundation of Korea Cosmetic Industry Institute. The participants were 434 healthy South Korean adults. Each participant was assessed using eight bioengineering devices (Tewameter^® , pH-meter^® , Corneometer^® , Sebumeter^® , Cutometer^® , Spectrophotometer^® , PRIMOS^® lite, and Janus^® ). The measurements were divided into tertiles to determine reference points.

RESULTS

Our objective skin-type classification consists of five main categories (sensitivity, hydration, oiliness, elasticity, and skin tone) and five corresponding subcategories (erythema, roughness, pores, wrinkles, and pigmentation, respectively). Each skin type was assigned based on the reference point of the biophysical parameter, which was established as the tertile value associated with 'unfavourable' skin characteristics. Individuals were categorized as having sensitive skin when the TEWL scores were over 18.0 g/m² /h or the pH was over 5.45; dehydrated skin when the corneometric value measured below 47.17 A.U.; oily skin when the sebumetric value exceeded 70 μg/cm² ; and loose skin when the cutometric R² value was below 0.68 E/mm.

CONCLUSIONS

This study is the first to provide a comprehensive skin-type classification system based solely on non-invasive biophysical parameters. As measurement data accumulate, the reference points will progress to become more accurate, and they will be subdivided according to gender, age, and ethnic group. Therefore, our classification system serves as a basis for artificial intelligence-based skin-type analysis.

Review article: Emerging issues in pediatric skin of color, Part 2

Dermatology for pediatric skin of color is the application of dermatology to the genetically diverse and distinctive segment of the pediatric population that includes children of non-White racial and ethnic groups with increased pigmentation including individuals of Asian, Hispanic/LatinX, African, Native American, Pacific Island descent, indigenous people among others with overlap in particular individuals, and mixtures thereof. The discipline of pediatric skin of color can be challenging with difficulty in diagnosis of common conditions due to underlying pigmentation, variations in common hair styling practices, and differences in demographics of cutaneous disease. Whereas some conditions are more common in children of color, other conditions have nuances in clinical appearance and therapeutics with regard to skin color. This article, the second of the series, focuses on inflammatory skin disease nuances, melanocytic disorders, and hypopigmented mycosis fungoides.

Reframing racial and ethnic disparities in atopic dermatitis in Black and Latinx populations

Black people in the United States experience greater atopic dermatitis (AD) prevalence, severity, and persistence when compared with White people. Although very little published literature describes AD in the Latinx population, additional differences in severity, persistence, and age of onset exist in contrast to White people. Thus far, genetic polymorphisms associated with increased risk and/or severity of AD are less common among Black people, so should confer reduced, rather than the observed increased, AD risk among Black people. Little is known regarding genetic risk factors in Latinx people. In contrast, there is consistent evidence that socioeconomic, environmental, and health care factors influence AD prevalence, severity, and/or persistence, and these same risk factors are more common among racial and ethnic minority populations as a result of racism. Researchers too often pursue genetic explanations for racial and ethnic AD disparities when the evidence points to the importance of contextual, rather than genetic, causes of these disparities. Reframing the prevailing view that innate differences among racial and ethnic groups are responsible for these disparities by emphasizing the role of racism and its downstream effects on contextual factors will be a critical first step toward shrinking these disparities.

Study of the characteristics of facial skin tone status in 1092 young Chinese females according to the ITA°

BACKGROUND

The ITA° is the gold standard for skin tone classification. Different skin tones are often associated with different skin characteristics and issues. Different skin types are often associated with different skin characteristics and issues in China.

AIMS

To study the population's skin color distribution and accompanying skin problems according to the ITA° classification standard.

METHODS

A total of 1092 women aged 22-42 years were recruited in 7 cities in China. All biophysical parameter measurements (SM, CM, TWEL, pH, R2, GLOSS_DSCT, MEXA, ERYTH, ITA°; 9 indexes total) were quantified with noninvasive instruments. All volunteers provided consent before enrollment.

RESULT

The main skin color categories were light (II), very light (I), intermediate (III), and tan (IV). The results demonstrated that the characteristics of the facial skin based on the ITA° were significantly different among cities and age groups and were associated with different skin issues.

CONCLUSIONS

Lighter skin was associated with worse skin elasticity; intermediate skin was associated with worse skin hydration content and was most prone to being oily; and darker skin was associated with poor barrier function. Established principal component regression (PCR) indicated that pH, gloss GLOSS_DSC, MEXA, ERYTH, TEWL, and SM had significant effects on the ITA°.

Differences between perceived age and chronological age in women: A multi-ethnic and multi-centre study

Objective

Accuracy in assessing age from facial cues is important in social perception given reports of strong negative correlations between perceived age and assessments of health and attractiveness. In a multi‐ethnic and multi‐centre study, we previously documented similar patterns of female facial age assessments across ethnicities, influenced by gender and ethnicity of assessors.

Methods

Here we extend these findings by examining differences between estimated age from digital portraits and chronological age (Δ age) for 180 women from three age groups (20–34, 35–49, 50–66 years) and five ethnicities (36 images of each ethnicity, assessed for age on a continuous scale by 120 female and male raters of each ethnicity).

Results

Across ethnicities, Δ age was smallest in French assessors and largest in South African assessors. Numerically, French women were judged oldest and Chinese women youngest relative to chronological age. In younger women, Δ age was larger than in middle‐aged and older women. This effect was particularly evident when considering the interaction of women's age with assessor gender and ethnicity, independently and together, on Δ age.

Conclusion

Collectively, our findings suggest that accuracy in assessments of female age from digital portraits depends on the chronological age and ethnicity of the photographed women and the ethnicity and gender of the assessor. We discuss the findings concerning ethnic variation in skin pigmentation and visible signs of ageing and comment on implications for cosmetic science.

Chronic itch in African Americans: an unmet need

Chronic pruritus carries a significant burden of disease and is associated with a negative impact on quality of life. African Americans are disproportionately burdened by chronic pruritic disorders, including but not limited to atopic dermatitis, prurigo nodularis, inflammatory scalp dermatoses, pathologic scarring, and HIV-related dermatoses. Racial differences in skin structure and function may contribute to the pathogenesis of itch in African Americans. Itch perception and response to treatment in African Americans remain understudied and not well understood. As such, there is a large unmet need with regard to the knowledge and management of pruritus in African Americans. This review highlights notable differences in the epidemiology, pathophysiology, genetic predisposition, clinical presentation, and response to treatment for select pruritic skin conditions. By addressing itch as an unmet need in African Americans, we hope to improve patient outcomes and lessen disparities in dermatologic care.

Touch-Based Fingertip Blood-Free Reliable Glucose Monitoring: Personalized Data Processing for Predicting Blood Glucose Concentrations

Diabetes prevalence has been rising exponentially, increasing the need for reliable noninvasive approaches for glucose monitoring. Different biofluids have been explored recently for replacing current blood finger-stick glucose strips with noninvasive painless sensing devices. While sweat has received considerable attention, there are mixed reports on correlating the sweat results with blood glucose levels. Here, we demonstrate a new rapid and reliable approach that combines a simple touch-based fingertip sweat electrochemical sensor with a new algorithm that addresses for personal variations toward the accurate estimate of blood glucose concentrations. The new painless and simple glucose self-testing protocol leverages the fast sweat rate on the fingertip for rapid assays of natural perspiration, without any sweat stimulation, along with the personalized sweat-response-to-blood concentration translation. A reliable estimate of the blood glucose sensing concentrations can thus be realized through a simple one-time personal precalibration. Such system training leads to a substantially improved accuracy with a Pearson correlation coefficient higher than 0.95, along with an overall mean absolute relative difference of 7.79%, with 100% paired points residing in the A + B region of the Clarke error grid. The speed and simplicity of the touch-based blood-free fingertip sweat assay, and the elimination of periodic blood calibrations, should lead to frequent self-testing of glucose and enhanced patient compliance toward the improved management of diabetes.

Micropore Closure Rates following Microneedle Application at Various Anatomical Sites in Healthy Human Subjects

INTRODUCTION

The continuous availability of open micropores is crucial for a successful microneedle (MN) drug delivery strategy. However, micropore lifetime depends on intrinsic skin functional and anatomical characteristics, which vary significantly at different anatomical sites.

OBJECTIVE

This pilot study explored if differences exist in micropore closure timeframes at 3 anatomical sites - upper arm, volar forearm, and abdomen.

METHODS

Healthy subjects (n = 35) self-identifying as Asian (n = 9), Bi-/multiracial (n = 2), Black (n = 9), Latino (n = 6), and White (n = 9) completed the study. The upper arm, volar forearm, and abdomen were treated with MNs; skin impedance and transepidermal water loss (TEWL) were measured at baseline and post-MN to confirm micropore formation. Impedance was measured for 3 days to evaluate micropore lifetime. Measurements of L*, which quantifies the skin lightness/darkness, were made using a tristimulus colorimeter. Micropore lifetime was determined by comparing baseline and post-MN impedance measurements, and micropore closure half-life was predicted using mathematical modeling.

RESULTS

Post-MN increase in TEWL and decrease in impedance were significant (p < 0.05), confirming successful micropore formation at all anatomical sites. When data were analyzed according to subject self-identified racial/ethnic groups, the mean micropore closure time at the abdomen (63.09 ± 13.13 h) was longer than the upper arm (60.34 ± 14.69 h) and volar forearm (58.29 ± 16.76 h). The predicted micropore closure half-life at anatomical sites was the abdomen (25.86 ± 14.96 h) ≈ upper arm (23.69 ± 13.67 h) > volar forearm (20.2 ± 11.99 h). Differences were not statistically significant between groups. Objective categorization by L* showed that the darker skin may be associated with longer micropore closure time at the abdomen site.

CONCLUSIONS

Our results suggest that anatomical site of application may not be a source of significant variability in micropore closure time. These findings may help reduce the number of physiological parameters that need to be explicitly considered when developing drug products to support MN-assisted drug delivery strategies.

Facial Skin Biophysical Profile of Women in Malaysia: Significance of Facial Skincare Product Use

INTRODUCTION

At present, there is a lack of baseline data on the facial skin biophysical profile of women in Malaysia. The implications related to the daily habits and facial skincare product use on the skin biophysical condition are, thus, unknown. In this study, we aim to evaluate facial skin biophysical parameters of Malaysian women and examine the influence of demographic characteristics, daily habits, and facial skincare product use on these parameters.

METHODS

Four skin biophysical parameters - transepidermal water loss (TEWL), melanin content, elasticity, and collagen intensity - were assessed on the cheek of the subjects (20-60 years). Demographic background, daily habits, and skincare product use were gauged through a survey. Only 197 from the 213 subjects recruited initially were used for analysis after the data were screened for normality.

RESULTS

The biophysical parameters were similar in different races, except a higher melanin content in Indian female individuals. Elasticity and collagen intensity reduced with age, while melanin content increased in the older age-groups. But no difference was observed in TEWL at different ages. Evaluating the influence of daily habits, we observed that exercise significantly lowered TEWL and increased melanin content, which may be associated with UV radiation exposure. Facial skincare products are popular among the female subjects (>85% users). Products with moisturizing, sunscreening, and other skincare functions (astringent, antiaging, and anti-wrinkle) were preferred by subjects of all ages. These product functions significantly improve skin elasticity and reduce melanin content in the young adults. While aged women recognized the importance of having an additional skin-lightening function in their skincare routine. Although the influence of individual skincare function on skin biophysical parameters was mostly positive, the alteration of these parameters varied at different ages.

CONCLUSION

This is the first report of facial skin biophysical profile of Malaysian women. There is no difference among 3 major races saved for melanin content. This work demonstrated age-dependent influences on the biophysical parameters, except TEWL. The significance of skincare product use is well reflected in the improvement of these parameters at different age-groups based on individual skincare functions.

Micropore closure time is longer following microneedle application to skin of color

Microneedles (MNs) allow transdermal delivery of skin-impermeable drugs by creating transient epidermal micropores, and micropore lifetime directly affects drug diffusion timeframes. Healthy subjects (n = 111) completed the study, self-identifying as Asian (n = 32), Bi-/multi-racial (n = 10), Black (n = 22), White (n = 23), Latino (n = 23), and Native American/Hawaiian (n = 1). L* was measured with tristimulus colorimetry to objectively describe skin lightness/darkness. MNs were applied to the upper arm; impedance and transepidermal water loss (TEWL) were measured at baseline and post-MN to confirm micropore formation. Impedance was repeated for 4 days to determine micropore lifetime. Post-MN changes in TEWL and impedance were significant in all groups (p < 0.05), confirming micropore formation regardless of skin type. Micropore lifetime was significantly longer in Blacks (66.5 ± 19.5 h) versus Asians (44.1 ± 14.0 h), Bi-/multi-racial (48.0 ± 16.0 h), and Whites (50.2 ± 2.6 h). Latinos (61.1 ± 16.1 h) had significantly longer micropore closure time versus Asians (44.1 ± 14.0 h). When categorizing data according to L*, micropore lifetime was significantly longer in darker skin. We report for the first time that micropore lifetime differences are present in human subjects of different ethnic/racial backgrounds, with longer micropore lifetime in skin of color. These results also suggest that objectively measured skin color is a better predictor of micropore lifetime than self-identified race/ethnicity.

The mechanisms of action and use of botulinum neurotoxin type A in aesthetics: Key Clinical Postulates II

BACKGROUND

The literature on botulinum neurotoxin type A (BoNT-A) is extensive, often contradictory, and confounded by a competitive market of products and research attempting to distinguish brand individuality.

METHODS

A comprehensive review of literature on the principles of BoNT-A in aesthetics as well as clinical examples.

RESULTS

In 2017, the Eight Key Clinical Postulates were formulated as a guide for the aesthetic practitioner in understanding BoNT-A pharmacodynamics and to compare different toxins. These are now updated to include (a) All type A toxins act identically; (b) The mathematical relationship between toxin and receptor is the basis of efficacy, and clinical efficacy is influenced by molecular potency and patient attributes including muscle mass, gender, age, and ethnicity; (c) Efficacy, onset, and duration are functions of "molecular potency" defined as the number of active 150 kDa molecules available for binding; (d) "Molecular potency" is difficult to objectively quantify for commercially available toxins; (e) Up to a point, increased molecular potency decreases time to onset and increases duration of effect, and the "Molecular Potency Quotient" is a construct for comparing molecular potency commercial cost; (f) The area of effect of a toxin injection is dependent upon molecular potency, diffusion (passive), and spread (active); (g) Differing reconstitution volumes; and (h) Increased number of injection sites can affect spread, onset, and duration of effect.

CONCLUSIONS

The principles of BoNT-A use in aesthetics are complex yet understandable as outlined in the framework of the updated Eight Key Clinical Postulates and serves as a useful tool for providing the most effective treatment and interpreting research on present and future toxin formulations.

The role of dermatology in African patients referred for health treatment in a European centre

BACKGROUND

Owing to the migratory movement between African and European countries, we have been seeing an increasing number of dermatoses in patients with darker skin phenotypes in our clinical practice.

AIM

To evaluate the support provided by outpatient dermatology consultations to such patients and to assess the most frequent dermatoses seen in this population.

METHODS

A retrospective 5-year study was conducted in a Portuguese hospital, which is a referral centre to several medical specialities for patients evacuated from Portuguese-speaking African countries, under a specific agreement of international cooperation in health.

RESULTS

In total, 116 patients, with a mean age of 38 years, were evaluated. In total, 47 dermatoses were identified, with the 6 most common being fungal infections (12.1%), eczema (9.5%), dyschromias (8.6%), xerosis (6.9%), acne (6%) and hair disorders (6%).

CONCLUSIONS

This increased knowledge about the most frequent dermatoses in this population, along with their manifestations and the factors that influence them should allow better diagnosis and therapy.