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The Greying with age phenotype in horses involves loss of hair pigmentation whereas skin pigmentation is not reduced, and a predisposition to melanoma. The causal mutation was initially reported as a duplication of a 4.6 kb intronic sequence in Syntaxin 17. The speed of greying varies considerably among Grey horses. Here we demonstrate the presence of two different Grey alleles, G2 carrying two tandem copies of the duplicated sequence and G3 carrying three. The latter is by far the most common allele, probably due to strong selection for the striking white phenotype. Our results reveal a remarkable dosage effect where the G3 allele is associated with fast greying and high incidence of melanoma whereas G2 is associated with slow greying and low incidence of melanoma. The copy number expansion transforms a weak enhancer to a strong melanocyte-specific enhancer that underlies hair greying (G2 and G3) and a drastically elevated risk of melanoma (G3 only). Our direct pedigree-based observation of the origin of a G2 allele from a G3 allele by copy number contraction demonstrates the dynamic evolution of this locus and provides the ultimate evidence for causality of the copy number variation of the 4.6 kb intronic sequence.

The efficacy of ritlecitinib, an oral JAK3/TEC family kinase inhibitor, on active and stable lesions was evaluated in patients with active non-segmental vitiligo in a phase 2b trial (NCT03715829). Patients were randomized to placebo or daily ritlecitinib 50 mg (with or without 4-week 100-mg or 200-mg loading dose), 30 mg, or 10 mg for 24 weeks. Active lesions showed greater baseline expression of inflammatory/immune markers IFNG and CCL5, levels of CD103, and T-cell infiltrates than stable lesions. Patients with more active than stable vitiligo lesions showed higher baseline serum levels of CXCL9 and PD-L1, while patients with more stable than active lesions showed higher baseline serum levels of HO-1. At Week 24, ritlecitinib 50 mg significantly stabilized mean percent change from baseline in depigmentation extent in both active lesions and stable lesions vs. placebo-response, with stable lesions showing greater repigmentation. After 24 weeks of treatment, ritlecitinib 50 mg increased expression of melanocyte markers in stable lesions, while Th1/Th2-related and co-stimulatory molecules decreased significantly in both stable and active lesions. Serum from patients with more active than stable lesions showed decreased levels of ICOS and NK cell activation markers. These data, confirmed at transcription/protein levels, indicate that stable lesion repigmentation occurs early with ritlecitinib, while active lesions require stabilization of inflammation first. ClinicalTrials.gov: NCT03715829.

Serpentine supravenous hyperpigmentation (SSH) describes increased skin pigmentation that develops in the area immediately overlying the vessels through which chemotherapeutic drugs are administered. While SSH can be cosmetically distressing and there are no definitive management options, the literature is severely limited and the variations in clinical presentation, risk factors, and histopathology of SSH across patients are not well understood. We aimed to systematically summarize characteristics from current available data, and thus improve SSH awareness and management. A literature search was conducted in PubMed using specific eligibility criteria through the end of December 2022. Included articles focused on patients who experienced SSH after chemotherapy infusion. Study quality was assessed using a modified Oxford Centre for Evidence-Based Medicine quality rating scheme. Of the 41 articles identified by literature search, 24 met eligibility criteria. Two additional articles were identified through the reference sections of retrieved articles, for 26 articles total. All articles were case reports, representing 28 patients total. Locations of SSH were mostly in the forearm near the site of injection (85%), and the most common associated symptom was erythema. Histopathologic analysis was available for half of cases, the majority of which were inflammatory in nature. The most common inflammatory pattern observed was a vacuolar/lichenoid interface dermatitis. Duration of SSH ranged from days to > 1 year after the chemotherapy was stopped. Six (21%) patients were managed with topical steroids and oral vasodilators, six (21%) patients switched to central venous infusion rather than peripheral infusion, five (18%) patients received only supportive care, three (11%) patients received venous washing with chemotherapy, three (11%) patients stopped chemotherapy, and one (4%) patient reduced the chemotherapy dosage. Ten (36%) patients attained complete resolution, seven (25%) had SSH that was near resolution/fading, and three (11%) had persistent hyperpigmentation. Although SSH often spontaneously resolves once the chemotherapeutic agent is stopped, it can persist in some patients and cause significant distress. As the literature is severely limited and there are no definitive treatments, additional research using more standardized definitions and methods of assessments is necessary to improve characterization of SSH and evaluate potential interventions.

BackgroundDyschromia can be associated with increased production and/or reduced clearance of pigmentation in the skin. Multiple pathways are involved in causality. A novel topical product was recently developed, which contains actives that have been validated through in-vitro and clinical studies to counteract pigmentation related to photodamage, PIH, and melasma. This study further evaluates the safety and efficacy of this product for facial dyschromia during an additional 3-month extension period following the completion of the previous 12-week multi-center trial.  Study Design: Subjects from the previous multi-center trial with mild to severe facial dyschromia at baseline were eligible to participate in this 3-month extension study upon completion of that trial. This extension study evaluated the continued use of the novel topical product with PATH-3 Technology (Alastin Skincare, Carlsbad, CA) over a 3-month period. Subjects who were previously randomized to the novel topical product continued using it and for those previously randomized to hydroquinone 4% discontinued its use. Both cohorts continued daily sunscreen use. Blinded investigators assessed subjects at follow-up visits at 16, 20, and 24 weeks.ResultsTwenty-six (26) subjects completed the extension phase of the pivotal trial, with 13 subjects in each of the AL and HQ-BREAK cohorts. Significant improvements were seen within the AL cohort from weeks 12 to 24 for facial dyschromia (P=0.0158) and skin tone/clarity/evenness (P=0.0067), while there were no significant improvements seen in the HQ-BREAK cohort. The HQ-BREAK cohort had more subjects who worsened with facial dyschromia and skin tone/clarity/evenness. For the mMASI, the HQ-BREAK cohort demonstrated regression at week 24 compared to week 12, while the AL cohort instead experienced continued improvement. This difference was found to be significant (P=0.02). No study-related adverse events were reported for either cohort.  Conclusion: A novel topical product designed to counteract various steps in pigmentation pathways using PATH-3 Technology has been demonstrated to be safe and effective in treating facial dyschromia on a long-term basis. In contrast to the significant rebound experienced by subjects with HQ, the AL cohort continued to demonstrate ongoing improvement. J Drugs Dermatol. 2024;23(1):1266-1270.     doi:10.36849/JDD.7622.

Background: A typical broiler production program includes three feeding phases: Pre-starter (from day 1 to 10), Starter (11-21 days), and Grower (from day 22 to slaughter). The program should allow the bird to express its genetic potential and respond to the nutritional challenges. Objective: To determine the effect of duration of the starter and grower phases on growth performance parameters (feed intake and feed conversion), mortality, skin pigmentation, and carcass yield in broiler chickens. Methods: A total of 1,500 Ross 308 AP male broilers were randomly assigned to five feeding programs with different duration, feed presentation (pellet vs. crumble), and anticoccidial (narasin + nicarbazin vs. salynomicin). The variables evaluated were growth performance (body weight, feed intake, and feed conversion), carcass (weight and yield), breast weight and yield, and skin pigmentation. Statistical evaluations were conducted on d 28 and 40 of age. Results: On d 28 of age, differences (p<0.05) were observed for body weight and feed conversion, but not for feed intake. T4 and T5 resulted in the best weight and feed conversion. Differences (p<0.05) were recorded on d 40 for body weight, with higher values in T4 and T5 compared to T1. Carcass weight differed between T1 and T4 (p<0.05), without difference for carcass or breast performance. The statistical analyses of carcass pigmentation showed an effect on redness ("a") and yellowness ("b") at d 28. Conclusions: Body weight and feed conversion of broilers from d 22 to 28 improve by extending the starter phase one week, using pelleted feed added with an ionophore anticoccidial. Skin pigmentation of broilers at slaughter is not affected by restricting pigment intake for one week. [ABSTRACT FROM AUTHOR]

ABSTRACT In skin, melanin is synthesized and stored in melanosomes. In epidermal melanocytes, melanosomes are transported to and internalized by the neighboring keratinocytes, subsequently leading to skin pigmentation. Ultraviolet (UV) radiation induces the release of acetylcholine (ACh) from keratinocytes, which in turn activates ACh receptors (AChRs) on nearby melanocytes, forming a proposed “skin synapse”. Here, we illustrated that the UV‐induced melanosome release from cultured B16F10 melanoma cells could be mediated by co‐actions of ACh. In the cell cultures, UV exposure robustly elicited melanosome release. Applied bethanechol (BeCh), an agonist of muscarinic AChR (mAChR), could significantly enhance the release. In parallel, the intracellular Ca2+ mobilization was regulated. The applied antagonists of M1 and/or M3 mAChRs could block the UV‐induced melanosome release and the mobilization of intracellular Ca2+. The phosphorylation of PKC, triggered by UV and BeCh treatments, could be suppressed by the applied mAChR antagonists. The expressions of tethering complex for exocytosis, for example, Sec8, Exo70, and Rab11b, as well as synaptotagmin, were increased under UV exposure together with mAChR agonist: The inductions were fully abolished by M1 or M3 antagonist. Here, we hypothesize that the cholinergic signaling is playing roles in UV‐induced exocytosis of melanosomes. [ABSTRACT FROM AUTHOR]

Skin pigmentation typically arises from the excessive secretion and accumulation of melanin, resulting in a darker complexion compared to normal skin. Currently, the local application of chemical drugs is a first-line strategy for pigmentation disorders, but the safety and efficacy of drugs still cannot meet clinical treatment needs. For long-term and safe medication, researchers have paid attention to natural products with higher biocompatibility. This article begins by examining the pathogenesis and treatment approaches of skin pigmentation diseases and summarizes the research progress and mechanism of natural products with lightening or whitening effects that are clinically common or experimentally proven. Moreover, we outline the novel formulations of natural products in treating pigmentation disorders, including liposomes, nanoparticles, microemulsions, microneedles, and tocosomes. Finally, the pharmacodynamic evaluation methods in the study of pigmentation disorder were first systematically analyzed. In brief, this review aims to collect natural products for skin pigmentation treatment and investigate their formulation design and efficacy evaluation to provide insights for the development of new products for this complex skin disease. [ABSTRACT FROM AUTHOR]

Observational studies have revealed associations between various dietary factors and skin conditions. However, the causal relationship between diet and skin condition is still unknown. Data on 17 dietary factors were obtained from the UK Biobank. Data on four skin conditions were derived from the UK Biobank and another large-scale GWAS study. Genetic predictions suggested that the intake of oily fish was associated with a lower risk of skin aging (OR: 0.962, P = 0.036) and skin pigmentation (OR: 0.973, P = 0.033); Tea intake was associated with a lower risk of skin pigmentation (OR: 0.972, P = 0.024); Salad/raw vegetables intake was associated with a lower risk of keratinocyte skin cancer (OR: 0.952, P = 0.007). Coffee intake was associated with increased risk of skin aging (OR: 1.040, P = 0.028); Pork intake was associated with increased risk of skin aging (OR: 1.134, P = 0.020); Beef intake was associated with increased risk of cutaneous melanoma (OR: 1.013, P = 0.016); Champagne plus white wine intake was associated with increased risk of cutaneous melanoma (OR: 1.033, P = 0.004); Bread intake was associated with increased risk of keratinocyte skin cancer (OR: 1.026, P = 0.013). Our study results indicate causal relationships between genetically predicted intake of oily fish, tea, salad/raw vegetables, coffee, pork, beef, champagne plus white wine, and bread and skin conditions. [ABSTRACT FROM AUTHOR]

Vitamin D plays a critical role in many physiological functions, including calcium metabolism and musculoskeletal health. This commentary aims to explore the intricate relationships among skin complexion, race, and 25-hydroxyvitamin D (25[OH]D) levels, focusing on challenges the Endocrine Society encountered during clinical practice guideline development. Given that increased melanin content reduces 25(OH)D production in the skin in response to UV light, the guideline development panel addressed the potential role for 25(OH)D screening in individuals with dark skin complexion. The panel discovered that no randomized clinical trials have directly assessed vitamin D related patient-important outcomes based on participants' skin pigmentation, although race and ethnicity often served as presumed proxies for skin pigmentation in the literature. In their deliberations, guideline panel members and selected Endocrine Society leaders underscored the critical need to distinguish between skin pigmentation as a biological variable and race and ethnicity as socially determined constructs. This differentiation is vital to maximize scientific rigor and, thus, the validity of resulting recommendations. Lessons learned from the guideline development process emphasize the necessity of clarity when incorporating race and ethnicity into clinical guidelines. Such clarity is an essential step toward improving health outcomes and ensuring equitable healthcare practices. [ABSTRACT FROM AUTHOR]

Melasma is a pathology with multifactorial causes that results in hyperpigmentation of sun-exposed areas, particularly facial skin. New treatments targeting the different factors regulating this condition need to be effective with and have limited adverse effects. Here, we describe a novel combination of two natural compounds (apigenin and phloretin) that has synergistic effects regulating melanogenesis in vitro. Both compounds inhibit Wnt-stimulated melanogenesis and induce autophagy in melanocytes. Apigenin induces DKK1, a Wnt pathway inhibitor, and reduces VEGF, a melanogenesis and proangiogenic factor, in fibroblasts. Moreover, apigenin induces miR-675, a melanogenesis inhibitor miRNA that is reduced in melasma skin in melanocytes. Both compounds showed senomorphic effects by regulating extracellular-matrix-related genes in senescent fibroblasts. Topical application of the compounds also showed significant melanin reduction in a reconstructed human epidermis after 7 days. Thus, the combination of apigenin and phloretin shows promising results as an effective topical treatment of skin hyperpigmentation conditions. [ABSTRACT FROM AUTHOR]

Objectives: To use portable colorimetry to quantify color differences between facial skin and potential three head and neck microvascular free tissue transfer (MFTT) donor sites—radial forearm (RF), anterolateral thigh (ALT), and fibula (FF)—and compare these differences by pigmentation of the donor site skin and self‐identified race. Methods: In this cross‐sectional cohort study, healthy volunteers consented to handheld colorimeter measurements at the three potential MFTT donor sites (RF, ALT, FF) to quantify color match to the facial skin using the CIE color space (DeltaE). The comparison of ipsilateral to contralateral cheek served as control for measurements. Cross‐sectional measurements in healthy volunteers were then compared to measurements obtained in postoperative head and neck MFTT patients. Results: DeltaE measurements were obtained for 128 healthy controls and 24 postoperative patients (N = 152). With increasing lightness (decreased pigmentation) of the skin at the donor site, the color match significantly worsened (higher DeltaE) across all potential MFTT donor sites (all p < 0.05). DeltaE from healthy controls closely approximated postoperative color match measurements in patients who underwent cervicofacial MFTT (DeltaE RF: 5.3 vs. 6.0, p = 0.432; DeltaE ALT: 6.2 vs. 6.4, p = 0.822; DeltaE FF: 6.0 vs. 6.4, p = 0.806). Conclusion: Patients with decreased skin pigmentation who are undergoing head and neck MFTT may experience worse color discrepancy between cervicofacial skin and the transferred skin paddle than those with more pigmented skin. Portable colorimetry may identify patients who could benefit from interventions such as dermis‐resected free tissue reconstruction with skin grafting to improve postoperative appearance. Level of Evidence: 3 Laryngoscope, 134:3581–3586, 2024 [ABSTRACT FROM AUTHOR]

Abstract Skin pigmentation is negatively associated with circulating vitamin D (VD) concentration. Therefore, genetic factors involved in skin pigmentation could influence the risk of vitamin D deficiency (VDD). We evaluated the impact genetic variants related to skin pigmentation on VD in Mexican population. This cross-sectional analysis included 848 individuals from the Health Worker Cohort Study (ratio males to females ~ 1:3). Eight genetic variants: rs16891982 (SLC45A2), rs12203592 (IRF4), rs1042602 and rs1126809 (TYR), rs1800404 (OCA2), rs12913832 (HERC2), rs1426654 (SLC24A5), and rs2240751 (MFSD12); involved in skin pigmentation were genotyped. Skin pigmentation was assessed by self-report. Linear and logistic regression were used to assess the association between the variants of interest and VD and VDD, as appropriate. In our study, eight genetic variants were associated with skin pigmentation. A genetic risk score built with the variants rs1426654 and rs224075 was associated with lower VD levels (β = − 1.38, 95% CI − 2.59, − 0.17, p = 0.025). Nevertheless, when examining gene–gene interactions, we observed that rs2240751 × rs12203592 were associated with VD levels (P interaction = 0.021). Whereas rs2240751 × rs12913832 (P interaction = 0.0001) were associated with VDD. Our results suggest that skin pigmentation-related gene variants are associated with lower VD levels in Mexican population. These results underscore the importance of considering genetic interactions when assessing the impact of genetic polymorphisms on VD levels.

Abstract Hyperspectral imaging (HSI) is a new emerging modality useful for the noncontact assessment of free flap perfusion. This measurement technique relies on the optical properties within the tissue. Since the optical properties of hemoglobin (Hb) and melanin overlap, the results of the perfusion assessment and other tissue-specific parameters are likely to be distorted by the melanin, especially at higher melanin concentrations. Many spectroscopic devices have been shown to struggle with a melanin related bias, which results in a clinical need to improve non-invasive perfusion assessment, especially for a more pigmented population. This study investigated the influence of skin tones on tissue indices measurements using HSI. In addition, other factors that might affect HSI, such as age, body mass index (BMI), sex or smoking habits, were also considered. Therefore, a prospective feasibility study was conducted, including 101 volunteers from whom tissue indices measurements were performed on 16 different body sites. Skin tone classification was performed using the Fitzpatrick skin type classification questionnaire, and the individual typology angle (ITA) acquired from the RGB images was calculated simultaneously with the measurements. Tissue indices provided by the used HSI-device were correlated to the possible influencing factors. The results show that a dark skin tone and, therefore, higher levels of pigmentation influence the HSI-derived tissue indices. In addition, possible physiological factors influencing the HSI-measurements were found. In conclusion, the HSI-based tissue indices can be used for perfusion assessment for people with lighter skin tone levels but show limitations in people with darker skin tones. Furthermore, it could be used for a more individual perfusion assessment if different physiological influencing factors are respected.

Skin pigmentation is negatively associated with circulating vitamin D (VD) concentration. Therefore, genetic factors involved in skin pigmentation could influence the risk of vitamin D deficiency (VDD). We evaluated the impact genetic variants related to skin pigmentation on VD in Mexican population. This cross-sectional analysis included 848 individuals from the Health Worker Cohort Study (ratio males to females ~ 1:3). Eight genetic variants: rs16891982 (SLC45A2), rs12203592 (IRF4), rs1042602 and rs1126809 (TYR), rs1800404 (OCA2), rs12913832 (HERC2), rs1426654 (SLC24A5), and rs2240751 (MFSD12); involved in skin pigmentation were genotyped. Skin pigmentation was assessed by self-report. Linear and logistic regression were used to assess the association between the variants of interest and VD and VDD, as appropriate. In our study, eight genetic variants were associated with skin pigmentation. A genetic risk score built with the variants rs1426654 and rs224075 was associated with lower VD levels (β = − 1.38, 95% CI − 2.59, − 0.17, p = 0.025). Nevertheless, when examining gene–gene interactions, we observed that rs2240751 × rs12203592 were associated with VD levels (P interaction = 0.021). Whereas rs2240751 × rs12913832 (P interaction = 0.0001) were associated with VDD. Our results suggest that skin pigmentation-related gene variants are associated with lower VD levels in Mexican population. These results underscore the importance of considering genetic interactions when assessing the impact of genetic polymorphisms on VD levels. [ABSTRACT FROM AUTHOR]

Southern flounder skin pigmentation is a critical phenotypic characteristic for this species' survival in the natural environment. Normal pigmentation allows rapid changes of color for concealment to capture prey and UV light protection. In contrast, highly visible hypopigmented pseudo-albinos exhibit a compromised immune system and are vulnerable to predation, sensitive to UV exposure, and likely have poor survival in the wild. Skin and brain tissue samples from normally pigmented and hypopigmented individuals were analyzed with next-generation RNA sequencing. A total of 1,589,613 transcripts were used to identify 952,825 genes to assemble a de novo transcriptome, with 99.43% of genes mapped to the assembly. Differential gene expression and gene enrichment analysis of contrasting tissues and phenotypes revealed that pseudo-albino individuals appeared more susceptible to environmental stress, UV light exposure, hypoxia, and osmotic stress. The pseudo-albinos' restricted immune response showed upregulated genes linked to cancer development, signaling and response, skin tissue formation, regeneration, and healing. The data indicate that a modified skin collagen structure likely affects melanocyte differentiation and distribution, generating the pseudo-albino phenotype. In addition, the comparison of the brain transcriptome revealed changes in myelination and melanocyte stem cell activity, which may indicate modified brain function, reduced melanocyte migration, and impaired vision. [ABSTRACT FROM AUTHOR]

Background and Aim: Melanocytes are cells in the skin, hair, and eyes that generate pigment called melanin, which is primarily responsible for the pigmentation of these structures. These melanocytes, known as the Cochlear Melanocyte, are also present in the human ears (especially in the cochlea) and play a significant role in fostering endocochlear potential and preventing the odds of hearing loss. The current study investigated the relationship of skin pigment with cochlear function through distortion product otoacoustic emission in Indian skin type. Methods: A total of 120 participants aged between 17 to 25 were included using a purposive sampling technique. The subjects were further grouped based on a questionnaire on Fitzpatrick Skin Phototype (FSP) developed by Thomas Fitzpatrick (1975) and categorized as type III- type VI suitable for Indian skin types. Along with routine audiometric evaluations, the cochlear functioning was assessed using distortion product otoacoustic emissions. The standard group research design was used, and as data was normally distributed, multivariate analysis of variance was used to compare across groups. Results: The results of multivariate analysis of variance (MANOVA) showed no significant differences across the four groups for both amplitude and the slope of distortion product otoacoustic emissions. Conclusion: The present study using otoacoustic emissions revealed that the skin pigmentation did not affect cochlear functioning in the Indian population (type III through type VI) as seen in type I and II. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging (HSI) is a new emerging modality useful for the noncontact assessment of free flap perfusion. This measurement technique relies on the optical properties within the tissue. Since the optical properties of hemoglobin (Hb) and melanin overlap, the results of the perfusion assessment and other tissue-specific parameters are likely to be distorted by the melanin, especially at higher melanin concentrations. Many spectroscopic devices have been shown to struggle with a melanin related bias, which results in a clinical need to improve non-invasive perfusion assessment, especially for a more pigmented population. This study investigated the influence of skin tones on tissue indices measurements using HSI. In addition, other factors that might affect HSI, such as age, body mass index (BMI), sex or smoking habits, were also considered. Therefore, a prospective feasibility study was conducted, including 101 volunteers from whom tissue indices measurements were performed on 16 different body sites. Skin tone classification was performed using the Fitzpatrick skin type classification questionnaire, and the individual typology angle (ITA) acquired from the RGB images was calculated simultaneously with the measurements. Tissue indices provided by the used HSI-device were correlated to the possible influencing factors. The results show that a dark skin tone and, therefore, higher levels of pigmentation influence the HSI-derived tissue indices. In addition, possible physiological factors influencing the HSI-measurements were found. In conclusion, the HSI-based tissue indices can be used for perfusion assessment for people with lighter skin tone levels but show limitations in people with darker skin tones. Furthermore, it could be used for a more individual perfusion assessment if different physiological influencing factors are respected. [ABSTRACT FROM AUTHOR]

The reader will come to appreciate that: • Race-based disparities in pulse oximetry have been reported in large retrospective database studies involving adults and recently in pediatric populations. • Pulse oximeters overestimate oxygen saturation in Black compared to other races, particularly in hypoxic states. • Role of skin pigmentation and other dermatological factors that may vary between racial groups has not been evaluated. • Defining mechanisms of this inaccuracy is critical to addressing this disparity in pulse oximeter performance. Race-based and skin pigmentation-related inaccuracies in pulse oximetry have recently been highlighted in several large electronic health record-based retrospective cohort studies across diverse patient populations and healthcare settings. Overestimation of oxygen saturation by pulse oximeters, particularly in hypoxic states, is disparately higher in Black compared to other racial groups. Compared to adult literature, pediatric studies are relatively few and mostly reliant on birth certificates or maternal race-based classification of comparison groups. Neonates, infants, and young children are particularly susceptible to the adverse life-long consequences of hypoxia and hyperoxia. Successful neonatal resuscitation, precise monitoring of preterm and term neonates with predominantly lung pathology, screening for congenital heart defects, and critical decisions on home oxygen, ventilator support and medication therapies, are only a few examples of situations that are highly reliant on the accuracy of pulse oximetry. Undetected hypoxia, especially if systematically different in certain racial groups may delay appropriate therapies and may further perpetuate health care disparities. The role of biological factors that may differ between racial groups, particularly skin pigmentation that may contribute to biased pulse oximeter readings needs further evaluation. Developmental and maturational changes in skin physiology and pigmentation, and its interaction with the operating principles of pulse oximetry need further study. Importantly, clinicians should recognize the limitations of pulse oximetry and use additional objective measures of oxygenation (like co-oximetry measured arterial oxygen saturation) where hypoxia is a concern. [ABSTRACT FROM AUTHOR]

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ObjectivesU.S. Latino populations are diverse. Research on racial identity, skin tone, and Latino health is imperative for understanding and combating racism and colorism. We examined differences in memory performance: among non-Latinos and Latinos who identified as Black, other, and White in the United States and then among Puerto Ricans in Boston whose skin tones ranged from dark, medium, light to "white."MethodsWe used 2010 Health and Retirement Study and 2004 Boston Puerto Rican Health Survey data, respectively, to examine racial and color differences in memory performance among 50 and older adults in the United States and Puerto Rican older adults in Boston. We applied ordinary least squares regression to immediate and delayed word recall test scores and adjusted for education, health conditions, and health behaviors.ResultsIn adjusted models, White non-Latinos had better memory performance than White Latinos. Black Latinos, other Latinos, and Black non-Latinos had lower delayed word recall scores than White Latinos. Black Latinos and Black non-Latinos had similar scores. Intra-Latino racial disparities endured despite the inclusion of education and other covariates. Among Puerto Ricans in Boston, medium-toned individuals had higher scores than "white"-toned individuals.DiscussionFindings support the importance of examining self-identified race and skin tone in Latino aging research. Further investigation is needed to understand the stubborn intra-Latino racial disparities in memory performance and surprising adverse cognitive performance among "white"-toned relative to darker-toned Puerto Ricans in Boston.

Mental healthcare disparities are routinely documented, yet they remain wider than in most other areas of healthcare services and common mental disorders (depression and anxiety) continue to be one of the highest health burdens for older people of color. To address disparities in mental health services for older people of color, the narrative must move beyond simply documenting these inequities and attain a better understanding of the internalized, interpersonal, systemic, and medical racism that have harmed these communities and excluded them from its services in the first place. It is imperative that researchers, clinicians, and policymakers acknowledge the realities of racism and discrimination as leading causes of mental healthcare disparities. Therefore, this review is a call-to-action. Authors adopt an antiracist and health equity lens in evaluating the differing needs of Blacks/African-Americans, Asian Americans, and Latinos by exploring psychiatric comorbidity, experiences with seeking, accessing, and engaging in treatment, and the unique cultural and psychosocial factors that affect treatment outcomes for these diverse groups. Further, authors offer researchers and practitioners tangible tools for developing and implementing culturally-sensitive, mental health focused interventions for older people of color with special attention placed on cultural adaptations, models of care, prevention, and practical strategies that can be implemented to reduce disparities and increase equity in mental healthcare.

BackgroundKey cellular players regulating human skin pigmentation include melanocytes in the epidermis that synthesize melanin, neighboring keratinocytes that receive and distribute melanin in the upper layers, and fibroblasts in the dermis that affect overlying melanocytes and keratinocytes. In addition, endocrine factors from the blood supply (endothelial cells) and inflammation-related factors play a role. Thus, new strategies for affecting pigmentation need to consider these multiple cell lines to adequately cover various causes and disease processes associated with hyperpigmentation.MethodsPathophysiologic mechanisms and cellular pathways involved in melanogenesis were thoroughly reviewed with particular emphasis on the cellular interplay involved in the process. A complex system of interlinking and independent pathways was defined and described demonstrating differing pathways for altered pigmentary disorders - melasma associated with endothelial cell interactions; post inflammatory hyperpigmentation associated with keratinocyte inflammatory mediators (PGE2 in particular); and photodamage involving all 4 cell types. In vitro validation studies were then undertaken to define differing cell group gene expression profiles with selected peptides and other active agents. Melanocytic production of pigment was then tested with these agents to identify key potential players capable of limiting pigmentation.ResultsHexapeptide-12 and lactoferrin (melanocytes), Hexapeptide-11 (in keratinocytes), and phosphatidylserine (endothelial cells) were identified as major inhibitors of melanogenesis based on their gene expression profiles. This was confirmed by secondary melanin production tests performed on melanocytic lines. Additional active agents were also identified as inhibitors of melanocytic production of melanin, and together, these constituents formed the basis for a novel formulation for use in pigmentary disorders.ConclusionA comprehensive scientific narrative of the various facets relating to pigmentation has been presented including differing pathways affecting varied cell lines that effect pigment production. Based on this concept, actives were tested using gene expression studies as well as in vitro melanogenic model testing in different cell lines. Using this novel multi-faceted approach, we have selected and validated a series of active agents to be used in a formulation targeting the complex problem of hyperpigmentation. J Drugs Dermatol. 2022;21(11):1206-1220. doi:10.36849/JDD.7013.

Extracellular vesicles (EVs) facilitate the transfer of proteins, lipids, and genetic material between cells and are recognized as an additional mechanism for sustaining intercellular communication. In the epidermis, the communication between melanocytes and keratinocytes is tightly regulated to warrant skin pigmentation. Melanocytes synthesize the melanin pigment in melanosomes that are transported along the dendrites prior to the transfer of melanin pigment to keratinocytes. EVs secreted by keratinocytes modulate pigmentation in melanocytes [(A. Lo Cicero et al., Nat. Commun. 6, 7506 (2015)]. However, whether EVs secreted by keratinocytes contribute to additional processes essential for melanocyte functions remains elusive. Here, we show that keratinocyte EVs enhance the ability of melanocytes to generate dendrites and mature melanosomes and promote their efficient transfer. Further, keratinocyte EVs carrying Rac1 induce important morphological changes, promote dendrite outgrowth, and potentiate melanin transfer to keratinocytes. Hence, in addition to modulating pigmentation, keratinocytes exploit EVs to control melanocyte plasticity and transfer capacity. These data demonstrate that keratinocyte-derived EVs, by regulating melanocyte functions, are major contributors to cutaneous pigmentation and expand our understanding of the mechanism underlying skin pigmentation via a paracrine EV-mediated communication. [ABSTRACT FROM AUTHOR]

The heightened awareness of ethnic dermatology aligns with the growing prevalence of skin of color communities globally, where hyperpigmentation disorders pose a common dermatological challenge. Effectively addressing dermal pigmentation is challenging due to its resistance to conventional therapies and its association with impaired quality of life. This underscores the need for effective treatments and a thorough grasp of laser advancements. A relevant literature search spanning the last 7 years across the PubMed database reveals core studies, challenges, and the evolution of laser technologies tailored for various forms of congenital and acquired dermal hyperpigmentation in skin of color. This comprehensive review explores the mechanisms, applications, and recommendations for pigmentary laser technologies, highlighting the key role of Q-switched lasers in their established millisecond/ nanosecond forms and emerging picosecond lasers, fractional non-ablative and ablative lasers, Intense Pulsed Light, etc. The summary of evidence includes studies on dermal melanocytosis (nevus of Ota and Hori's nevus), tattoos, acquired dermal macular hyperpigmentation, etc., and also entities with mixed epidermal–dermal components, such as melasma and post-inflammatory hyperpigmentation. The review offers valuable insights for clinicians to make informed decisions based on diagnosis, skin type, and the latest technologies to optimize results and minimize complications, especially in darker Fitzpatrick skin types. In their five-year study with 122 Indian patients, the authors applied specific laser combinations for diverse dermal melanoses, including tattoos, dermal/mixed melasma, acquired dermal macular hyperpigmentation, and dermal nevi. Substantial pigmentation reduction, subjectively assessed by both physicians and patients, was observed across all groups. A one-way ANOVA indicated a significant difference in mean improvement scores across various pigmentary conditions (F = 3.39, p = 0.02), with melasma patients exhibiting a significantly higher improvement score than tattoos (p = 0.03). The results affirmed the safety and efficacy of sequential laser therapy for dermal pigmentation in skin of color, advocating for flexibility in approach while maintaining the rationale behind the laser sequences. Despite advancements, challenges persist, and gaps in the current literature are identified. In conclusion, this summary highlights the ongoing pursuit of optimal protocols in dermatological laser treatments for dermal melanoses, offering valuable insights for future research and clinical practice. [ABSTRACT FROM AUTHOR]

Objectives: Cutaneous hyperpigmentation is one of the main adverse effects encountered in patients undergoing leprosy treatment with multidrug therapy (WHO‐MDT). This adverse effect has been described as intolerable and capable of contributing to social stigma. The objectives of this study were to quantify the variation in skin colour induced by clofazimine during and after treatment and to assess the related stigma. Methods: This observational cross‐sectional study objectively measured skin colour in 51 patients by reading the individual typology angle (ITA°) with a spectrophotometer, followed by the application of the Stigma Scale of the Explanatory Model Interview Catalogue (EMIC). Results: Skin hyperpigmentation was observed in 100% of the individuals. They showed more negative ITA° values in lesion areas than non‐lesion areas, particularly in sun‐exposed regions. Clofazimine‐induced cutaneous hyperpigmentation was not homogeneous and seemed to follow the lesion locations. The mean EMIC score was 18.8 points. Conclusion: All patients presented skin hyperpigmentation caused by clofazimine, detectable through spectrophotometry. Hyperpigmentation strongly impacted the social domain, indicating the intersectionality of disease and skin colour stigma, contributing to the social isolation of these patients. Health authorities should consider the negative impact of clofazimine on treatment adherence. [ABSTRACT FROM AUTHOR]

Purpose: Evaluate the SpO2-SaO2 difference between Black and White volunteer subjects having a low perfusion index (Pi) compared to those having a normal Pi. Methods: The Pi data were abstracted from electronic files collected on 7183 paired SpO2-SaO2 samples (3201 Black and 3982 White) from a recently reported desaturation study of 75 subjects (39 Black and 36 White) where SaO2 values were sequentially decreased from 100 to 70%. The Pi values from that dataset were divided into two groups (Pi ≤ 1 or Pi > 1) for analysis. A Pi value ≤ 1 was considered "low perfusion" and a Pi value > 1 was considered "normal perfusion". Statistical calculations included values of bias (mean difference of SpO2-SaO2), precision (standard deviation of the difference), and accuracy (root-mean-square error [ARMS]). During conditions of low perfusion (Pi ≤ 1, range [0.1 to 1]), overall bias and precision were + 0.48% ± 1.59%, while bias and precision were + 0.19 ± 1.53%, and + 0.91 ± 1.57%, for Black and White subjects, respectively. Results: During normal perfusion (Pi > 1, range [1 to 12]), overall bias and precision were + 0.18% ± 1.34%, while bias and precision were -0.26 ± 1.37%, and − 0.12 ± 1.31%, for Black and White subjects, respectively. ARMS was 1.37% in all subjects with normal perfusion and 1.64% in all subjects with low perfusion. Conclusion: Masimo SET® pulse oximeters with RD SET® sensors are accurate for individuals of both Black and White races when Pi is normal, as well as during conditions when Pi is low. The ARMS for all conditions studied is well within FDA standards. This study was conducted in healthy volunteers during well-controlled laboratory desaturations, and results could vary under certain challenging clinical conditions. [ABSTRACT FROM AUTHOR]

Background: Ethnic inequalities in maternal and neonatal health in the UK are well documented. Concerns exist regarding the use of skin colour in neonatal assessments. Healthcare professionals should be trained to recognise symptoms of diverse skin tones, and comprehensive, and inclusive guidance is necessary for the safe assessment of all infants. Disparities in healthcare provision have been emphasised during the COVID-19 pandemic, and additional research is needed to determine whether such policies adequately address ethnic minority neonates. Methods: A desktop search included searches of guidance produced for the United Kingdom (UK). Further searches of the Cochrane and World Health Organization (WHO) were used to identify any international guidance applicable in the UK context. Results: Several policies and one training resource used descriptors 'pink,' 'pale,' 'pallor,' and 'blue' about neonatal skin and mucous membrane colour. No policies provided specific guidance on how these colour descriptors may appear in neonates with different skin pigmentation. Only the NICE guidance and HEE e-learning resource acknowledged the challenges of assessing jaundice in infants with diverse skin tones, while another guideline noted differences in the accuracy of bilirubin measurements for the assessment of jaundice. Three policies and one training resource advised against relying on visual observation of skin colour when diagnosing neonatal conditions. The training resource included images of ethnic minority neonates, although most images included white infants. Conclusions: Inadequate consideration of ethnicity in UK policy and training perpetuates disparities, leading to inaccurate assessments. A review is needed for inclusivity in neonatal care, regardless of skin pigmentation. [ABSTRACT FROM AUTHOR]

Background: Current methods for evaluating efficacy of cosmetics have limitations because they cannot accurately measure changes in the dermis. Skin sampling using microneedles allows identification of skin‐type biomarkers, monitoring treatment for skin inflammatory diseases, and evaluating efficacy of anti‐aging and anti‐pigmentation products. Materials and methods: Two studies were conducted: First, 20 participants received anti‐aging treatment; second, 20 participants received anti‐pigmentation treatment. Non‐invasive devices measured skin aging (using high‐resolution 3D‐imaging in the anti‐aging study) or pigmentation (using spectrophotometry in the anti‐pigmentation study) at weeks 0 and 4, and adverse skin reactions were monitored. Skin samples were collected with biocompatible microneedle patches. Changes in expression of biomarkers for skin aging and pigmentation were analyzed using qRT‐PCR. Results: No adverse events were reported. In the anti‐aging study, after 4 weeks, skin roughness significantly improved in 17 out of 20 participants. qRT‐PCR showed significantly increased expression of skin‐aging related biomarkers: PINK1 in 16/20 participants, COL1A1 in 17/20 participants, and MSN in 16/20 participants. In the anti‐pigmentation study, after 4 weeks, skin lightness significantly improved in 16/20 participants. qRT‐PCR showed significantly increased expression of skin‐pigmentation‐related biomarkers: SOD1 in 15/20 participants and Vitamin D Receptor (VDR) in 15/20 participants. No significant change in TFAP2A was observed. Conclusion: Skin sampling and mRNA analysis for biomarkers provides a novel, objective, quantitative method for measuring changes in the dermis and evaluating the efficacy of cosmetics. This approach complements existing evaluation methods and has potential application in assessing the effectiveness of medical devices, medications, cosmeceuticals, healthy foods, and beauty devices. [ABSTRACT FROM AUTHOR]

Background: Understanding the variances in visual skin changes across all skin tones is important in clinical care. However, the experiences of those teaching skin assessment to pre- and post-registrant nurses are unknown. Aims: To determine the barriers and facilitators experienced in teaching skin assessment across a range of skin tones to pre- and post-registrant nurses. Methods: A cross-sectional, mixed-methods online survey was undertaken throughout February and March 2023 based on the Theoretical Domains Framework of behaviour change. Findings: In this self-selecting sample, most participants were aware of why it was important to include all skin tones when teaching skin assessment and were professionally motivated to include this in their practice. However, resources and support are needed to overcome an unconscious bias in teaching skin tone diversity, resulting in a lack of availability of good quality photographs and educator confidence in their own skills. Educators not considering skin tone when selecting patient cases and relying on people with dark skin tones to highlight where practice is not inclusive may also lead to insufficient exposure for students. Conclusion: There is some awareness of the importance of including diverse skin tones in teaching, but further education and resources are needed. [ABSTRACT FROM AUTHOR]

Purpose: Recent reports that pulse oximeters may overestimate oxygen saturation in individuals with darker skin pigmentation have prompted concerns from regulatory authorities regarding racial bias. We investigated the performance of TruSignal SpO2 sensors (GE Healthcare, Helsinki, Finland) in adults with varying skin pigmentation. Methods: A retrospective study was conducted using a set of pooled assessments of SpO2/SaO2 measurements from nine studies to assess bias, accuracy (Arms), and precision of TruSignal sensors in healthy adults under induced hypoxia. Subgroup analyses were performed based on oxygen saturation levels (band 1, ≥ 70 and ≤ 80%; band 2, > 80 and ≤ 90%; band 3, > 90 and ≤ 100%). Results: Of the 10,800 data points from 131 individuals, 8,202 (75.9%) and 2,598 (24.1%) were assigned to the light and dark pigment groups, respectively. Bias was 0.14% overall and less than 1% across oxygenation bands. The difference in bias between dark and light pigment groups was statistically significant at the low oxygenation band with SpO2 ≥ 70 and ≤ 80% (+ 0.58% and + 0.30% respectively; p = 0.0035). Throughout the saturation range, Arms was 1.64% in the light and 1.71% in the dark pigment group, within device specifications and regulatory requirements. Oxygenation was the dominating factor in stepwise ANOVA modeling. The mixed model also showed that bias was strongly affected by the oxygenation range. Conclusion: TruSignal sensors demonstrated higher bias at lower oxygen saturation, with less than 0.5% difference between pigment groups. These findings raise new questions, such as ways to improve pulse oximetry measurements during challenging clinical conditions, including low perfusion. [ABSTRACT FROM AUTHOR]

Background and Aims: The protection for ultra‐long UVA1 is lacked in the market, posing potential damage from ultra‐long UVA1 irradiation. The study aims to evaluate the efficacy of a sunscreen containing multiple components, especially Mexoryl® 400 for improving skin barrier function and reducing melanin content. Methods: This single‐center study included adults with sensitive and normal skin in China in November 2022. Participants received the test sunscreen for 4 weeks. Melanin and hemoglobin content, sebum secretion skin hydration, and trans‐epidermal water loss were evaluated at T0d, T7d, and T28d. The self‐assessment was done at T15min, T7d, and T28d. Results: Sixty participants were included, including 30 self‐claimed sensitive skin in the sunscreen group. The sunscreen demonstrated significant improvements in skin parameters. Skin redness reduced by 9.84% at T28d, sebum content in the forehead area decreased by 22.70% at T28d, and skin stratum corneum hydration increased by 38.44% at T28d, p < 0.001 respectively. Most notably, skin melanin content significantly reduced by 13.49% after 4 weeks' usage (p < 0.001). No adverse reactions were reported in either group. Conclusions: The study sunscreen improved the skin condition by decreasing the melanin content, regulating skin barrier function, and achieving a balance of skin hydration and sebum secretion. [ABSTRACT FROM AUTHOR]

Kang Nien How,1,2,&ast; Wen Chung Ho,1,2,&ast; Meroshini Sundaran,1,2,&ast; Wan Syazween Lyana Wan Ahmal Kammal,1,2,&ast; Poh Ying Lim,3 Wilson Chew4 1Dermatology Unit, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 2Hospital Sultan Abdul Aziz Shah, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 3Department of Community Health, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 4Beiersdorf (Malaysia) Sdn Bhd, Petaling Jaya, Selangor, Malaysia&ast;These authors contributed equally to this workCorrespondence: Kang Nien How, Dermatology Unit, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, 43400, Malaysia, Tel +603 97695601, Email hkangnien@upm.edu.myPurpose: We aim to evaluate the effectiveness and tolerability of a sunscreen formulation containing licochalcone A (LicA) and L-carnitine (LC) as an adjuvant to adapalene in the management of acne and post-acne pigmentation (PAH).Patients and Methods: A randomized, double-blind, active comparator-controlled trial of 51 patients aged 18 years or older with a clinical diagnosis of mild-to-moderate acne vulgaris was conducted at the Hospital Sultan Abdul Aziz Shah, Universiti Putra Malaysia. The efficacy and tolerability of once-daily adapalene 1.0% were assessed during the 2-week run-in period. Subsequently, patients were randomized to receive either an add-on investigational LicA-containing sunscreen or niacinamide-containing comparator sunscreen every 4 hourly during daytime for 4 weeks. Patients were followed up at Weeks 2 and 4 to assess for improvement in acne severity, PAH, calorimetric parameters and cutaneous tolerability.Results: Two weeks of adapalene usage significantly improved acne severity; however, up to 52% of patients experienced dryness, burning and stinging. Adding LicA-containing or comparator sunscreens was associated with further improvement in acne severity, PAH and calorimetric parameters at the study endpoint. No significant differences in the cutaneous tolerability profiles were observed between treatment groups. Notably, significantly fewer patients receiving LicA-containing sunscreen developed scaliness at Week 4 compared with those in the comparator group. In addition, more patients receiving LicA-containing sunscreen reported less dryness, burning and stinging reactions than the comparator group. Importantly, more patients receiving LicA-containing sunscreen agreed that their treatment led to excellent improvement than the comparator group; of note, one patient reported that their condition worsened with the receipt of the comparator product.Conclusion: The concurrent use of LicA–containing sunscreen with adapalene may improve the cutaneous tolerance to adapalene among Malaysian patients.Keywords: acne vulgaris, cosmeceuticals, retinoids, sunscreen agents, skin pigmentation

Skin pigmentation typically arises from the excessive secretion and accumulation of melanin, resulting in a darker complexion compared to normal skin. Currently, the local application of chemical drugs is a first-line strategy for pigmentation disorders, but the safety and efficacy of drugs still cannot meet clinical treatment needs. For long-term and safe medication, researchers have paid attention to natural products with higher biocompatibility. This article begins by examining the pathogenesis and treatment approaches of skin pigmentation diseases and summarizes the research progress and mechanism of natural products with lightening or whitening effects that are clinically common or experimentally proven. Moreover, we outline the novel formulations of natural products in treating pigmentation disorders, including liposomes, nanoparticles, microemulsions, microneedles, and tocosomes. Finally, the pharmacodynamic evaluation methods in the study of pigmentation disorder were first systematically analyzed. In brief, this review aims to collect natural products for skin pigmentation treatment and investigate their formulation design and efficacy evaluation to provide insights for the development of new products for this complex skin disease.

IntroductionIn the era of biomedical HIV prevention and treatment technologies, such as treatment as prevention (TasP) and pre-exposure prophylaxis (PrEP), there is momentum to develop and rigorously evaluate interventions focused on PrEP among those at risk for HIV acquisition and antiretroviral therapy (ART) adherence among people living with HIV. While HIV status-specific interventions focused on PrEP or ART provide valuable information, status-segregated interventions can create, perpetuate, and even increase HIV stigma among transgender women of colour and other marginalized communities in the United States (US).DiscussionDue largely to community advocacy, discourses that support status-neutral approaches have emerged in the scientific literature. Although US-based funding mechanisms have typically designated awards focused on a specific HIV status, intervention developers and implementing agencies find creative ways to design and implement status-neutral programmes despite such restrictions. We present our experience with intervention research in New York, Detroit, New Orleans, Puerto Rico and the San Francisco Bay Area, all Ending the HIV Epidemic (EHE) priority jurisdictions. Kickin it with the Gurlz' was developed to be status-neutral through two grants due to community demands for a unifying approach. The Transgender Women Engagement and Entry to (TWEET) Care Project was designed to improve HIV care engagement for transgender women living with HIV, but developers realized the importance of including participants of any HIV status. Healthy Divas was designed for transgender women living with HIV but subsequent implementing agencies prioritized adapting it to be status-neutral. These examples support the urgency of designing, implementing and evaluating status-neutral interventions.ConclusionsCommunity-based organizations strive for inclusivity in their programming and are rightly often reluctant to segregate services based on the HIV status of their clients. As researchers, we have an ethical imperative to work to reduce HIV stigma and respond to the needs of those most impacted by HIV, including transgender women of colour. As such, we call upon funders to develop mechanisms that support the development and testing of HIV status-neutral interventions to reduce HIV stigma and support community building, thereby increasing the possibility of fully realizing the benefits of biomedical HIV prevention and treatment technologies for all.

Depigmenting products are increasingly used to counteract skin hyperpigmentation and related psychosocial issues. This study aimed to compare different depigmenting agents—4-butylresorcinol; bakuchiol; tranexamic acid; ascorbyl glucoside; α-arbutin; and ascorbic acid—for photoreactivity; tyrosinase inhibition; and safety. Photoreactivity was assessed using the Reactive Oxygen Species assay. In vitro tyrosinase inhibition was compared, and cell viability was assessed in B-16V melanocytes to evaluate safety. Results showed 4-butylresorcinol, ascorbyl glucoside, and α-arbutin are non-photoreactive, while for ascorbic acid and bakuchiol it was not possible to reach conclusive results due to the lack of specificity of the ROS assay. 4-Butylresorcinol, acting as a competitive inhibitor, displayed potent tyrosinase inhibition, followed by ascorbic acid and bakuchiol. Both 4-butylresorcinol and bakuchiol reduced cell viability in a concentration-dependent manner. The insights obtained in this work support the development of depigmenting products by providing useful scientific guidance on the photostability, tyrosinase inhibitory efficacy, and skin safety of depigmenting agents. [ABSTRACT FROM AUTHOR]

Background: Most studies have discussed variations in facial skin colour based on age, gender, and anatomical site within a specific ethnic group. However, skin pigmentation on the body is also a concern for many people. Aim: The aim of this study is to gather baseline data for Chinese young females, conduct a comprehensive assessment of body skin pigmentation, and create a body skin pigmentation map. Method: Individual type angle (ITA°) was registered by CL 400 and melanin index (MI) was registered by MX 18 in 100 body points of 20 Chinese females. A total of 12,000 measurements were recorded. Result: Our results showed significant differences among the symmetrical points on both sides of the body, including the clavicle, inner wrists, groin, inner ankle, elbow, armpit, waist side, the space between the thumb and index finger, instep, back shoulder, and popliteal space. Of all the points tested on the body, the points with the most severe skin pigmentation were the back of the neck, the heel, the elbow, and the popliteal space. Conclusion: This is the first comprehensive study of skin pigmentation conducted on the human body. In young Chinese women, the points with the most severe skin pigmentation were the back of the neck, heels, elbows, and the popliteal space. [ABSTRACT FROM AUTHOR]

Background: Melasma results from the imbalance of the mechanisms that regulate skin pigmentation, causing the appearance of hyperpigmented patches. Treatment includes topical and oral agents, chemical peelings, microneedling, and laser therapy. The picosecond laser was developed to minimize pain and skin discoloration, which can sometimes be associated with laser treatments. It emits short pulses of energy that last from 300 to 500 picoseconds, leading to a more significant fragmentation of melanin, with miniminal risk of scarring and thermal lesions in the surrounding skin. Objective: The authors aimed to review the use of picosecond laser in the treatment of melasma and further provide an overview of the other current available options. Conclusions: While the use of picosecond laser for the treatment of melasma has yielded good results, further studies with longer follow-up periods and a higher number of patients are needed. [ABSTRACT FROM AUTHOR]

Background: The observation of color is an integral part of the nursing assessment. However, the current understanding of individual skin qualities and pigmentation has not yet been integrated thoroughly into foundational assessment courses, clinical education, simulation, and textbooks. Evidence Acquisition: Literature is scarce regarding racial groups, skin color, and physical assessment for patients across the lifespan, but even more so for the neonatal population. Historically, many nursing textbooks did not provide visual pictures or observational assessment strategies for the assessment of the Black, Indigenous, and people of color (BIPOC) population. This is improving in some nursing textbooks; however, the descriptors of and visual differences and anticipated assessment findings for the BIPOC population are not comprehensive. Results: Evidence-based assessment findings, which may occur in newborns with varying skin tones/pigmentations, are presented. Implications for Practice and Research: The most essential step to having an accurate assessment is acknowledging the importance of color awareness. Color blindness, while thought to support inclusivity, only contributes to exclusion of one of the most important components of a person's being—their color. [ABSTRACT FROM AUTHOR]

One of the rarest and most unusual iguanas on the planet is the Galápagos pink land iguana (Conolophus marthae). There have been a number of hypotheses on the source of their pink coloration, including that the colour is from blood and a relative lack of dermal pigmentation. We obtained full thickness skin biopsies of three species and compared tissue from darkly pigmented areas and lightly pigmented surfaces. “Pink” areas of pink iguanas are devoid of pigment cells (e.g. melanophores) and the dermal tissue is rich with aggregates of confluent capillaries. This was in sharp contrast to the minimally vascular (only capillaries were observed) dermal areas of the marine and yellow iguanas. The dermal stratum laxum of every biopsy site contained melanophores except for the pink skin of pink iguanas. Interestingly, marine iguanas have a much thicker epidermal stratum germinativum/granulosum, between 2 and 10 cells thick depending on location, compared to the thinner epidermal stratum germinativum/granulosum of land iguanas (one to three cells thick with most areas possessing just one or two cell layers). These microscopic differences might reflect differences in habitat and ecology of the three species. [ABSTRACT FROM AUTHOR]

Summary: Background: Fingertip pulse oximeters are widely available, inexpensive, and commonly used to make clinical decisions in many settings. Device performance is largely unregulated and poorly characterised, especially in people with dark skin pigmentation. Methods: Eleven popular fingertip pulse oximeters were evaluated using the US Food and Drug Administration (FDA) Guidance (2013) and International Organization for Standardization Standards (ISO, 2017) in 34 healthy humans with diverse skin pigmentation utilising a controlled desaturation study with arterial oxygen saturation (SaO 2) plateaus between 70% and 100%. Skin pigmentation was assessed subjectively using a perceived Fitzpatrick Scale (pFP) and objectively using the individual typology angle (ITA) via spectrophotometry at nine anatomical sites. Findings: Five of 11 devices had a root mean square error (ARMS) > 3%, falling outside the acceptable FDA performance range. Nine devices demonstrated worse performance in participants in the darkest skin pigmentation category compared with those in the lightest category. A commonly used subjective skin colour scale frequently miscategorised participants as being darkly pigmented when compared to objective quantification of skin pigment by ITA. Interpretation: Fingertip pulse oximeters have variable performance, frequently not meeting regulatory requirements for clinical use, and occasionally contradicting claims made by manufacturers. Most devices showed a trend toward worse performance in participants with darker skin pigment. Regulatory standards do not adequately account for the impact of skin pigmentation on device performance. We recommend that the pFP and other non-standardised subjective skin colour scales should no longer be used for defining diversity of skin pigmentation. Reliable methods for characterising skin pigmentation to improve diversity and equitable performance of pulse oximeters are needed. Funding: This study was conducted as part of the Open Oximetry Project funded by the Gordon and Betty Moore Foundation, Patrick J McGovern Foundation, and Robert Wood Johnson Foundation. The UCSF Hypoxia Research Laboratory receives funding from multiple industry sponsors to test the sponsors' devices for the purposes of product development and regulatory performance testing. Data in this paper do not include sponsor's study devices. All data were collected from devices procured by the Hypoxia Research Laboratory for the purposes of independent research. No company provided any direct funding for this study, participated in study design or analysis, or was involved in analysing data or writing the manuscript. None of the authors own stock or equity interests in any pulse oximeter companies. Dr Ellis Monk's time utilised for data analysis, reviewing and editing was funded by grant number: DP2MH132941.

Background and Aim: Melanocytes are cells in the skin, hair, and eyes that generate pigment called melanin, which is primarily responsible for the pigmentation of these structures. These melanocytes, known as the Cochlear Melanocyte, are also present in the human ears (especially in the cochlea) and play a significant role in fostering endocochlear potential and preventing the odds of hearing loss. The current study investigated the relationship of skin pigment with cochlear function through distortion product otoacoustic emission in Indian skin type. Methods: A total of 120 participants aged between 17 to 25 were included using a purposive sampling technique. The subjects were further grouped based on a questionnaire on Fitzpatrick Skin Phototype (FSP) developed by Thomas Fitzpatrick (1975) and categorized as type III- type VI suitable for Indian skin types. Along with routine audiometric evaluations, the cochlear functioning was assessed using distortion product otoacoustic emissions. The standard group research design was used, and as data was normally distributed, multivariate analysis of variance was used to compare across groups. Results: The results of multivariate analysis of variance (MANOVA) showed no significant differences across the four groups for both amplitude and the slope of distortion product otoacoustic emissions. Conclusion: The present study using otoacoustic emissions revealed that the skin pigmentation did not affect cochlear functioning in the Indian population (type III through type VI) as seen in type I and II.

Abstract Background and Aims The protection for ultra‐long UVA1 is lacked in the market, posing potential damage from ultra‐long UVA1 irradiation. The study aims to evaluate the efficacy of a sunscreen containing multiple components, especially Mexoryl® 400 for improving skin barrier function and reducing melanin content. Methods This single‐center study included adults with sensitive and normal skin in China in November 2022. Participants received the test sunscreen for 4 weeks. Melanin and hemoglobin content, sebum secretion skin hydration, and trans‐epidermal water loss were evaluated at T0d, T7d, and T28d. The self‐assessment was done at T15min, T7d, and T28d. Results Sixty participants were included, including 30 self‐claimed sensitive skin in the sunscreen group. The sunscreen demonstrated significant improvements in skin parameters. Skin redness reduced by 9.84% at T28d, sebum content in the forehead area decreased by 22.70% at T28d, and skin stratum corneum hydration increased by 38.44% at T28d, p

SignificanceSpatial frequency domain imaging (SFDI) is a wide-field diffuse optical imaging technique for separately quantifying tissue reduced scattering (μs  '  ) and absorption (μa) coefficients at multiple wavelengths, providing wide potential utility for clinical applications such as burn wound characterization and cancer detection. However, measured μs  '   and μa can be confounded by absorption from melanin in patients with highly pigmented skin. This issue arises because epidermal melanin is highly absorbing for visible wavelengths and standard homogeneous light-tissue interaction models do not properly account for this complexity. Tristimulus colorimetry (which quantifies pigmentation using the L  *   "lightness" parameter) can provide a point of comparison between μa, μs  '  , and skin pigmentation.AimWe systematically compare SFDI and colorimetry parameters to quantify confounding effects of pigmentation on measured skin μs  '   and μa. We assess the correlation between SFDI and colorimetry parameters as a function of wavelength.Approachμs  '   and μa from the palm and ventral forearm were measured for 15 healthy subjects with a wide range of skin pigmentation levels (Fitzpatrick types I to VI) using a Reflect RS® (Modulim, Inc., Irvine, California) SFDI instrument (eight wavelengths, 471 to 851 nm). L  *   was measured using a Chroma Meter CR-400 (Konica Minolta Sensing, Inc., Tokyo). Linear correlation coefficients were calculated between L  *   and μs  '   and between L  *   and μa at all wavelengths.ResultsFor the ventral forearm, strong linear correlations between measured L  *   and μs  '   values were observed at shorter wavelengths (R  >  0.92 at ≤659  nm), where absorption from melanin confounded the measured μs  '  . These correlations were weaker for the palm (R

Although the number of Hispanic/Latina women earning medical degrees has increased in recent years, the article by Anaya and colleagues in this issue highlights their stark underrepresentation in the U.S. physician workforce. In this Invited Commentary, the authors provide context on proposed drivers of underrepresentation, including bias, discrimination, harassment, and other structural barriers, which are amplified for women with multiple minoritized identities. They summarize the 2020 National Academies of Sciences, Engineering, and Medicine recommendations for supporting women in science, technology, engineering, mathematics, and medicine (STEMM) fields, including committed leadership, dedicated financial and human resources, data-driven accountability, and use of an intersectional approach to address the challenges faced by individuals who encounter multiple forms of bias and discrimination. The authors also provide additional recommendations and highlight innovative new National Institutes of Health funding opportunities to promote diversity in the scientific workforce. They argue that more research is needed to identify and best implement institutional practices that increase representation and retention of Latina women and other women with minoritized identities in STEMM fields.

External and internal stressors have been found to adversely affect skin health and overall wellness. There is growing interest in the use of anti-inflammatory and antioxidant plant-derived ingredients, such as ashwagandha, saffron, l-theanine, and tocopherol, to mitigate the impact of these stressors. In this study, we evaluate the effectiveness of oral and topical products (InnerCalm and SuperCalm, respectively) that contain naturally derived ingredients on skin redness, skin pigmentation, sleep, and mood in healthy females with Fitzpatrick skin type 1−4 and self-perceived sensitive skin. Subjects were randomized to an oral (oral group), a topical (topical group), or a combination of both the oral and topical interventions (combined group). Standardized photography-based image analysis was used to assess skin redness and pigment. Self-assessments of mood and sleep were measured with the abbreviated profile of mood states (POMS) questionnaire, and the Pittsburgh sleep-quality index (PSQI), respectively. Assessments were made at the baseline, 1-week, 4-weeks, and 8-weeks of the intervention. The average facial redness decreased in the topical group at 8-weeks (p < 0.001) and in the combined group at 4-weeks (p < 0.05) and 8-weeks (p < 0.001), relative to the baseline. The average facial pigmentation decreased in the oral (p < 0.05) and combined (p < 0.05) cohorts at 8-weeks, relative to the baseline. The oral group exhibited an improvement in sleep quality at 1-week relative to the baseline (p < 0.05) and at 8-weeks relative to the baseline (p < 0.05). Finally, the combined group demonstrated improvement in fatigue (p < 0.01) and confusion (p < 0.05) at 8-weeks relative to the baseline, though total mood disturbance increased in all 3 groups over the course of the study. Measured outcomes relating to mood may be confounded with the timing of the study, which ran during the COVID pandemic. Overall, we demonstrate the role of oral and topical herbs and of nutraceuticals for skin health and wellness. Further research will be needed to elucidate synergistic effects in oral and topical combination regimens.

Melasma is a pathology with multifactorial causes that results in hyperpigmentation of sun-exposed areas, particularly facial skin. New treatments targeting the different factors regulating this condition need to be effective with and have limited adverse effects. Here, we describe a novel combination of two natural compounds (apigenin and phloretin) that has synergistic effects regulating melanogenesis in vitro. Both compounds inhibit Wnt-stimulated melanogenesis and induce autophagy in melanocytes. Apigenin induces DKK1, a Wnt pathway inhibitor, and reduces VEGF, a melanogenesis and proangiogenic factor, in fibroblasts. Moreover, apigenin induces miR-675, a melanogenesis inhibitor miRNA that is reduced in melasma skin in melanocytes. Both compounds showed senomorphic effects by regulating extracellular-matrix-related genes in senescent fibroblasts. Topical application of the compounds also showed significant melanin reduction in a reconstructed human epidermis after 7 days. Thus, the combination of apigenin and phloretin shows promising results as an effective topical treatment of skin hyperpigmentation conditions.