BACKGROUND: Dark-skinned individuals (DSI) present high rates of melasma and post-inflammatory hyperpigmentation. The use of sunscreens with mineral filters is essential for prevention and treatment. Our objective was to determine the preferences of dermatologists and dermatology residents in the prescription of sunscreens for DSI.
METHODS: An anonymous survey of attendees at an online photoprotection event held on March 31, 2022, in Spain.
RESULTS: The survey was answered by 66.6% (221/332) of the attendees: 159 dermatologists (71.9%) and 62 dermatology residents (28.1%). Respondents reported recommending the use of sunscreen to a median of 80% of DSI [interquartile range (IQR), 50-90]. Physicians reported prescribing tinted sunscreens to a median percentage of 60% (IQR, 25-90) of DSI with acne; and to a median percentage of 90% (IQR, 58-99) of DSI with melasma. The most prescribed photoprotectors to DSI with melasma were organic broad-spectrum sunscreens with antioxidants: 102/220 (46.4%) and mineral broad-spectrum sunscreens (with iron oxides): 45/220 (20.4%). In DSI with melasma or other pigmentary disorders, the most preferred features of sunscreens were as follows: sun protection factor ≥ 30: 217/221 (98.2%), UVA protection: 214/221 (96.8%), color for camouflage: 150/220 (68.2%) and mineral filters such as titanium dioxide and zinc oxide: 151/220 (68.6%) or iron oxides: 131/220 (59.5%).
CONCLUSIONS: Online survey, potential inclusion bias.
CONCLUSIONS: Respondents reported to prescribe sunscreens to the majority of DSI, and tinted sunscreens for the majority of DSI with pigmentary disorders. However, the most frequently recommended sunscreens for DSI were organic broad-spectrum sunscreens with antioxidants.

BACKGROUND: Methimazole, an oral antithyroid drug, has recently gained attention for its skin-brightening effects when applied topically to treat melasma. This study aims to develop, optimize, and characterize a methimazole microemulsion as a novel, safe approach for local melasma treatment.
METHODS: We prepared microemulsion formulations containing 3% methimazole by combining appropriate amounts of surfactants (Tween 80 and Span 20), propylene glycol cosurfactant, and an oil phase (oleic acid-transcutol p at a 1:10 ratio). We then assessed droplet size, stability, viscosity, and skin permeation using rat skin models.
RESULTS: The microemulsions\' droplet sizes ranged from 7.06 to 28.13 nm, with viscosities between 120 and 254 centipoises. Our analysis identified droplet size, viscosity, and membrane release as significant independent variables. We determined the permeability parameters of the optimal formulation through rat skin, including steady-state permeability rate (Jss), permeability coefficient (p), lag time (Tlag), and apparent diffusion coefficient (Dapp).
CONCLUSIONS: We found that the microemulsions\' characteristics, physicochemical properties, and in vitro release depended on the surfactant-to-cosurfactant ratio, water content, and oil content. We developed an optimal formulation with a high surfactant-to-cosurfactant ratio and low water and oil percentages. This formulation shows potential for commercialization and manufacturing of final products.

暂无摘要。

Melasma, a prevalent pigmentary disorder, is characterized by its complex etiology, propensity for recurrence, and resistance to treatment. However, there is currently no research on melasma through bibliometrics and visualisation. This study analyses the hotspots and trends in the field based on 2,709 publications from the Web of Science Core Collection (WOSCC). We carried out bibliometric analyses using Citespace software for different countries/regions, institutions, authors, and keywords. References were also analysed using VoSviewer. The results indicate that overall, there has been an increase in publications related to melasma since 2014. According to the analysis of the collaborative network diagram, the United States, Egyptian Knowledge Bank, and Benjakul Soottawat are the most contributing countries, institutions, and authors, respectively. Reference and keyword analyses have identified the pathogenesis and treatment of melasma as a prevalent topic in recent years. And how to find new treatment options and more effective therapeutic drugs is a future research trend. This is the first bibliometric and visual analysis of melasma-related literature to explore research hotspots and trends.

Tyrosinases (TYRs) are copper-containing metalloenzymes present in a large diversity of species. In human, hTYR is responsible for pivotal steps in melanogenesis, catalysing the oxidation of l-tyrosine to l-DOPA and further to dopaquinone. While numerous TYR inhibitors have been reported, polyphenolic compounds tend to dominate the literature. However, many of these compounds, particularly monophenols and catechols, have been identified as alternative substrates rather than true inhibitors, given their structural similarity to natural substrates. Resorcinol-containing compounds have emerged as promising candidates to address this challenge, as the meta-dihydroxy moiety in resorcinol demonstrates resistance to TYR-mediated oxidation, while retaining the favourable interactions with copper ions provided by the hydroxy groups. Although their precise mechanism of action remains debated, resorcinol derivatives have yielded some of the most active compounds against isolated mushroom and human TYRs, as well as clinically used dermocosmetic agents like rucinol and thiamidol, which exhibited very promising effects in patients with facial melasma. This review outlines the development of resorcinol-containing TYR inhibitors, categorized by scaffold type, ranging from simple alkyl analogues to intricate synthetic derivatives. Mechanistic insights about the resorcinol-TYR interaction are also presented and debated.

Melasma is a prevalent dermatological challenge with limited therapeutic interventions. Platelet-rich plasma (PRP) has been increasingly explored for its potential benefits in various dermatological conditions. This study aimed to systematically review the efficacy and safety of PRP in the treatment of melasma. A comprehensive search in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was executed in January 2024 using PubMed, focusing on studies investigating the efficacy and safety of PRP in melasma. Criteria for inclusion were clinical trials and controlled studies examining PRP\'s role in melasma treatment, while exclusions covered reviews, non-English articles, and studies older than 10 years, among others. Eight studies were included, with the majority targeting female participants. The research displayed consistent positive outcomes, whether PRP was used alone or synergistically with treatments like hydroquinone and tranexamic acid. However, positive studies with the combination of PRP and other drugs will not provide the actual safety and efficacy data of PRP. The combined treatment approaches often showed enhanced results. Satisfaction rates among patients and reductions in the melasma area and severity index (MASI) scores were common findings across the studies, emphasizing the potential of PRP in melasma management. In conclusion, PRP emerges as a promising therapeutic intervention for melasma. Whether as a standalone treatment or combined with established methods, PRP presents significant potential in melasma\'s clinical management, warranting further expansive trials to substantiate its long-term efficacy and safety.

BACKGROUND: The severity and treatment response of acne, melasma, and rosacea may be influenced by various currently unclear internal and external factors. This study aimed to provide evidence to the influencing factors for the mentioned conditions through a real-world case-control study.
METHODS: An online survey consisting of 60 questions was implemented, collecting information on demographics, socioeconomics, genetic factors, lifestyle habits, environmental exposures, and skin care behaviors. Then we constructed univariate and multivariate logistic regressions. Furthermore, we analyzed the dose-response relationship between exposure and outcome.
RESULTS: A total of 399 individuals, including 94 acne patients, 107 melasma patients, and 91 rosacea patients were included. Acne and melasma were positively correlated with screen time (acne: odds ratio [OR]: 2.24, 95% confidence interval [CI]: 1.25-4.02; melasma: OR: 1.59, 95% CI: 1.09-2.31), while exercise exerted a protective effect on both acne (OR: 0.31, 95% CI: 0.13-0.77) and melasma (OR: 0.42, 95% CI: 0.22-0.80) in a dose-response relationship. In addition, males were associated with an elevated risk of acne (OR: 6.62, 95% CI: 1.01-43.26). Aging (OR: 1.15, 95% CI: 1.07-1.24) and irregular bowel movements (OR: 2.99, 95% CI: 1.11-8.08) were independent risk factors for melasma. Rosacea was positively associated with BMI (OR: 1.17, 95% CI: 1.01-1.35).
CONCLUSIONS: In our study, we highlighted exercise as an independent protective factor for both acne and melasma in a dose-response trend. Inversely, extended use of electronic equipment was independently associated with higher risks of acne and melasma. Rosacea, however, was more likely to be related with BMI.

UNASSIGNED: Response to the current available treatments of melasma, dermal type, in particular, is usually gradual and can result in possible side effects.
UNASSIGNED: In this study, we aim to evaluate the efficacy of the combination of plasma rich in growth factors (PRGF) and topical 4% hydroquinone (HQ) in comparison with monotherapy using topical 4% HQ alone in the treatment of dermal type of melasma.
UNASSIGNED: This is a single-blinded, randomized, split-face clinical trial on twenty female patients with dermal type of melasma. Patients were asked to apply topical 4% HQ on both sides of their face at night for 6 months. In each participant, one side of the face was randomly chosen to receive monthly intradermal injections of PRGF for 3 sessions. Efficacy of the treatment was assessed using hemi melasma area and severity index (MASI) score, physician\'s global assessment (PGA), and patients\' global assessment (PtGA).
UNASSIGNED: Both groups revealed significant improvement in hemi-MASI score during the treatment course. Mean percentage of improvement at the end of study was 40.38 ± 6.04% and 33.42 ± 3.23% in the combination therapy and monotherapy groups, respectively (P = 0.31). PGA demonstrated excellent-to-marked improvement in melasma in 25% and 5% of patients in the combination therapy and monotherapy groups, respectively (P = 0.31). PtGA showed high levels of satisfaction in 15% of patients in the combination therapy group (vs. 0% in the monotherapy group) (P = 0.05).
UNASSIGNED: Differences between the two treatment groups in terms of hemi-MASI and PGA scores were not statistically significant; however, patients demonstrated higher satisfaction with combination of PRGF and topical 4% HQ compared with topical HQ alone. Thereby, combination of PRGF and topical 4% HQ can be suggested as a safe alternative therapeutic approach and may hold promise in the development of future therapeutic options for dermal type of melasma.

BACKGROUND: The challenging management of melasma highlights the inadequacies of conventional therapies and their high risk of recurrence. Integrating microneedling for device-assisted drug delivery with tranexamic acid (TA), recognized for its melanin synthesis inhibition, presents a novel approach that warrants further investigation to fully assess its potential in enhancing melasma treatment efficacy.
METHODS: Fifty moderate to severe melasma patients participated in this randomized outcome-assessor-blinded controlled trial. Patients were randomly allocated into two main groups. Group A received a modified Kligman formula on one hemi-face on alternate nights for 2 months (A1) and three sessions of microneedling with 10% topical TA on the other hemi-face at 1-month intervals (A2). Group B used the same modified Kligman formula on both sides of the face, with one side additionally receiving three sessions of microneedling with 4% TA (B1) and the opposite side with 10% TA (B2). Primary outcomes were % Modified Melasma Area and Severity Index (mMASI) and % visual analogue scale (VAS) change during 6 month follow-up. Adverse events including post-inflammatory hyperpigmentation (PIH) and treatment tolerability were recorded.
RESULTS: Compared to baseline, the mean mMASI reduction immediately after the final session was higher in A1, B1, and B2 (56.84%, 50.88%, and 55.87%, respectively) than in A2, which saw only a 13.16% reduction. Efficacy notably declined after the cessation of treatment across all groups. While the efficacy within groups A1, B1, and B2 was comparable, microneedling with 4% or 10% TA combined with the topical modified Kligman formula proved more potent in patients at a lower risk of PIH. Overall, 22% of patients reported PIH, particularly in the A2 group (28% of hemi-faces), with its occurrence significantly associated with treatment during warmer seasons and in darker skin phototypes. Other adverse events were not observed in any patient. Patient satisfaction was highest in groups B1 and B2, where approximately 72% reported \'excellent\' satisfaction. The lowest durability rate (16%) was observed in group A2, while the highest (72%) was seen in group B2, comparable with groups A1 and B1. Treatment tolerability was reported 100% in all groups.
CONCLUSIONS: It was found that the modified Kligman formula outperformed microneedling-TA alone. However, with optimal patient selection, particularly targeting those at lower risk for PIH with lighter skin phototypes and scheduling treatments during less-sunny seasons, combining microneedling with 4% or 10% TA and the modified Kligman formula significantly enhanced efficacy and satisfaction rates compared to conventional topical treatment.

Pigmentary and hair disorders have a significant cosmetic and psychological impact. In the August issue of the Journal, we highlight the use of reflectance confocal microscopy in diagnosing and monitoring treatment responses in patients with melasma. We will also discuss new therapeutic approaches involving oral melatonin and a combination of glutathione and resveratrol for melasma. Additionally, the ongoing revolution in alopecia treatment with oral low-dose minoxidil will be spotlighted, including the circumstances under which media attention has contributed to the growing interest in oral minoxidil prescriptions.