Dermal Pathology in Melasma: An Update Review

Research situation, hot spots, and global trends of melasma therapy: Bibliometric insights and visual analysis from 2000 to 2023

BACKGROUND

Melasma is a prevalent pigmented disease, yet its pathogenesis remains unclear, posing challenges for effective treatment. Bibliometric analysis, a novel approach to literature research, offers the opportunity to evaluate research trends through qualitative and quantitative methods. This study utilizes bibliometric methods to analyze the existing literature on melasma treatment, examining influential publications, institutions, countries, and authors through statistical analysis.

METHODS

In order to retrieve manuscripts related to the topic of melasma treatment, we conducted a search using the search formula: (TS = (melasma or Chloasma or "mask of pregnancy")) AND TS = (treatment or therapy). We searched through the Web of Science Core Collection database, covering publications from 2000 to 2023. VOSviewer, CiteSpace and the Bibliometric online site (https://bibliometric.com/app) were used to conduct this bibliometric analysis. Our analysis focused on various factors including publications, authors co-authorship, institutions, countries, citation analysis, keywords co-occurrence, references co-citation and journal co-citation.

RESULTS

A total of 943 articles and 200 reviews were published between 2000 and 2023, accumulating a total of 8628 citations. The average number of citations per item was 18.85, and the average number of citations per year was 292.69. The most prolific author, Sungeun Chang, contributed a total of 9 articles. Cario University emerged as the top research institution. The United States led in terms of article publications with a count of 276. In the past 5 years, the research trends in this field have primarily focused on tranexamic acid and epidermal melasma, as indicated by the burst analysis of publications and keywords.

CONCLUSIONS

The United States continues to lead in terms of institutions and research output. The current emphasis is on the meticulous implementation of tranexamic acid and laser therapy. It is crucial to foster enhanced collaboration among countries, institutions, and authors to facilitate improved research.

Update on Melasma Treatments

Melasma is a prevalent hyperpigmentation condition known for its challenging treatment due to its resemblance to photoaged skin disorders. Numerous studies have shed light on the intricate nature of melasma, which often bears similarity to photoaging disorders. Various therapeutic approaches, encompassing topical and systemic treatments, chemical peeling, and laser therapy, have exhibited efficacy in managing melasma in previous research. However, melasma often reoccurs despite successful treatment, primarily due to its inherent photoaged properties. Given that melasma shares features with photoaging disorders, including disruptions in the basement membrane, solar elastosis, angiogenesis, and mast cell infiltration in the dermal layer, a comprehensive treatment strategy is imperative. Such an approach might involve addressing epidermal hyperpigmentation while concurrently restoring dermal components. In this article, we provide a comprehensive review of conventional treatment methods frequently employed in clinical practice, as well as innovative treatments currently under development for melasma management. Additionally, we offer an extensive overview of the pathogenesis of melasma.

Tranexamic Acid Ameliorates Skin Hyperpigmentation by Downregulating Endothelin-1 Expression in Dermal Microvascular Endothelial Cells

BACKGROUND

Although reports suggest that tranexamic acid (TXA) has clinical benefits for melasma patients by oral, intralesional and topical treatment, the optimal route of TXA therapy and the underlying mechanism involved remain poorly defined.

OBJECTIVE

To compare the skin lightening effect between oral TXA and topical TXA and to dissect the molecular mechanisms using ultraviolet B (UVB)-induced hyperpigmentation mouse model, ex vivo cultured human skin explant, and cultured melanocytes (MCs) and endothelial cells.

METHODS

Melanin content and cluster of differentiation 31 (CD31)-positive cell numbers were measured in tail skins from UVB-irradiated mice treated by intragastral or topical TXA using immunofluorescent and Fontana-Masson staining. The conditioned medium (CM) was harvested from human umbilical vein endothelial cells treated with or without 3 mM TXA and was used to treat MCs for 48 hours. mRNA and protein levels of tyrosinase and microphthalmia-associated transcription factor were measured using quantitative real-time reverse transcription polymerase chain reaction and western blotting assays. HMB45- and CD31-positive cell numbers as well as melanin content were also examined in ex vivo cultured human skin explants.

RESULTS

The hyperpigmented phenotype were significantly mitigated in UVB-irradiated tail skin plus intragastral TXA-treated mice compared with mice treated with UVB only or with UVB plus topical TXA. CD31-positive cell numbers correlated with the anti-melanogenic activity of TXA therapy. The data from cultured cells and skin tissues showed that suppression of endothelin-1 (ET-1) in vascular endothelial cells by TXA reduced melanogenesis and MC proliferation.

CONCLUSION

Oral TXA outperforms topical TXA treatment in skin lightening, which contributes to suppression of ET-1 in dermal microvascular endothelial cells by TXA.

Exposure factors in the occurrence and development of melasma (Review)

Melasma is an acquired pigmentation disease that mainly involves the development of symmetrical yellow-brown facial patches. The incidence rate of the disease is increasing yearly. Therefore, actively studying the exposure factors that induce melasma could contribute to the prevention and treatment of this disease. In the present review, the possible exposure factors were summarized.

Co-Treatment with Phlorotannin and Extracellular Vesicles from Ecklonia cava Inhibits UV-Induced Melanogenesis

Hyperpigmentation due to ultraviolet (UV)-induced melanogenesis causes various esthetic problems. Phlorotannin (PT) and extracellular vesicles (EVs) derived from various plants suppress melanogenesis pathways. We used UV-exposed keratinocytes and animal skin to determine if co-treatment with PT and EVs from Ecklonia cava (EVE) could inhibit melanogenesis by reducing UV-induced oxidative stress and the expression of the thioredoxin-interacting protein (TXNIP)/nucleotide-binding oligomerization domain-like receptor family pyrin domain containing the 3 (NLRP3)/interleukin-18 (IL-18) pathway, which are upstream signals of the microphthalmia-associated transcription factor. UV exposure increased oxidative stress in keratinocytes and animal skin, as evaluated by 8-OHdG expression, and this effect was reduced by co-treatment with PT and EVE. UV also increased binding between NLRP3 and TXNIP, which increased NLRP3 inflammasome activation and IL-18 secretion, and this effect was reduced by co-treatment with PT and EVE in keratinocytes and animal skin. In melanocytes, conditioned media (CM) from UV-exposed keratinocytes increased the expression of melanogenesis-related pathways; however, these effects were reduced with CM from UV-exposed keratinocytes treated with PT and EVE. Similarly, PT and EVE treatment reduced melanogenesis-related signals, melanin content, and increased basement membrane (BM) components in UV-exposed animal skin. Thus, co-treatment with PT and EVE reduced melanogenesis and restored the BM structure by reducing oxidative stress and TXNIP/NLRP3/IL-18 pathway expression.

Photobiomodulation for melasma treatment: Integrative review and state of the art

PURPOSE

Photobiomodulation therapy (PBM) is a versatile technique for treating skin diseases. Melasma, a chronic hyperpigmentation condition, has recently been associated with vascular features and dermal photoaging and poses significant management challenges. We review the recent literature on melasma etiology and the evidence supporting PBM as a therapeutic modality for melasma treatment.

METHODS

We conducted a comprehensive literature search in three different databases from May to August 2023, focusing on studies published in the past 10 years. The inclusion criteria comprised full-text studies investigating low-power lasers and/or light-emitting diodes (LEDs) in in vitro or in vivo models, as well as clinical trials. We excluded studies discussing alternative melasma therapies or lacking experimental data. We identified additional studies by searching the reference lists of the selected articles.

RESULTS

We identified nine relevant studies. Clinical studies, in agreement with in vitro experiments and animal models, suggest that PBM effectively reduces melasma-associated hyperpigmentation. Specific wavelengths (red: 630 nm; amber: 585 and 590 nm; infrared: 830 and 850 nm) at radiant exposures between 1 and 20 J/cm2 exert modulatory effects on tyrosinase activity, gene expression, and protein synthesis of melanocytic pathway components, and thus significantly reduce the melanin content. Additionally, PBM is effective in improving the dermal structure and reducing erythema and neovascularization, features recently identified as pathological components of melasma.

CONCLUSION

PBM emerges as a promising, contemporary, and non-invasive procedure for treating melasma. Beyond its role in inhibiting melanogenesis, PBM shows potential in reducing erythema and vascularization and improving dermal conditions. However, robust and well-designed clinical trials are needed to determine optimal light parameters and to evaluate the effects of PBM on melasma thoroughly.

Clinical Development and Evaluation of a Multi-Component Dissolving Microneedle Patch for Skin Pigmentation Disorders

Excessive melanin deposition in the skin leads to various skin pigmentation diseases, such as chloasma and age spots. The deposition is induced by several factors, including tyrosinase activities and ultraviolet-induced oxidative stress. Herein, we propose a multi-component, multi-pathway drug combination, with glabridin, 3-O-ethyl-L-ascorbic acid, and tranexamic acid employed as, respectively, a tyrosinase inhibitor, an antioxidant, and a melanin transmission inhibitor. Considering the poor skin permeability associated with topical application, dissolving microneedles (MNs) prepared with hyaluronic acid/poly(vinyl alcohol)/poly(vinylpyrrolidone) were developed to load the drug combination. The drug-loaded microneedles (DMNs) presented outstanding skin insertion, dissolution, and drug delivery properties. In vitro experiments confirmed that DMNs loaded with active ingredients had significant antioxidant and inhibitory effects on tyrosinase activity. Furthermore, the production of melanin both in melanoma cells (B16-F10) and in zebrafish was directly reduced after using DMNs. Clinical studies demonstrated the DMNs' safety and showed that they have the ability to effectively reduce chloasma and age spots. This study indicated that a complex DMN based on a multifunctional combination is a valuable depigmentation product worthy of clinical application.

Self-Esteem, Depression, Anxiety and Quality of Life in Patients with Melasma Living in a Sunny Mediterranean Area: Results from a Prospective Cross-Sectional Study

INTRODUCTION

Melasma is a common acquired disorder of hyperpigmentation and has a significant effect on quality of life. The aim of this prospective cross-sectional study was to assess the effect of melasma on depression, social anxiety and self-esteem in the Greek population.

METHODS

The study included a total of 254 participants: 127 patients with melasma and an equal sample of healthy controls. Both participant groups completed the following psychometric measures: the Hospital Anxiety and Depression Scale (HADS) to assess anxiety and depression and Rosenberg's Self-esteem Scale (RSES) for self-esteem. Furthermore, in patients with melasma, quality of life was assessed using Melasma Quality of Life (MELASQoL).

RESULTS

Melasma patients (7.47 ± 4.53) presented statistically significantly higher anxiety compared to healthy controls (6.06 ± 3.59, p = 0.006), while no differences emerged with regard to depression or self-esteem. It is important to note that the difference regarding anxiety remained significant (b = 1.25, p = 0.003) even after adjusting for age, depression and self-esteem. A higher disease severity (MASI) correlated statistically significantly with longer disease duration (r = 0.24, p < 0.001), higher depression (r = 0.28, p = 0.002), and a more impaired health-related quality of life (MelasQol; r = 0.29, p < 0.001). Notably, a more impaired health-related quality of life was also correlated with higher depression (r = 0.19, p = 0.027) and lower self-esteem (r = - 0.31, p < 0.001).

CONCLUSION

The results of this study highlight the importance of evaluating quality of life, anxiety and depression in patients with melasma. The therapeutic approach should not be based solely on clinical findings; it should also include an evaluation of the patient's psychological aspects. Dermatologists can further improve their patient care by being supportive or requesting psychological intervention when needed, resulting in better compliance with treatment and an improved social and psychological status.

Safety and efficacy of superficial micro-focused ultrasound with visualization for melasma in Asians: An uncontrolled pilot study

BACKGROUND

The pathophysiology of melasma is multifactorial, resulting in treatment resistance and a high recurrence rate. Recent research suggests that focused ultrasound might treat melasma effectively.

OBJECTIVES

To investigate the efficacy and safety of superficial micro-focused ultrasound with visualization (MFU-V) for melasma in Asians.

METHODS

Patients (n = 20) with mixed melasma on both cheeks received 2 MFU-V treatments spaced 1 month apart. At monthly visits over 5 months, treatment efficacy and safety were evaluated. Standardized photographs were clinically assessed using the modified Melasma Area and Severity Index (mMASI), and 6-point grading scales for melasma lightening and area of involvement. Patients provided pain, global aesthetic improvement scale (GAIS), and satisfaction assessments.

RESULTS

In 40 cheeks, the mean mMASI score was significantly reduced from 13.2 at baseline to 2.4 at month 4, and 2.8 at month 5. Twenty-nine cheeks (72.5%) showed lightening of melasma at month 4 that persisted until month 5, with improvements up to 75% compared to baseline. Melasma area decreased overall, with sites containing >30% melasma involvement decreasing from 55% to 20% by month 5, and none with 70%-89% involvement. Melasma lightening and area improved visibly in 40% and 20% of cheeks, respectively, as early as 1 month after index MFU-V treatment. Improvements continued after the second treatment and persisted until study closure, correlating with patient GAIS and satisfaction scores. Procedure was well tolerated with only mild-to-moderate pain reported in 92.5% of treatments.

CONCLUSION

Superficial MFU-V is a safe and effective treatment for melasma.