Fast freezing inhibits melanin synthesis of melanocytes by modulating the Wnt/ß-catenin signalling pathway.

Skin hyperpigmentation is mainly caused by excessive synthesis of melanin; however, there is still no safe and effective therapy for its removal. Here, we found that the dermal freezer was able to improve UVB-induced hyperpigmentation of guinea pigs without causing obvious epidermal damage. We also mimic freezing stimulation at the cellular level by rapid freezing and observed that freezing treatments <2.5 min could not decrease cell viability or induce cell apoptosis in B16F10 and Melan-A cells. Critically, melanin content and tyrosinase activity in two cells were greatly reduced after freezing treatments. The dramatic decrease in tyrosinase activity was associated with the downregulation of MITF, TYR, TRP-1 and TRP-2 protein expression in response to freezing treatments for two cells. Furthermore, our results first demonstrated that freezing treatments significantly reduced the levels of p-GSK3ß and ß-catenin and the nuclear accumulation of ß-catenin in B16F10 and Melan-A cells. Together, these data suggest that fast freezing treatments can inhibit melanogenesis-related gene expression in melanocytes by regulating the Wnt/ß-catenin signalling pathway. The inhibition of melanin production eventually contributed to the improvement in skin hyperpigmentation induced by UVB. Therefore, fast freezing treatments may be a new alternative of skin whitening in the clinic in the future.

Postinflammatory Hyperpigmentation Following Mohs Micrographic Surgery: An Observational Study.

IMPORTANCE: Functional and cosmetic outcomes following Mohs micrographic surgery (MMS) are poorly studied in individuals with skin of color (SOC). Postinflammatory hyperpigmentation (PIH) may be long-lasting and highly distressing. SOC individuals are particularly susceptible to PIH following procedures.  Objective: To characterize factors that contribute to the development of PIH following MMS in SOC. DESIGN: This retrospective study included 72 SOC individuals with 83 cases of keratinocyte carcinoma treated with MMS between August 2020 and August 2021 at a single medical center in the Bronx, New York. RESULTS: Postinflammatory hyperpigmentation following Mohs micrographic surgery was more common in Fitzpatrick skin types (FST) IV to V (48.0%) compared to FST I to III (18.2%; P=0.006). Grafts and granulation resulted in higher rates of PIH compared to linear repairs and flaps (87.5% vs 30.7%; P=0.003). Cases with postoperative complications resulted in higher rates of PIH compared to cases without (81.8% vs 29.2%; P=0.001). In a subset analysis of linear repairs, polyglactin 910 as a subcutaneous suture produced a higher rate of PIH compared to poliglecaprone 25 (46.2% vs 7.1%; P=0.015).  Conclusions and Relevance: Individuals with SOC (FST IV to V) are more likely to develop PIH following MMS. Grafts and granulation lead to PIH more often than linear repairs and flaps. Postoperative complications significantly increase the risk of PIH. Surgeons should consider these risk factors during surgical planning in an effort to mitigate PIH in SOC individuals. Studies with larger sample sizes are indicated.  J Drugs Dermatol. 2024;23(5):316-321. doi:10.36849/JDD.8146.

A systematic review of procedural modalities in the treatment of notalgia paresthetica.

BACKGROUND: Notalgia paresthetica (NP) is a rare condition characterized by localized pain and pruritus of the upper back, associated with a distinct area of hyperpigmentation. Given the lack of standardized treatment and the uncertain efficacy of available options, applying procedural methods is of growing interest in treating NP. AIMS: We sought to comprehensively evaluate the role of procedural treatments for NP. METHODS: We systematically searched PubMed/Medline, Ovid Embase, and Web of Science until November 14th, 2023. We also performed a citation search to detect all relevant studies. Original clinical studies published in the English language were included. RESULTS: Out of 243 articles, sixteen studies have reported various procedural modalities, with or without pharmacological components, in treating NP. Pharmacological procedures, including injections of botulinum toxin, lidocaine, and corticosteroids, led to a level of improvement in case reports and case series. However, botulinum toxin did not show acceptable results in a clinical trial. Moreover, non-pharmacological procedures were as follows: physical therapy, exercise therapy, kinesiotherapy, acupuncture and dry needling, electrical muscle stimulation, surgical decompression, and phototherapy. These treatments result in significant symptom control in refractory cases. Physical therapy can be considered a first-line choice or an alternative in refractory cases. CONCLUSION: Procedural modalities are critical in the multidisciplinary approach to NP, especially for patients who are refractory to topical and oral treatments. Procedural modalities include a spectrum of options that can be applied based on the disease's symptoms and severity.

A novel professional-use synergistic peel technology to reduce visible hyperpigmentation on face: Clinical evidence and mechanistic understanding by computational biology and optical biopsy.

Topicals and chemical peels are the standard of care for management of facial hyperpigmentation. However, traditional therapies have come under recent scrutiny, such as topical hydroquinone (HQ) has some regulatory restrictions, and high concentration trichloroacetic acid (TCA) peel pose a risk in patients with skin of colour. The objective of our research was to identify, investigate and elucidate the mechanism of action of a novel TCA- and HQ-free professional-use chemical peel to manage common types of facial hyperpigmentation. Using computational modelling and in vitro assays on tyrosinase, we identified proprietary multi-acid synergistic technology (MAST). After a single application on human skin explants, MAST peel was found to be more effective than a commercial HQ peel in inhibiting melanin (histochemical imaging and gene expression). All participants completed the case study (N = 9) without any adverse events. After administration of the MAST peel by a dermatologist, the scoring and VISIA photography reported improvements in hyperpigmentation, texture and erythema, which could be linked to underlying pathophysiological changes in skin after peeling, visualized by non-invasive optical biopsy of face. Using reflectance confocal microscopy (VivaScope®) and multiphoton tomography (MPTflex™), we observed reduction in melanin, increase in metabolic activity of keratinocytes, and no signs of inflammatory cells after peeling. Subsequent swabbing of the cheek skin found no microbiota dysbiosis resulting from the chemical peel. The strong efficacy with minimum downtime and no adverse events could be linked to the synergistic action of the ingredients in the novel HQ- and TCA-free professional peel technology.

Pycnogenol® prevents skin hyperpigmentation following sclerotherapy.

BACKGROUND: The aim of this registry supplement study was to evaluate the effects of the oral supplement Pycnogenol® on possible skin discolorations or other minor skin changes after varicose vein sclerotherapy in comparison with a standard management (SM). METHODS: One hundred sixty-one subjects completed the study. 84 took Pycnogenol® from the day before sclerotherapy for 12 weeks and followed SM. 77 followed SM only and served as controls. 420 injection sites were followed-up in the Pycnogenol® group and 431 in the control group. The number of injected veins (using only Aetoxysklerol) was on average 4-8 veins/patient. No side effects were observed for the SM or for supplementation. Pycnogenol® supplementation showed a good tolerability. The two management groups were comparable for age, sex and veins distribution at inclusion. RESULTS: After 12 weeks, skin discoloration assessed by a skin staining score was generally significantly lower and less frequent (P<0.05) with Pycnogenol® with a score of 0.4±0.2 compared to controls (with a score of 2.1±0.4). In addition, the number of stains per treated vein was significantly lower in the Pycnogenol® group than the control group. CONCLUSIONS: Varicose vein sclerotherapy is a minimally invasive procedure almost without complications. Pycnogenol® intake appears to improve healing and prevent skin discolorations after injection of the sclerosing agent. To verify this effect of Pycnogenol®, more studies for a longer period are needed.

Relationship of skin complexion with gingival tissue color and hyperpigmentation. A multi-ethnic comparative study.

BACKGROUND AND OBJECTIVE: The most frequently seen intra-oral soft tissue is the gingiva. Most often, it is seen as coral-pink tissue that surrounds the neck of the teeth. Gingiva that encircles the tooth necks and covers the alveolar processes of the jaws is an intra-oral tissue that exhibits biomimetic features. The wide range of colors of the gingiva depends on the configuration of gingival vascularity, the degree of epithelial cornification, level of melanogenesis, and the depth of epithelialization. However, the color of the gingiva varies depending on the degree of melanin pigmentation. The current study aimed to identify the different distribution patterns of gingival color and determine the correlation between skin color, gender, and geographical area of origin. MATERIALS AND METHODS: A total of 839 subjects were involved in the study where the gingival color and skin tone were measured using the Dummett-Gupta Oral pigmentation Index (DOPI) combined with VITA VMK MASTER and skin shade method developed by Revlon (USA) and L'Oreal (France) for makeup foundation shades. One investigator was calibrated for the examination of the colors after being tested for normal color vision and color aptitude using the line test. RESULTS: A significant association was found between skin color and gingival pigmentation (χ2 value (6) = 114.48; P = 0.001). It was also found that females (67.1%) significantly had darker gingiva than males (58.3%). The study statistics display that location of the individual was also statistically associated with melanin pigmentation of the gingiva (χ2 value (57) = 559.33; P = 0.001). CONCLUSION: The study concluded that gender, skin color, and individual location are significantly associated with gingival melanin pigmentation.

A Silymarin Antioxidant Serum Improves Facial Acne Alone and as Part of a Treatment Regimen.

BACKGROUND: Silymarin is an antioxidant that can protect against free radicals that cause premature signs of aging and oil oxidation that may contribute to breakouts. AIMS: The objective of these studies was to evaluate a silymarin antioxidant serum alone and in combination with a prescription acne treatment regimen in improving facial appearance in blemish-prone skin.  Methods: Two international studies were conducted. A 12-week study in Brazil enrolled 56 subjects to examine the effect of silymarin antioxidant serum on facial acne. Clinical grading on acne lesions, skin tone, clarity, and postinflammatory hyperpigmentation (PIH) were conducted. In addition, consumer self-assessment, analysis for markers of lipid peroxidation, and sebumeter analysis were completed. Another Unites States (US)/German study enrolled 40 subjects who were on topical prescription acne medications to which silymarin antioxidant serum was added. Acne lesion counts, tolerability, and facial appearance assessments were conducted in this study. RESULTS: The Brazilian study demonstrated a 45% reduction in inflammatory lesions and a 43% reduction in noninflammatory lesions after 12 weeks of silymarin antioxidant serum use. In addition, sebumeter testing showed a 16% reduction in oiliness at week 1. The US/German study showed the benefits of the serum in persons already on prescription acne therapy by reducing facial erythema by 60%, dryness by 49%, and scaling by 67%. CONCLUSION: Silymarin is shown in clinical testing to have significant benefits in reducing lipid peroxidation, oiliness, and PIH, and in improving key markers of skin aging. Additionally, the serum can be used alone or as an adjunctive treatment in acne therapy to further benefit aging, acne-prone skin. J Drugs Dermatol. 2024;23(4):     doi:10.36849/JDD.8120.

Hydroxychloroquine-induced hyperpigmentation of the skin and bull's-eye maculopathy in rheumatic patients: a case report and literature review.

Hydroxychloroquine (HCQ) is used as a traditional disease-modifying antirheumatic drugs (DMARDs), for the treatment of autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, it can cause serious adverse reactions, including hyperpigmentation of the skin and bull's-eye macular lesions. Here, we present a case of HCQ-induced hyperpigmentation of the skin and bull's-eye macular lesions in a patient who received HCQ for RA. A 65-year-old female patient developed blurred vision and hyperpigmentation of multiple areas of skin over the body for one month after 3 years of HCQ treatment for RA. Based on clinical presentation, ophthalmological examination and dermatopathological biopsy, a diagnosis of drug-induced cutaneous hyperpigmentation and bullous maculopathy of the right eye was made. After discontinuation of HCQ and treatment with iguratimod tablets, the hyperpigmentation of the patient 's skin was gradually reduced, and the symptoms of blurred vision were not significantly improved. We also reviewed the available literature on HCQ-induced cutaneous hyperpigmentation and bull's-eye macular lesions and described the clinical features of HCQ-induced cutaneous hyperpigmentation and bull's-eye macular lesions. In conclusion, clinicians should be aware of early cutaneous symptoms and HCQ-associated ophthalmotoxicity in patients with rheumatic diseases on HCQ sulphate and should actively monitor patients, have them undergo regular ophthalmological examinations and give appropriate treatment to prevent exacerbation of symptoms.

Molecular mechanisms underlying Tao-Hong-Si-Wu decoction treating hyperpigmentation based on network pharmacology, Mendelian randomization analysis, and experimental verification.

CONTEXT: Hyperpigmentation, a common skin condition marked by excessive melanin production, currently has limited effective treatment options. OBJECTIVE: This study explores the effects of Tao-Hong-Si-Wu decoction (THSWD) on hyperpigmentation and to elucidate the underlying mechanisms. MATERIALS AND METHODS: We employed network pharmacology, Mendelian randomization, and molecular docking to identify THSWD's hub targets and mechanisms against hyperpigmentation. The Cell Counting Kit-8 (CCK-8) assay determined suitable THSWD treatment concentrations for PIG1 cells. These cells were exposed to graded concentrations of THSWD-containing serum (2.5%, 5%, 10%, 15%, 20%, 30%, 40%, and 50%) and treated with α-MSH (100 nM) to induce an in vitro hyperpigmentation model. Assessments included melanin content, tyrosinase activity, and Western blotting. RESULTS: ALB, IL6, and MAPK3 emerged as primary targets, while quercetin, apigenin, and luteolin were the core active ingredients. The CCK-8 assay indicated that concentrations between 2.5% and 20% were suitable for PIG1 cells, with a 50% cytotoxicity concentration (CC50) of 32.14%. THSWD treatment significantly reduced melanin content and tyrosinase activity in α-MSH-induced PIG1 cells, along with downregulating MC1R and MITF expression. THSWD increased ALB and p-MAPK3/MAPK3 levels and decreased IL6 expression in the model cells. DISCUSSION AND CONCLUSION: THSWD mitigates hyperpigmentation by targeting ALB, IL6, and MAPK3. This study paves the way for clinical applications of THSWD as a novel treatment for hyperpigmentation and offers new targeted therapeutic strategies.

Intraoral cultural tattooing: Possible forensic utility.

The custom of oral tattooing is mainly performed in Ethiopia and Eritrea, and usually results in blue pigmentation of the maxillary gingiva in dentate individuals. However, its usefulness has not been explored in the forensic literature. The aim of this article is to provide a review of this custom and include an unusual case study involving persistent gingival pigmentation. Herein, this report describes a 43-year-old woman from Eritrea who presented with slight bluish hue of the edentulous maxillary ridge associated with cultural tattooing. Elucidation of the cause of subtle blue hyperpigmentation may be challenging as cultural tattooing typically fades with age. Timely recognition of this oral pseudopathologic process may serve as secondary evidence for forensic identification and possibly provide aid in localizing one's ethnogeographic origin.

Pigmentary Changes in a Woman With Oral Lichen Planus.

A woman in her 60s presented with oral lichen planus on hands and cheeks since childhood and also present in her parent and sibling. What is your diagnosis?

Efficacy and tolerability of a depigmenting gel serum comprising tranexamic acid, niacinamide, 4-butylresorcinol, phytic acid, and a mixture of hydroxy acids that targets the biological processes regulating skin melanogenesis.

BACKGROUND: The diverse causes of hyperpigmentation and complex nature of melanogenesis make it a challenge to manage. Current approaches either fail to deliver effective pigmentation control or have undesirable safety profiles that preclude their long-term use. AIMS: To evaluate the capacity of a cosmetic gel serum comprising tranexamic acid, niacinamide, 4-butylresorcinol, phytic acid, and a mixture of hydroxy acids that was designed to target the biological processes regulating skin melanogenesis to attenuate melanin production in vitro and reduce hyperpigmentation clinically. METHODS: Capacity to reduce melanin production in vitro was determined in melanocyte-containing reconstructed human epidermis (RHEm). Clinical efficacy and skin tolerability following twice daily application were assessed in 35 subjects with slight to moderate facial hyperpigmentation by instrumental (VISIA®-CR, Mexameter®) and clinical (mMASI, clinical score, IGA for hyperpigmentation) evaluation on D14, D28, D56, and D84. Maintenance of pigmentation control was followed up 1 month after cessation of treatment on D112. RESULTS: In RHEm in vitro, melanin production was reduced by 50.0% from baseline (D0) on D14 (p < 0.001) and by 67.0% on D21 (p < 0.001). Clinical reductions from baseline in brown spots count (-9.0%; p < 0.05), brown spots area (-16.7%; p < 0.001), and the melanin index (-11.4%; p < 0.001) were observed within 14 days of use. Statistically significant improvements in all clinical parameters were achieved by D28. By the end of treatment on D84, the number and surface area of brown spots were reduced by 28.4% and 40.3% compared to D0, respectively (p < 0.001, both), the melanin index was reduced by 31.1% (p < 0.001), mMASI was reduced by 63.0% (p < 0.001), and skin luminosity was increased by 79.0% (p < 0.001). IGA was reduced from 2.3 on D0 to 1.3 on D84 (p < 0.001). Improvements to all these parameters were maintained until D112, 1 month after termination of treatment. The product also demonstrated very good skin tolerability. CONCLUSION: A gel serum comprising tranexamic acid, niacinamide, 4-butylresorcinol, and hydroxy acids, designed to target the biological processes regulating skin melanogenesis, demonstrates rapid, robust, and sustained pigmentation control in this cohort.