Postinflammatory Hyperpigmentation: Epidemiology, Clinical Presentation, Pathogenesis and Treatment

A randomised investigation of film-forming silicone gel in superficial partial thickness face and neck burn patients: Indication of improved early scar pigmentation outcomes

INTRODUCTION

Burns to the face and neck are a source of considerable distress and a challenge to manage with dressings. Further, these often superficial injuries pose a risk of scarring and altered pigmentation. Silicone gels have emerged as a potential solution to the challenges of conservative management for face and neck burn injuries. The aims of this study were to explore the effect of topical silicone compared to routine treatment of conservatively managed burns to the face and neck.

METHODS

This single-blind, randomised, controlled trial compared topical silicone film-forming dressing to standard of care for superficial partial thickness burns to the face and neck. Time to healing was the primary outcome and secondary outcomes included: 1) scar assessments (modified Vancouver Scar Scale, Dermalab Combo and Patient and Observer Scar Assessment Scale) at six weeks and three months; and 2) pain intensity scale at wound review appointments.

RESULTS

Of the 55 participants in the face/neck study, 34 were male and 21 were female. Median age was 36 years (range from 25 to 47 years). The median time to healing for the silicone group was 9 days (CI 7.6 -10.4) and the control group was 7 days (CI 5.3- 8.7), p = 0.056. Analysis demonstrated significantly reduced pigmentation at six weeks in mVSS scores for the silicone group (Md = 0, IQR = 0) compared to the control group (Md = 0, IQR = 0 - 3), p = 0.043. We found no evidence of differences in reported pain between the groups (Silicone - Md = 1.15, IQR 0.3 - 4.5 vs control group - Md = 1.5, IQR 0.6 - 3.8, z = -0.63, p = 0.53). No other differences were observed, and no adverse events were associated with the topical silicone in the study whereas an infection and a reaction were experienced in the control group.

CONCLUSION

Film-forming silicone gel had comparable effects to standard of care emollient on wound healing of superficial partial thickness burns of the face and neck. Silicone treated wounds were associated with a significant improvement in scar pigmentation outcome at six weeks post-burn.

Combined multilevel anti-aging strategies and practical applications of dermocosmetics in aesthetic procedures

Management of the signs of facial aging and other cosmetic skin problems have greatly evolved in the past years. People are also seeking to improve their well-being and global skin appearance, and when they consider using cosmetic procedures, they expect natural and long-lasting aesthetic results. Combined dermocosmetic approaches that address the signs of facial aging at all levels are increasingly being used by dermatologists to meet patient expectations while ensuring their safety. Minimally invasive and reversible procedures that can be performed in only one session are popular approaches for skin restructuring and volumizing as they are flexible, rapid and less burdensome for patients. These interventions can achieve even better outcomes when they are combined with cosmeceuticals as pre- or post-procedural adjuvants to prepare the skin, accelerate recovery and sustain results. The use of topical dermocosmetics is also recommended as part of the daily skin care routine to improve skin quality and help maintain skin barrier function. This review thus outlines the most commonly used combined multilevel anti-aging strategies, which start by addressing the deepest skin layers and then the more superficial signs of skin aging. Examples of multi-active cosmeceuticals and skin delivery enhancing systems are also presented, together with examples of the use of dermocosmetics as supportive care for aesthetic procedures, to provide insights into current applications of dermocosmetic products.

Understanding the perception of sunscreen utility in African Americans

Dyschromia is a top diagnosis among African Americans (AA). Sunscreen is an essential part of its management, but AA have low sunscreen use. We sought to examine the perception of sunscreen utility in dyschromia and photoaging among patients who identify as AA or Black. This cross-sectional study recruited participants from the Case Western Reserve University Academic Dental Clinic. Participants completed an electronic survey that contained questions related to sunscreen use, knowledge of the sun's role in hyperpigmentation and photoaging, and whether sunscreen could be used for hyperpigmentation and photoaging. Of the 151 participants recruited, 63.6% (n = 96) were women and 36.4% (n = 57) were men. Consistent with previous reports, participants had lower sunscreen use (20.5%) than whites (43.5%). The majority of participants (80.1% and 58.3%, respectively) didn't attribute the sun to hyperpigmentation or photoaging. Participants with dark/brown spots were significantly more likely to not attribute the sun to hyperpigmentation than those without spots. (p = 0.003) Limitations for this study include its small sample size, recall and reporter bias, question misinterpretation, and lack of question neutrality. This study highlights the knowledge gap of a major contributing factor to dyschromia which in turn could be leading to their view of the decreased utility of sunscreen.

Low-concentration imiquimod treatment promotes enhanced skin barrier functions through epidermal melanization reaction regulation

The primary function of the skin is to form a mechanical, permeability, antimicrobial, and ultraviolet radiation barrier, which is essential for maintaining physiological homeostasis. Our previous studies demonstrated that cutaneous pigmentation could promote skin barrier function in addition to providing anti-ultraviolet irradiation defense. The present study aimed to develop a new regimen that enhances skin barrier function by regulating skin pigmentation using low-concentration imiquimod. Results showed that topical application of low-concentration imiquimod effectively induced skin hyperpigmentation in the dorsal skin and external ear of mice without inducing inflammatory cell infiltration. An in vitro study also revealed that low-concentration imiquimod did not induce any cytotoxic effects on melanoma cells but triggered excessive melanin synthesis. In coculture systems, low-concentration imiquimod was noted to increase tyrosinase activity in a broader cellular context, revealing the potential role of neighboring cells in melanin production. The next-generation sequencing result indicated that PKCη and Dnm3 might regulate melanin synthesis and release during imiquimod treatment. Overall, our study presents new insights into the regulation of melanin production by low-concentration imiquimod, both in a mice model and cultured cells. Furthermore, our study highlights the potential benefits of imiquimod in promoting melanin synthesis without causing skin disruptions or inducing inflammation, validating its potential to serve as a method for enhancing skin barrier functions by regulating the epidermal melanization reaction.

Reducing Carbon Dioxide Laser-Induced Postinflammatory Hyperpigmentation with Prophylactic Photobiomodulation: A Case Study

Objective: This study aimed to investigate the effectiveness of prophylactic photobiomodulation (PBM) in reducing postinflammatory hyperpigmentation (PIH) induced by carbon dioxide (CO2) laser resurfacing in a patient with periorbital syringomas. Background: PIH is a common condition characterized by abnormal skin pigmentation after an inflammatory process occurring in up to 20-30% of patients undergoing CO2 laser resurfacing. Methods: The patient was treated with PBM using a pulsed home-use device at 630 nm before and after CO2 laser treatment. The patient was asked to treat the right periorbital area before and after the CO2 laser treatment, which was continued once a day for 2 consecutive weeks. Results: At 12 weeks, PIH was significantly reduced on the treated side compared with the contralateral untreated side (leading to persistent erythema at 6 months). Conclusions: This is the first report of prophylactic treatment of CO2 laser-induced dyschromia using PBM.

Transient Postinflammatory Hyperpigmentation Following Eyelid Surgery

PURPOSE

The authors' aim was to describe a rare mild complication of eyelid surgery presenting as transient hyperpigmentation along the suture lines.

METHODS

A retrospective case series of 6 patients experiencing transient hyperpigmentation following eyelid surgery. Each patient underwent either blepharoplasty alone or blepharoplasty with ptosis repair utilizing Müller muscle conjunctival resection. Data including surgery type, hyperpigmentation laterality and location, time to diagnosis, follow-up time, and outcome were assessed.

RESULTS

All 6 patients with hyperpigmentation were females. All patients underwent blepharoplasty, including 1 upper eyelid blepharoplasty and 4 with both upper and lower eyelid blepharoplasty. One patient underwent bilateral upper blepharoplasty with concurrent posterior approach ptosis surgery repair of the left upper eyelid. Hyperpigmentation was bilateral in all 5 blepharoplasty cases and unilateral in the ptosis repair case. Hyperpigmentation included the medial portion of the operated upper eyelid in all cases. Time to diagnosis ranged from 1 to 4 weeks postoperatively, and follow-up time ranged from 3 to 5 months. Management was conservative in all cases. Five patients experienced complete resolution, and 1 patient experienced near-complete resolution on a 3-month follow-up.

CONCLUSIONS

Transient hyperpigmentation is a rare posteyelid surgery complication, generally with an excellent outcome not requiring additional intervention.

Melanin Biopolymers in Pharmacology and Medicine-Skin Pigmentation Disorders, Implications for Drug Action, Adverse Effects and Therapy

Melanins are biopolymeric pigments formed by a multi-step oxidation process of tyrosine in highly specialized cells called melanocytes. Melanin pigments are mainly found in the skin, iris, hair follicles, and inner ear. The photoprotective properties of melanin biopolymers have been linked to their perinuclear localization to protect DNA, but their ability to scavenge metal ions and antioxidant properties has also been noted. Interactions between drugs and melanins are of clinical relevance. The formation of drug-melanin complexes can affect both the efficacy of pharmacotherapy and the occurrence of adverse effects such as phototoxic reactions and discoloration. Because the amount and type of melanin synthesized in the body is subject to multifactorial regulation-determined by both internal factors such as genetic predisposition, inflammation, and hormonal balance and external factors such as contact with allergens or exposure to UV radiation-different effects on the melanogenesis process can be observed. These factors can directly influence skin pigmentation disorders, resulting in hypopigmentation or hyperpigmentation of a genetic or acquired nature. In this review, we will present information on melanocyte biology, melanogenesis, and the multifactorial influence of melanin on pharmacological parameters during pharmacotherapy. In addition, the types of skin color disorders, with special emphasis on the process of their development, symptoms, and methods of treatment, are presented in this article.

Pediatric Dermatology for People of Color

When evaluating pediatric patients of color, it is essential to consider the unique diagnostic and treatment factors that apply to this population. Certain dermatologic conditions are more common in these patients, including postinflammatory hyperpigmentation, pityriasis alba, progressive macular hypomelanosis, tinea capitis, traction alopecia, keloids, hypertrophic scars, pseudofolliculitis barbae, acne keloidalis nuchae, and hidradenitis suppurativa. Furthermore, conditions such as vitiligo are more noticeable in people of color. This can lead to a significantly diminished quality of life, so these conditions should be quickly recognized and treated. Notably, inflammation can be difficult to recognize on the skin of people of color, which can lead to the underestimation of severity as well as inappropriate treatment. Treatment recommendations can also differ based on lifestyle or cultural norms, such as the use of tinted sunscreens and the consideration of hair care practices. Pediatricians should be aware of these conditions and treatment considerations to best treat pediatric patients of color. [Pediatr Ann. 2024;53(4):e146-e151.].

Efficacy and Safety of Ablative Fractional Laser in Melasma: A Meta-analysis and Systematic Review

Melasma is a common acquired skin pigmentation disorder. The treatment is urgent but challenging. Ablative fractional laser (AFL) can improve pigmentation, but the efficacy and potential side effects are still debatable. This study aimed to evaluate the efficacy and safety of ablative fractional lasers in the treatment of melasma. A comprehensive systematic search of literature published before June 20, 2023, was conducted on online databases, including PubMed, Embase, Cochrane Library, and Web of Science. The data obtained were analyzed using Review Manager 5.4 software. Fourteen randomized controlled trials, comprising 527 patients, were included. Compared to the drug alone, the combination of AFL and the drug showed improved therapeutic efficacy in the melasma area and severity index (MASI) (MD = 1.54, 95% CI [0.16, 2.92], P = 0.03) and physician global assessment (RR = 1.61, 95% CI [1.08, 2.41], P = 0.02). However, no statistically significant results were found in patient self-assessment (RR = 1.56, 95% CI [0.88, 2.76], P = 0.12). As an individual therapy, AFL is not superior to any other lasers in terms of MASI (MD = 2.66, 95% CI [-1.32, 6.64], P = 0.19) or melanin index (MD = -7.06, 95% CI [-45.09, 30.97], P = 0.72). Common adverse events included transient erythema, burning, edema, and superficial crusting. Only a few patients experienced reversible post-inflammatory hyperpigmentation, herpes labialis, and acne breakouts. These results support the application of AFL as a viable treatment option for melasma, particularly in refractory and severe cases. Rational parameterization or combination therapy may lead to significant clinical improvement with fewer complications.

Awareness of sun exposure risks and photoprotection for preventing pigmentary disorders in Asian populations: Survey results from three Asian countries and expert panel recommendations

BACKGROUND

In this article, we review and discuss the photoprotection behavior of Asians based on the literature, along with a subanalysis of an original online survey, and make recommendations to optimize photoprotection for Asian populations to prevent photoaging and pigmentary disorders.

METHODS

An international panel of eight dermatologists from Asia (China, Korea, Japan, Singapore, Indonesia, and Vietnam) met to discuss sunscreen photoprotection for Asian patients. Additionally, a subanalysis of an online survey by 3000 respondents from three Asian countries (China, Indonesia, and Japan) investigated general public awareness and attitudes to sun exposure.

RESULTS

A pre-meeting survey of the eight experts from Asia showed key concerns of Asian patients consulting dermatologists are pigmentary disorders, especially actinic/senile lentigo, post-inflammatory hyperpigmentation, melasma, vitiligo, and Hori's nevus. The survey subanalysis of participants from China, Indonesia, and Japan with predominantly Fitzpatrick skin types (FST) II to IV revealed that they are particularly concerned about sun exposure causing photoaging and pigmentary disorders. Most of the respondents indicated they have limited knowledge on sunlight radiation and appropriate sunscreen protection factors. Only 22%, 13%, and 3% for China, Indonesia, and Japan, respectively, systematically use multiple protective measures (using sunscreen, avoiding midday sun, staying in the shade, wearing a hat, protective clothing, and sunglasses) when exposed to the sun.

CONCLUSIONS

Further education is needed for Asian populations on the importance of comprehensive daily photoprotection, including broad-spectrum sunscreen, with high UVA and visible light protection, to reduce and prevent photoaging and pigmentary disorders.

Pigmentation of lower limbs: Contribution of haemosiderin and melanin in chronic venous insufficiency and related disorders

BACKGROUND

To determine the composition of skin pigmentation in chronic venous insufficiency (CVI) and other less common vascular conditions of lower limbs.

METHODS

Forty-five skin biopsies were obtained from 17 patients. Samples were taken from pigmented regions and compared with control non-lesional samples from the same patient. Perl's Prussian Blue was used to identify haemosiderin and Schmorl's for melanin.

RESULTS

Seven patients presented with CVI, one with concurrent livedo vasculopathy (LV). One patient had LV only. Two patients had acroangiodermatitis (AAD). Six patients had post-sclerotherapy pigmentation (PSP), one with concurrent post-inflammatory hyperpigmentation (PIH). One patient had PIH only. The predominant pigment in CVI samples was haemosiderin. C5-C6 patients showed increased epidermal melanin. LV, AAD, and PSP samples showed dermal haemosiderin but no increase in epidermal melanin. PIH samples showed prominent epidermal melanin whilst no haemosiderin was detected.

CONCLUSION

The predominant pigment in CVI and other vascular conditions was haemosiderin. Melanin was present in later stages of CVI (C5-C6) and in PIH.

Tetrahedral framework nucleic acid loaded with glabridin: A transdermal delivery system applicated to anti-hyperpigmentation

Topical application of tyrosinase inhibitors, such as hydroquinone and arbutin, is the most common clinical treatment for hyperpigmentation. Glabridin (Gla) is a natural isoflavone that inhibits tyrosinase activity, free radical scavenging, and antioxidation. However, its water solubility is poor, and it cannot pass through the human skin barrier alone. Tetrahedral framework nucleic acid (tFNA), a new type of DNA biomaterial, can penetrate cells and tissues and can be used as carriers to deliver small-molecule drugs, polypeptides, and oligonucleotides. This study aimed to develop a compound drug system using tFNA as the carrier to transport Gla and deliver it through the skin to treat pigmentation. Furthermore, we aimed to explore whether tFNA-Gla can effectively alleviate the hyperpigmentation caused by increased melanin production and determine whether tFNA-Gla exerts substantial synergistic effects during treatment. Our results showed that the developed system successfully treated pigmentation by inhibiting regulatory proteins related to melanin production. Furthermore, our findings showed that the system was effective in treating epidermal and superficial dermal diseases. The tFNA-based transdermal drug delivery system can thus develop into novel, effective options for non-invasive drug delivery through the skin barrier.

Conditions and Factors That Raise the Risk of Developing Skin Lesions After Shingles

Objective

To understand the situation and risk factors of skin lesions following the eruption of shingles.

Methods

We selected 275 patients with shingles who had been diagnosed and treated in the Dermatology Department of Changshu No. 1 People's Hospital between July 2017 and March 2022. Age, gender, skin lesion site, skin lesion type, prodromal pain, history of diabetes, history of hypertension, history of other immune diseases, as well as other pertinent clinical data, were collected. The severity and pain of patients with severe shingles were evaluated, and their fasting blood sugar and plasma albumin were measured for routine antiviral treatment. They were followed up 6 months-the types of skin lesions and pertinent clinical data were compared, and the risk factors for skin lesions were analyzed.

Results

There were no statistically significant differences in gender, age, or site among the different types of skin lesions (P > 0.05). The severity of skin lesions, acute pain, history of diabetes, history of scars, low immune function, combined with hypoproteinemia, squeezing and stripping behavior, and post-herpetic neuralgia (PHN) were significantly associated with skin lesions (P < 0.05). The results of multivariate analysis showed that: age ≥60 years old, severe skin injury combined with diabetes, low immune function, scar history, squeezing and stripping were independent risk factors for the development of skin lesions due to shingles.

Conclusion

There is no significant difference in age, gender, site, or other characteristics between the types of skin lesions due to shingles. The independent risk factors of skin lesions due to shingles are old age, severe rash, history of scars, diabetes, low immunity, squeezing, and peeling.

Promoting New Approach Methodologies (NAMs) for research on skin color changes in response to environmental stress factors: tobacco and air pollution

Aging is one of the most dynamic biological processes in the human body and is known to carry significant impacts on individuals' self-esteem. Skin pigmentation is a highly heritable trait made possible by complex, strictly controlled cellular and molecular mechanisms. Genetic, environmental and endocrine factors contribute to the modulation of melanin's amount, type and distribution in the skin layers. One of the hallmarks of extrinsic skin aging induced by environmental stress factors is the alteration of the constitutive pigmentation pattern clinically defined as senile lentigines and/or melasma or other pigmentary dyschromias. The complexity of pollutants and tobacco smoke as environmental stress factors warrants a thorough understanding of the mechanisms by which they impact skin pigmentation through repeated and long-term exposure. Pre-clinical and clinical studies demonstrated that pollutants are known to induce reactive oxygen species (ROS) or inflammatory events that lead directly or indirectly to skin hyperpigmentation. Another mechanistic direction is provided by Aryl hydrocarbon Receptors (AhR) which were shown to mediate processes leading to skin hyperpigmentation in response to pollutants by regulation of melanogenic enzymes and transcription factors involved in melanin biosynthesis pathway. In this context, we will discuss a diverse range of New Approach Methodologies (NAMs) capable to provide mechanistic insights of the cellular and molecular pathways involved in the action of environmental stress factors on skin pigmentation and to support the design of raw ingredients and formulations intended to counter their impact and of any subsequently needed clinical studies.

Clinical application of 675 nm laser therapy for dorsal hand skin hyperpigmentation

BACKGROUND

Noninvasive skin rejuvenation treatment is growing in recognition to aesthetic medicine.

AIM

The objective of the study was to assess the efficacy and the safety of the 675-nm laser source treatment of photodamaged hands.

MATERIALS AND METHODS

The study included 21 patients (6 males and 15 females) with a mean age of 63 (± 9) years. Patients were treated with -two to three sessions of the 675-nm laser with a 1-month interval between sessions. Photos of each patient were collected at baseline, and 3 months after the last laser session. The 5-point Global Aesthetic Improvement Scale (GAIS) was recorded with their final assessment session (3 months).

RESULTS

The total GAIS scores showed satisfactory results: 15 patients (71%) experienced 4 score (excellent improvement) changes and 6 patients (29%) experienced 3 score (good improvement) changes. Clinical images showed good efficacy and visible aesthetic results for the management of photodamaged skin. No serious adverse effects were recorded.

CONCLUSION

This study demonstrates the safety and efficacy of for the aesthetic improvement of skin pigmentation and texture for photodamaged hands.

Reinforcing Photoprotection for Skin of Color: A Narrative Review

Skin of color (SOC) is characterized by increased tendency for tanning and decreased likelihood of sunburns due to the attenuation of sunlight by epidermal melanin. Although this contributes to the decreased incidence of skin cancer among SOC populations, individuals with SOC remain susceptible to various health consequences associated with sun exposure, including non-melanoma skin cancer, photoaging, pigmentary disorders, and photodermatoses - many of which not only present differently, but also disproportionately affect SOC. Prior epidemiological studies have found lower prevalence of sun protection behaviors among individuals with SOC, particularly in sunscreen use, signifying an unmet area for improvement in the prevention of sun-induced dermatologic conditions in these populations. The objective of this narrative review was to summarize the biology and health consequences of sun exposure in SOC, as well as cognitive and behavioral factors that affect the practice of photoprotection behaviors in SOC populations. We also review prior interventions that have been used to enhance photoprotection knowledge and behaviors among individuals with SOC, either in racially and ethnically diverse communities or within specific SOC populations.

Disorders of Facial Hyperpigmentation

Disorders of hyperpigmentation are common and challenging conditions which can arise due to a myriad of etiologic factors. Many of them can present across skin types but are more common in skin of color individuals with Fitzpatrick skin types III-VI. Facial hyperpigmentation, in particular, can have a significant impact on the quality of life of affected individuals due to its increased visibility. This article provides a comprehensive review of disorders of facial hyperpigmentation including epidemiology, pathogenesis, diagnostic considerations, and treatment approaches for these conditions.

Skin Pigmentation Types, Causes and Treatment-A Review

Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance, psychological health, and social functioning are all impacted by a sizable number of skin conditions that cause pigmentary abnormalities. Hyperpigmentation, where pigment appears to overflow, and hypopigmentation, where pigment is reduced, are the two major classifications of skin pigmentation. Albinism, melasma, vitiligo, Addison's disease, and post-inflammatory hyperpigmentation, which can be brought on by eczema, acne vulgaris, and drug interactions, are the most common skin pigmentation disorders in clinical practice. Anti-inflammatory medications, antioxidants, and medications that inhibit tyrosinase, which prevents the production of melanin, are all possible treatments for pigmentation problems. Skin pigmentation can be treated orally and topically with medications, herbal remedies, and cosmetic products, but a doctor should always be consulted before beginning any new medicine or treatment plan. This review article explores the numerous types of pigmentation problems, their causes, and treatments, as well as the 25 plants, 4 marine species, and 17 topical and oral medications now on the market that have been clinically tested to treat skin diseases.

Evaluation of the Reduction of Skin Hyperpigmentation Changes under the Influence of a Preparation Containing Kojic Acid Using Hyperspectral Imaging—Preliminary Study

Aim: The aim of this study was to demonstrate the effects of using a preparation containing kojic acid on skin hyperpigmentation using hyperspectral imaging, which enables a quantitative assessment of the effect of the preparation used on the reduction of skin discoloration. Materials and methods: Preliminary studies were carried out on 12 patients with post-acne skin. A hyperspectral camera with a spectral range of 400–1000 nm was used to image skin hyperpigmentation before and after the application of 3% kojic acid. Hyperspectral profiles were analyzed, and image analysis and processing methods were applied. Results: Studies performed using a hyperspectral camera have shown that kojic acid reduces skin discoloration by increasing skin brightness in 75% of patients tested, reducing skin contrast in approximately 83% and increasing skin homogeneity in approximately 67% of patients.

Review of Laser Treatments for Post-Inflammatory Hyperpigmentation in Skin of Color

Post-inflammatory hyperpigmentation is an extremely common disorder of pigmentation in skin of color. It most frequently and severely affects phototypes that are rich in melanin and often has a chronic and unpredictable course. It presents significant treatment challenges and often requires a multi-factorial approach. We review the literature available for the optimal use of laser-based devices in the treatment of post-inflammatory hyperpigmentation, particularly for Fitzpatrick skin phototypes III-VI. For the treatment of post-inflammatory hyperpigmentation in skin of color, lasers remain second line to topical agents based on the variable response, cost, and risk of complications with laser use. For post-inflammatory hyperpigmentation resistant to topicals, laser devices, particularly neodymium:yttrium-aluminum-garnet and fractional photothermolysis systems, can provide adjunctive treatment in skin of color patients when appropriate parameters are used. Future studies would benefit from an objective and consistent assessment to assist with a systematic analysis.

Inflammatory response: The target for treating hyperpigmentation during the repair of a burn wound

Hyperpigmentation is a common complication in patients with burn injuries during wound healing; however, the mechanisms underlying its occurrence and development remain unclear. Recently, postinflammatory hyperpigmentation (PIH) was found to result from overproduction of melanin. Local or systemic inflammatory responses are often observed in patients who develop hyperpigmentation. However, we lack studies on the relationship between PIH and burn injury. Therefore, we comprehensively reviewed the existing literature on the melanogenesis of the skin, inflammatory mechanisms in pigmentation, and local or systemic alteration in inflammatory cytokines in patients suffering from burn trauma to elucidate the relationship between PIH and burn injury. We believe that this review will guide further research on regulating melanin production in the burn management process.

Efficacy and Best Mode of Delivery for Tranexamic Acid in Post-Inflammatory Hyperpigmentation: A Systematic Review

Background

Post-inflammatory hyperpigmentation (PIH) is skin hyperpigmentation that occurs due to any inflammatory condition. Triggering the melanocytes by inflammation leads to melanin overproduction and deposition. Tranexamic acid (TXA) is an antifibrinolytic medication prescribed to treat bleeding. Recently, there are some studies about the use of TXA in the treatment of PIH.

Objective

The aim of this study is to identify the efficacy and the best mode of delivery for tranexamic acid in the treatment of PIH.

Methods

This systematic review is reported in accordance with PRISMA guidance. We included all relevant English-language studies that were published up to September 2022 in the following electronic databases: Cochrane Library, PubMed, Embase, and Google Scholar. The initial search yielded 61 articles, 9 of which were included after applying inclusion and exclusion criteria.

Results

The systematic review included a total of 196 patients who were over the age of 16 years old. Tranexamic acid was delivered orally in 4 studies, topically in 2 studies, and both simultaneously in 1 study. In addition, intradermal injection was used in 2 other studies. Almost all studies advocated the use of all routes for accelerating the clearance of hyperpigmentation with more favor towards topical and intradermal routes due to their mild reported side effects when compared to oral routes.

Conclusion

Intradermal TXA is considered the best route, which exhibits fewer side effects with less cost and excellent outcomes, while oral TXA is found to be less preferable than other routes due to the incidence of undesirable adverse events.

Post-Inflammatory Hyperpigmentation in Dark Skin: Molecular Mechanism and Skincare Implications

Human skin is characterized by significant diversity in color and tone, which are determined by the quantity and distribution of melanin pigment in the epidermis. Melanin absorbs and reflects ultraviolet radiation (UVR), preventing the damage to genomic DNA in the epidermis and degradation of collagen in the dermis; therefore, darker skin types are thought to be well protected from the photodamage because of the high melanin content. However, increased content of melanin in combination with the extrinsic stress factors causing inflammation such as excess UVR, allergic reactions, or injury can also frequently lead to cosmetic problems resulting in discoloration and scarring. This review summarizes current knowledge on histopathology and likely molecular signatures of one of the most common problems, post-inflammatory hyperpigmentation (PIH). The mechanisms proposed so far are subsequently discussed in the context of other factors characterizing darker skin types. This includes the common cellular features, organization of upper skin layers, and major biomarkers, with particular emphasis on increased propensities to systemic and localized inflammation. Enhanced or prolonged inflammatory responses can not only affect the process of melanogenesis but also have been implicated in injury-related skin pathologies and aging. Finally, we summarize the major cosmetic treatments for PIH and their known anti-inflammatory targets, which can be beneficial for darker skin tones and combined with broad-spectrum filters against UVR.

Dermoscopy aids in differentiating primary cutaneous amyloidosis and post-inflammatory hyperpigmentation: A clinico-dermoscopic-histopathaological study

BACKGROUND

Primary cutaneous amyloidosis (PCA) and post-inflammatory hyperpigmentation (PIH) are common causes of cutaneous hyperpigmentation that are usually diagnosed clinically. However, their presentations are sometimes atypical, and their differentiation is difficult. Dermoscopy is a valuable diagnostic tool for pigmented diseases that might aid in their diagnosis.

OBJECTIVE

To describe the characteristic dermoscopic features of PCA and PIH together with histopathological correlation, and to differentiate between these conditions in a non-invasive way.

METHODS

Fifty-two patients with PCA (n = 26) and PIH (n = 26) were enrolled. A detailed history, skin examination, dermoscopic examination using handheld and video dermoscopy, and histopathological evaluation were performed.

RESULTS

A statistically significant difference could be detected between PCA and PIH in terms of the duration of the disease (p = 0.027), symmetry (p = 0.044), rippling (p < 0.001), and back affection (p = 0.048). On dermoscopic examination, central hubs were seen more in the PCA group (p < 0.001) with different patterns of peripheral pigmentation. Histopathologically, the number of melanophages per high-power field was significantly higher in the PCA group (p = 0.013).

CONCLUSION

The results of this study shed the light on the potential of dermoscopy as a non-invasive diagnostic tool in differentiating between doubtful cases of PCA and PIH.

Laser treatment of acne scarring in skin of colour

Acne vulgaris is a chronic inflammatory skin disorder that affects patients of all skin types. Acne scarring affects up to 95% of patients. Laser treatment is the most effective treatment for acne scarring. Adverse effects (AEs) include pain, infection, erythema, postinflammatory hyperpigmentation (PIH), hypopigmentation and scarring. Patients with darker skin types are more prone to developing PIH, arising as a result of inflammation, which can be intrinsic or extrinsic. There is concern that laser treatment may not be suitable for patients with skin of colour (SOC) due to the risks of AEs. However, the use of appropriate treatment protocols can help to mitigate these risks. Clinicians should consider the type of acne scarring and skin type of the patient when choosing the most appropriate laser. Laser treatments should be offered to patients with SOC, who should be fully informed of the risks before embarking on treatment. It is important to note that no treatment will eliminate scarring completely, but lasers can significantly improve the appearance of acne scars. Laser treatment for acne scarring can be performed safely and effectively when tailored to the patient's needs and skin type. Further studies are needed to evaluate the use of lasers for patients with SOC.

Treatment of hyperpigmentation after burn: A literature review

OBJECTIFY

Skin pigmentation disorders are one of the most frequent sequelae after burn injury. While these conditions often improve over time, some are permanent and cause severe psychological disorders (especially on the face). Given the frequency of these disorders and their benign nature, the scientific community has great difficulty postponing these patient follow-ups. Publications on their management are rare, and there is no consensus on the gold standard treatment for skin dyschromia. Herein, we performed a literature review including the various treatments currently proposed to manage these hyperpigmentations.

METHODS

All reported articles up to February 2021 were reviewed on Pubmed. Studies on the treatment of hyperpigmented scars were included if they were secondary to burn injuries. Excluded articles evaluated transient treatments, such as makeup, and articles on inflammatory hyperpigmentation without etiological details or not secondary to burns.

RESULTS

201 articles were identified, and 13 studies were included. Topical creams used in inflammatory hyperpigmented lesions such as hydroquinone and first-line retinoids are controversial due to their inconstant efficacy. Various types of laser and pulsed light treatments have shown their effectiveness but can also aggravate pigmentation.

CONCLUSION

Dyschromia after burn remains a therapeutic challenge. Hyperpigmentations after burn should be treated on a case-by-case basis, using data from the literature, clinical experience and measuring the risk/benefit ratio.

Solamargine Alleviated UVB-Induced Inflammation and Melanogenesis in Human Keratinocytes and Melanocytes via the p38 MAPK Signaling Pathway, a Promising Agent for Post-inflammatory Hyperpigmentation

Post-inflammatory hyperpigmentation (PIH) is a common acquired pigmentary disorder occurring after skin inflammation or injury. Ultraviolet B irradiation could exaggerate PIH clinically due to its effect on promoting cutaneous inflammation and melanogenesis in keratinocytes and melanocytes, respectively. Solamargine (SM), a steroidal alkaloid glycoside extracted from Solanum undatum, significantly inhibits Ultraviolet B (UVB)-induced pro-inflammatory cytokines IL-1α, IL-1β, IL-8, and IFN-γ, as well as paracrine melanogenic factors ET-1, α-MSH, and bFGF in human keratinocytes. Additionally, SM significantly attenuated UVB-induced melanin synthesis in human epidermal melanocytes through down-regulation of tyrosinase activity and expression of MITF, TRP-1, TRP-2, and tyrosinase. SM exerted an anti-inflammatory effect in UVB-irradiated keratinocytes through the p38 MAPK/Nrf2/HO-1 signaling pathway. With its anti-inflammatory and whitening effect, SM may improve PIH through paracrine regulations of keratinocytes and direct action on melanocytes, making it a promising agent for PIH.

Prevalence of skin diseases in school-age children

BACKGROUND

The prevalence of community-based skin diseases, especially among school-age children, depends on topography, climate, and age of population.

OBJECTIVE

We determined the prevalence of skin diseases among community-based primary school-age children and identified demographic characteristics in relation to particular skin conditions.

METHODS

This was a cross-sectional descriptive survey study of a subproject school cohort in children aged 5-14 years of 2 community-based primary schools. Demographic data and whole-body skin examination were collected. The association of individual skin conditions was analysed by using bivariate and multivariable binary logistic regression.

RESULTS

A total of 556 children were enrolled in this study. Of these, 90.2% had at least 1 skin disease. The most common skin disease was postinflammatory hyperpigmentation (PIH) (58.3%), followed by nevus/mole (40.1%), insect bite reaction (28.0%), acanthosis nigricans (20.0%), acne (13.7%), and pityriasis alba (12.9%). There was an increase of body mass index (BMI) in PIH and acanthosis nigricans with the adjusted odds ratios of 2.01 (95% confidence interval [CI] 1.40-2.87, P < 0.001) and 1.93 (95% CI 1.49-2.49, P < 0.001), respectively. Insect bite reaction was related to PIH with the adjusted odds ratio of 5.66 (95% CI 3.15-10.17, P = 0.001).

CONCLUSIONS

The most common skin disease in community-based primary school-age children is PIH which related to acanthosis nigricans and insect bite reaction. A decrease of BMI may lower the risk for PIH and acanthosis nigricans. Education on common skin diseases is recommended for both community-based schools and school-age children.

Interferon-gamma induces melanogenesis via post-translational regulation of tyrosinase

Melanogenesis (melanin pigment production) in melanocytes is canonically stimulated by the alpha melanocyte stimulating hormone (αMSH), which activates the cyclic-AMP-mediated expression of the melanocyte inducing transcription factor (MITF) and its downstream melanogenic genes, including the principal rate-limiting melanogenic enzyme tyrosinase (TYR). Here, we report that interferon-gamma (IFNG; type II interferon), but not interferon-alpha (a type I interferon), induces a noncanonical melanogenic pathway in mouse and human melanocytic cells. Inhibition of IFNG pathway by the JAK1/2 inhibitor ruxolitinib or knocking out Stat1 gene abrogated the IFNG-induced melanogenesis. Interestingly, IFNG-induced melanogenesis was independent of MITF. IFNG markedly increased the TYR protein expression but did not affect the mRNA expression, suggesting a post-translational regulatory mechanism. In contrast, IFNG had no effect on the expression of other melanogenesis-related proteins, for example, tyrosinase-related protein 1 (TYRP1) and dopachrome tautomerase (DCT). Glycosidase digestion assays revealed that IFNG treatment increased the mature glycosylated form of TYR, but not its de novo synthesis. Moreover, cycloheximide chase assay showed that degradation of TYR was decreased in IFNG-treated cells. These results suggest that the IFNG-STAT1 pathway regulates melanogenesis via regulation of the post-translational processing and protein stability of TYR.

Preferential stimulation of melanocytes by M2 macrophages to produce melanin through vascular endothelial growth factor

Post-inflammatory hyperpigmentation is a skin discoloration process that occurs following an inflammatory response or wound. As the skin begins to heal, macrophages first exhibit a proinflammatory phenotype (M1) during the early stages of tissue repair and then transition to a pro-healing, anti-inflammatory phenotype (M2) in later stages. During this process, M1 macrophages remove invading bacteria and M2 macrophages remodel surrounding tissue; however, the relationship between macrophages and pigmentation is unclear. In this study, we examined the effect of macrophages on melanin pigmentation using human induced pluripotent stem cells. Functional melanocytes were differentiated from human induced pluripotent stem cells and named as hiMels. The generated hiMels were then individually cocultured with M1 and M2 macrophages. Melanin synthesis decreased in hiMels cocultured with M1 macrophages but significantly increased in hiMels cocultured with M2 macrophages. Moreover, the expression of vascular endothelial growth factor was increased in M2 cocultured media. Our findings suggest that M2 macrophages, and not M1 macrophages, induce hyperpigmentation in scarred areas of the skin during tissue repair.

Sebocytes contribute to melasma onset

Melasma is a hyperpigmentary disorder with photoaging features, whose manifestations appear on specific face areas, rich in sebaceous glands (SGs). To explore the SGs possible contribution to the onset, the expression of pro-melanogenic and inflammatory factors from the SZ95 SG cell line exposed to single or repetitive ultraviolet (UVA) radiation was evaluated. UVA up-modulated the long-lasting production of α-MSH, EDN1, b-FGF, SCF, inflammatory cytokines and mediators. Irradiated SZ95 sebocyte conditioned media increased pigmentation in melanocytes and the expression of senescence markers, pro-inflammatory cytokines, and growth factors regulating melanogenesis in fibroblasts cultures. Cocultures experiments with skin explants confirmed the role of sebocytes on melanogenesis promotion. The analysis on sebum collected from melasma patients demonstrated that in vivo sebocytes from lesional areas express the UVA-activated pathways markers observed in vitro. Our results indicate sebocytes as one of the actors in melasma pathogenesis, inducing prolonged skin cell stimulation, contributing to localized dermal aging and hyperpigmentation.

A Randomized, Double Blinded, Split-Face Study of the Efficacy of Using a Broad Spectrum Sunscreen with Anti-Inflammatory Agent to Reduce Post Inflammatory Hyperpigmentation After Picosecond Laser

BACKGROUND

Post inflammatory hyperpigmentation (PIH) is a sequela of laser procedures observed commonly in darker-skin individuals. In general, regular UV filters are beneficial in preventing PIH, but the comparison with sunscreen containing anti-inflammatory ingredients remains unexplored.

OBJECTIVE

To compare the efficacy of a sunscreen with anti-inflammatory agent (sunscreen A) in the reduction of PIH after a picosecond laser with that of regular sunscreen (sunscreen B).

METHODS

Fifty-nine acne vulgaris and acne scar patients with skin phototypes III and IV were treated with 1 session of picosecond laser with the microlens array to the whole face. Sunscreens A and B were randomized to be applied on either side of the face. Hyperpigmentation assessed by brown score mode on Visia^®, acne quantity, porphyrins and patient satisfaction were evaluated at baseline, weeks 1, 2, 4 and 6.

RESULTS

Sunscreen A caused a higher reduction of the brown score compared to the other side but there was no statistically significant difference. Interestingly, a significant decrease of inflammatory acne lesions compared with baseline was observed as early as week 2 on the sunscreen A side (weeks 2, 4 and 6; P = 0.017, P = <0.001, and P = <0.001, respectively). Compared with sunscreen B, levels of porphyrins on sunscreen A side were significantly less at weeks 1 and 6 (weeks 1 and 6; P = 0.022 and P = 0.029, respectively).

CONCLUSION

This study demonstrated a tendency towards lower post-laser pigmentation when the sunscreen with anti-inflammatory agents was applied. This product also had an effective outcome as an adjunctive treatment option of acne vulgaris.

THAI CLINICAL TRIALS REGISTRY ID

TCTR20210305004 (URL: http://www.thaiclinicaltrials.org/show/TCTR20210305004).

Photoprotection for Skin of Color

Photoprotection behaviors can mitigate skin damage caused by ultraviolet radiation, and common methods include seeking shade, avoiding sun exposure during peak daylight hours, wearing sun-protective clothing, applying sunscreen, and using sunglasses. While the role of sun protection in preventing sunburns, photoaging, and skin cancer is well established in fair-skinned populations, individuals with skin of color (SOC) are presumed to suffer fewer negative effects from solar radiation. Thus, the importance of photoprotection in this population is understudied and may be underestimated. In SOC populations, sun exposure is known to cause pigmentary disorders, photoaging, and basal cell carcinoma (BCC), highlighting the potential benefits of photoprotection. Although SOC populations tend to practice photoprotection by seeking shade and wearing sun-protective clothing, survey and interview-based studies have consistently found relatively low use of sunscreen among these populations. Common motivators for photoprotection in individuals with SOC include preventing sunburn and pigmentation, with the prevention of skin cancer being a less important reason. As a skin cancer risk behavior, indoor tanning is relatively rare in SOC populations, but its use may increase with acculturation to US norms. While more studies are necessary to clarify whether photoprotection behaviors may decrease skin cancer-related mortality in SOC populations, regular dermatologic care and counseling on photoprotection remain essential in patients with SOC for overall skin health.

Implications of Oxidative Stress in the Pathogenesis and Treatment of Hyperpigmentation Disorders

Oxidative stress represents an imbalance between the generation of reactive oxygen and nitrogen species and the ability of antioxidant systems to decompose those products. Oxidative stress is implicated in the pathogenesis of hyperpigmentation, hypopigmentation, melanoma, and other skin diseases. Regulatory networks involving oxidative stress and related pathways are widely represented in hypopigmentation diseases, particularly vitiligo. However, there is no complete review into the role of oxidative stress in the pathogenesis of hyperpigmentation disorders, especially regarding associations involving oxidative stress and cellular signaling pathways. Here, we review oxidative and antioxidant systems, oxidative stress-induced signal transduction mechanisms, and effects of antioxidant drugs used in preclinical and clinical settings in hyperpigmentation disorders.

Effects of Topical Retinoids on Acne and Post-inflammatory Hyperpigmentation in Patients with Skin of Color: A Clinical Review and Implications for Practice

Acne is a common cause for post-inflammatory hyperpigmentation (PIH), particularly in patients with skin of color (SOC), and PIH is often more distressing to patients than the acne itself. Topical retinoids are approved for the treatment of acne and for pigmentation disorders such as melasma or mottled hyperpigmentation associated with photodamage; moreover, they have been shown to reduce hyperpigmentation in patients with SOC. Therefore, treatment with topical retinoids should be started as early as possible unless contraindicated. Use of novel formulations or application of commonly recommended moisturizers may help reduce irritation. Combining retinoids with other topical agents and procedures such as superficial chemical peels can help to improve hyperpigmentation. Primary acne lesions are likely to improve weeks before PIH resolves and helping patients manage their expectations may reduce frustration. Providing clinicians and researchers with more education about the presentation and management of dermatologic conditions in patients with SOC is also recommended.

Urea-extracted sericin is potentially better than kojic acid in the inhibition of melanogenesis through increased reactive oxygen species generation

Background

Hyperpigmentation is a skin disorder, which is caused by an excess production of melanin. The reduction in melanin content without causing undesirable effects is required for the treatment of hyperpigmentation. Sericin is increasingly used as a hyperpigmentation treatment because of its antityrosinase activity. However, the various methods of sericin extraction have an effect on the composition and biological properties. The purpose of this study was to investigate the antioxidant and anti-melanogenic properties of sericin using different extraction methods including acid, base, heat, and urea extraction.

Methods

The chemical properties of extracted sericin were assessed in terms of amino acid components, thermal behavior, and UV–vis absorption. The inhibitory effects of sericin on melanogenesis were explored by determining the melanin content and cellular tyrosinase activity in B16F10 cells.

Results

Sericin from urea extraction provided different properties when compared with the other extraction methods. Our results indicate that urea-extracted sericin reduced the melanin content and cellular tyrosinase activity more effectively than the other extraction methods. Interestingly, the potential anti-melanogenic activity was more effective than kojic acid, a depigmenting agent used to treat hyperpigmentation. Moreover, treatment of urea-extracted sericin induced reactive oxygen species and subsequently activated antioxidant activity in B16F0 cells.

Conclusions

Our results present the potential inhibitory effect of urea-extracted sericin on melanogenesis. The therapeutic potential of urea-extracted sericin can be used in the treatment of hyperpigmentation and its complications.

•

The anti-melanogenic effect of urea-extracted sericin was significantly better than kojic acid.

•

Urea-extracted sericin suppressed melanin synthesis and tyrosinase activity through the induction of ROS.

•

Urea-extracted sericin activated the expression of Nrf2 and its downstream target genes for modulation of melanogenesis.

•

Urea-extracted sericin could be considered as an effective anti-melanogenic agent.

Laser-Assisted Drug Delivery of Tranexamic Acid by Picosecond Laser in Postinflammatory Hyperpigmentation: A Split-Area Double Blind Randomized Prospective Study

Background: Tranexamic acid has been reported to benefit the treatment of postinflammatory hyperpigmentation (PIH). Laser-assisted drug delivery (LADD) could facilitate the efficacy of topically applied drugs into the dermis. This split-area randomized prospective study aims to assess whether early utilization of the LADD procedure with tranexamic acid delivery followed by picosecond lasers can attenuate the PIH better than the utilization of picosecond lasers alone. Patients and methods: Ten post-traumatic cases of PIH in 10 patients (8 female and 2 male) with an average age of 34.2 ± 11.2 years were included in this clinical trial. Using block randomization to determine the treatment side, one side of each area of the PIH was separated from the midline into two halves belonging to the control and tranexamic acid groups. The half area of the tranexamic acid group was further topically applied with 10% tranexamic acid solution. This procedure was repeated every 6 weeks, four times in total. Results: The self-assessment of the hyperpigmentation and overall satisfaction of the treatment outcome were not significantly different between the treatment and control sides. Conclusions: This split-area study revealed that, compared with picosecond alone, there was no significant difference adopting tranexamic acid in LADD after nonablative fractional picosecond laser for PIH.

An Open-Label Study Assessing the Efficacy and Tolerability of a Skincare Regimen in Subjects of Different Ethnicities with Moderate-to-Severe Hyperpigmentation

Background

Hyperpigmentation is a common cosmetic concern that significantly impacts self‐esteem. A skincare regimen has been developed to improve the appearance, tone, texture, and luminosity of subjects with facial hyperpigmentation (Even Up^® Hyperpigmentation Regimen; Colorescience, Inc., Carlsbad, CA).

Aims

The objective of this open‐label trial was to assess the efficacy and tolerability of this regimen for treating facial hyperpigmentation.

Patients/Methods

Subjects with moderate‐to‐severe facial hyperpigmentation (N = 33) were randomized to those not using prescription, advanced or physician‐dispensed skin care products (Group A, n = 23) and those currently using prescription, advanced or physician‐dispensed skincare products for facial hyperpigmentation (Group B, n = 10). Both groups were provided three skincare products comprising the hyperpigmentation regimen and instructions for use. Subjects were evaluated at baseline and Weeks 2, 4, 8 and 12.

Results

The overall median (range) baseline MASI score at baseline was 9.0 (2, 31), decreasing by 0.0 (−7, 0) points at Week 2 (p = 0.002), 0.6 (−8, 0) points at Week 4 (p < 0.0001), 1.5 (−16, 0) points by Week 8 (p < 0.0001) and 2.4 (−20, 0) points at Week 12 (p < 0.0001). At Week 12, the overall median improvement in MASI score was 26% and higher for Group B (32% vs. 22%). By Week 2, subjects reported lighter, less noticeable brown spots (76%), brighter, more luminous skin (88%), more even skin tone (67%), and healthier look and feel (85%). Improvements continued throughout the study. No adverse events were observed or reported.

Conclusions

This regimen addresses facial hyperpigmentation and protects skin against the damaging effects of ultraviolet and high energy visible light (HEV). It is safe to use on all skin types and tones.

Addressing Human Skin Ethnicity: Contribution of Tissue Engineering to the Development of Cosmetic Ingredients

Recent publications describe various skin disorders in relation to phototypes and aging. The highest phototypes (III to VI) are more sensitive to acne, with the appearance of dark spots due to the inflammation induced by Cutibacterium acnes (previously Propionibacterium acnes). Dryness with aging is due to a lower activity of specific enzymes involved in the maturation of lipids in the stratum corneum. To observe and understand these cutaneous issues, tissue engineering is a perfect tool. Since several years, pigmented epidermis with melanocytes derived from specific phototypes allow to develop in vitro models for biological investigations. In the present study, several models were developed to study various skin disorders associated with phototypes and aging. These models were also used to evaluate selected ingredients’ ability to decrease the negative effects of acne, inflammation, and cutaneous dryness. Hyperpigmentation was observed on our reconstructed pigmented epidermis after the application of C. acnes, and pollutant (PM10) application induced increased inflammatory cytokine release. Tissue engineering and molecular biology offer the capability to modify genetically cells to decrease the expression of targeted proteins. In our case, GCase was silenced to decrease the maturation of lipids and in turn modify the epidermal barrier function. These in vitro models assisted in the development of ethnic skin-focused cosmetic ingredients.

Progress in Microdermal Grafting for Color Regeneration of White Scars

BACKGROUND

Microdermal grafting with knife-cut, partially de-epithelialized skin can regenerate color in white (hypopigmented) scars. However, the scalp has more melanocytes, and dermabrasion can preserve more melanocytes than knife cutting during partial de-epithelialization.

OBJECTIVES

The aim of this study was to evaluate the color regeneration results and complications of various microdermal grafting procedures for white scar color regeneration.

METHODS

Two refinements to an existing microdermal grafting technique for treating white scars were described: dermabrasion, rather than knife cutting, was used to partially de-epithelialize skin, and melanocyte donor sites were harvested from the scalp, rather than from skin. A review was performed of 65 cases in which various combinations of these refinements were used to treat scars on the face and forearms.

RESULTS

Sixty-five patients (36 forearms; 29 faces) were treated, 40 receiving 1 session, 23 receiving 2 sessions, and 2 receiving 3 sessions of treatment. The follow-up was 6.5 months (range, 4-16 months). The use of both technique refinements produced approximately 15% better color generation than the original procedure after 1 session of treatment and approximately 20% better than the original procedure after 2 sessions. Histologic immunostaining showed that the dermabrasion method preserved more melanocytes around the epidermal-dermal region, and that the scalp has richer melanocytes than skin. The complication rate was reduced.

CONCLUSIONS

The use of the scalp as the donor site and partial de-epithelialization by dermabrasion can be safely incorporated into a previously developed microdermal grafting procedure for better color regeneration of white scars.

LEVEL OF EVIDENCE: 4

Identification of Sitogluside as a Potential Skin-Pigmentation-Reducing Agent through Network Pharmacology

Many traditional Chinese medicines (TCMs) with skin-whitening properties have been recorded in the Ben-Cao-Gang-Mu and in folk prescriptions, and some literature confirms that their extracts do have the potential to inhibit pigmentation. However, no systematic studies have identified the specific regulatory mechanisms of the potential active ingredients. The aim of this study was to screen the ingredients in TCMs that inhibit skin pigmentation through a network pharmacology system and to explore underlying mechanisms. We identified 148 potential active ingredients from 14 TCMs, and based on the average “degree” of the topological parameters, the top five TCMs (Fructus Ligustri Lucidi, Hedysarum multijugum Maxim., Ampelopsis japonica, Pseudobulbus Cremastrae Seu Pleiones, and Paeoniae Radix Alba) that were most likely to cause skin-whitening through anti-inflammatory processes were selected. Sitogluside, the most common ingredient in the top five TCMs, inhibits melanogenesis in human melanoma cells (MNT1) and murine melanoma cells (B16F0) and decreases skin pigmentation in zebrafish. Furthermore, mechanistic research revealed that sitogluside is capable of downregulating tyrosinase (TYR) expression by inhibiting the ERK and p38 pathways and inhibiting TYR activity. These results demonstrate that network pharmacology is an effective tool for the discovery of natural compounds with skin-whitening properties and determination of their possible mechanisms. Sitogluside is a novel skin-whitening active ingredient with dual regulatory effects that inhibit TYR expression and activity.

Topical treatment for postinflammatory hyperpigmentation: a systematic review

BACKGROUND

Topical measures are the mainstay treatment for postinflammatory hyperpigmentation (PIH). Numerous studies have assessed the efficacy of topical medications for the treatment of PIH, but few have evaluated the quality of evidence supporting these topical therapies. We performed a systematic review to evaluate the evidence of topical treatments for PIH.

METHODS

We included English-language studies that evaluated topical medications for PIH. We searched PubMed, MEDLINE, and EMBASE from conception to March 29 2021. We used the modified Grading of Recommendations, Assessment, Development and Evaluation scale (GRADE) scale to assess quality of evidence.

RESULTS

Forty-seven of 1,224 studies with 1,853 subjects were included. Topical agents with high-quality studies included retinoids, hydroxy acids, corticosteroids, thiamidol, niacinamide and plant-derived products. Sunscreens with SPF30 or greater was recommended in almost every study. Common side effects included desquamation, burning, stinging, dryness, and pruritus.

CONCLUSIONS

Retinoids, hydroxy acids and broad-spectrum sunscreen were supported by the greatest number of high-quality studies. Ongoing inflammation may be subtle, especially in darker skin phenotypes. Herein, we proposed an evidence-based algorithm for PIH based on the high-quality studies. There is a need to adopt a validated outcome measure for PIH to better compare efficacy between various treatments in future studies.

Formulation and Physicochemical Evaluation of a 3% Cream Using Crude 70% Ethanolic Extract of Morus alba L. Leaves for Skin Hyperpigmentation

Background: Treatment of hyperpigmentation disorders is a challenge because of the side effects of current topical treatments. Thus, research for potent alternatives, especially of herbal origin, with comparable potency and less side effects is ongoing. Mours alba L. is a perennial plant with multiple established pharmacological effects, including antimelanogenesis effect. This effect has been demonstrated from different parts of the plant, including twigs, root barks, and leaves by measuring tyrosinase inhibition, melanin content, and melanin index, and it has been attributed to phenolic compounds such as oxyresveratrol and moracin M, to name a few. However, no study has considered formulating the total phenolic compounds from the leaves of this plant so far. Objectives: The aim of this study was to extract phenolic compounds of leaves with repeated maceration using 70% ethanol, formulate the crude extract, inspect its physicochemical stability under accelerated conditions, and assay for microbial growth and active phenolic compounds. Methods: Total phenolic compounds were extracted using 70% ethanol with repeated maceration, and then they were concentrated. The extract was then assayed for total phenolic content using Folin-Ciocalteu’s reagent. A 3% cream of this extract was manufactured, and its physicochemical parameters, microbial growth, preservative effectiveness, and total phenolic content were examined. Results: The prepared 3% cream was completely stable and homogeneous during the accelerated conditions and passed the physicochemical, total phenolic content, and microbial tests. Conclusions: The manufactured cream is a promising formulation for in vivo use as a skin lightening agent.

Tranexamic acid versus fractional carbon dioxide laser in post-acne hyperpigmentation

Post-acne hyperpigmentation is a common undesirable sequela of acne vulgaris that causes distress for many patients. This study's objective was to compare the efficacy of both low-power/low-density fractional carbon dioxide (CO₂ ) laser and tranexamic acid (TXA) microinjection on post-acne hyperpigmentation. Twenty-five post-acne hyperpigmentation patients (resistant to regular treatment for more than 6 months) were enrolled in this randomized split-face study. One side of the face was randomly assigned to low-power fractional CO₂ laser every 4 weeks, and the other side was assigned to TXA intradermal-microinjection every 2 weeks for 3 months. Efficacy was evaluated using digital photography, dermoscopy, post-acne hyperpigmentation index (PAHPI), melanin index (MI), and erythema index (EI) at baseline and 4 weeks after the last session. Both fractional CO₂ laser and TXA microinjection treatment sides showed a significant reduction in the PAHPI and MI (p < 0.001). There was statistically significant difference with better percentage of improvement regarding total dermoscopic score on the fractional CO₂ laser side than the TXA microinjections side (p < 0.009). Both fractional CO₂ laser and TXA microinjection are effective and safe treatment options for post-acne hyperpigmentation with potential superiority of fractional CO₂ laser. We also believe that dermoscopy could be helpful tool for assessment of pigmentation depth in patients on treatment by analyzing the color pattern. ClinicalTrials.govID: NCT03765021.