Prevention of melasma relapses with sunscreen combining protection against UV and short wavelengths of visible light: a prospective randomized comparative trial

Latin American consensus on the treatment of melasma

Melasma is a chronic, relapsing hyperpigmentation disorder that primarily affects photoexposed areas, occurring most frequently in adult women with darker skin phototypes. The primary factors contributing to its development include sun exposure, sex hormones (e.g., pregnancy), and genetic predisposition. Melasma is highly prevalent in Latin America, where many countries lie in intertropical zones and exhibit significant ethnic diversity because of centuries of intermixing among Native Americans, Europeans, and Sub-Saharan Africans. Nine Latin American experts formulated a DELPHI-based consensus to develop a valuable approach for treating melasma in this diverse population. After establishing an accurate diagnosis, assessing the impact on quality of life, and determining disease severity, the consensus recommends mitigating known triggers and promoting rigorous photoprotection. Active therapy should be tailored based on individual characteristics (e.g., pregnancy status, previous treatments, skin sensitivity). Treatment options include topical depigmenting agents, systemic therapies, and procedural interventions such as laser therapy, microneedling, and chemical peels. Periodic reassessment of the treatment is essential, with strategies adjusted if targeted outcomes are not achieved. Once clinical remission is attained, patients should continue using topical depigmenting agents and maintain strict photoprotection measures to prevent recurrence.

An Update on New and Existing Treatments for the Management of Melasma

Melasma is a chronic, acquired disorder of focal hypermelanosis that carries significant psychosocial impact and is challenging for both the patient and the treating practitioner to manage in the medium to long term. Multiple treatments have been explored, often in combination given the many aetiological factors involved in its pathogenesis. Therapeutic discoveries to treat melasma are a focal topic in the literature and include a range of modalities, with recent developments including updates on visible light photoprotection, non-hydroquinone depigmenting agents, oral tranexamic acid, chemical peels, and laser and energy-based device therapy for melasma. It is increasingly important yet challenging to remain up-to-date on the arsenal of treatments available for melasma to find an efficacious and well-tolerated option for our patients.

Sunscreens prescribed to patients with skin of color and/or with melasma: A survey of 221 dermatologists and dermatology residents in Spain

BACKGROUND

Dark-skinned individuals (DSI) present high rates of melasma and post-inflammatory hyperpigmentation. The use of sunscreens with mineral filters is essential for prevention and treatment. Our objective was to determine the preferences of dermatologists and dermatology residents in the prescription of sunscreens for DSI.

METHODS

An anonymous survey of attendees at an online photoprotection event held on March 31, 2022, in Spain.

RESULTS

The survey was answered by 66.6% (221/332) of the attendees: 159 dermatologists (71.9%) and 62 dermatology residents (28.1%). Respondents reported recommending the use of sunscreen to a median of 80% of DSI [interquartile range (IQR), 50-90]. Physicians reported prescribing tinted sunscreens to a median percentage of 60% (IQR, 25-90) of DSI with acne; and to a median percentage of 90% (IQR, 58-99) of DSI with melasma. The most prescribed photoprotectors to DSI with melasma were organic broad-spectrum sunscreens with antioxidants: 102/220 (46.4%) and mineral broad-spectrum sunscreens (with iron oxides): 45/220 (20.4%). In DSI with melasma or other pigmentary disorders, the most preferred features of sunscreens were as follows: sun protection factor ≥ 30: 217/221 (98.2%), UVA protection: 214/221 (96.8%), color for camouflage: 150/220 (68.2%) and mineral filters such as titanium dioxide and zinc oxide: 151/220 (68.6%) or iron oxides: 131/220 (59.5%).

LIMITATIONS

Online survey, potential inclusion bias.

CONCLUSIONS

Respondents reported to prescribe sunscreens to the majority of DSI, and tinted sunscreens for the majority of DSI with pigmentary disorders. However, the most frequently recommended sunscreens for DSI were organic broad-spectrum sunscreens with antioxidants.

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.

Guide to tinted sunscreens in skin of color

Disorders of hyperpigmentation, such as melasma and post-inflammatory hyperpigmentation, disproportionately affect skin of color and have a profound impact on quality of life. Exposure to ultraviolet light (UVL) is a well-documented factor in these disorders. However, recent studies show that visible light (VL) is a significant and underrecognized contributor to hyperpigmentation, especially in skin of color. Our objective is to review the role of VL in disorders of hyperpigmentation and that of tinted sunscreens in protecting against VL. Tinted sunscreens containing iron oxides should be recommended over nontinted sunscreens for patients prone to disorders of hyperpigmentation, as iron oxides protect against VL in addition to UVL. Tinted sunscreens are more effective than nontinted sunscreens in preventing melasma relapses and reducing hyperpigmentation, and they may also enhance the depigmenting efficacy of topical hydroquinone. In the search for an ideal tinted sunscreen for a particular patient, several factors must be considered, including a broad spectrum with adequate coverage of both UVL and VL, tint, formulation texture, active ingredients, and cost. VL is increasingly recognized as a major contributor of hyperpigmentation, and adequate treatment for disorders of hyperpigmentation should include protection against VL. Tinted sunscreens are ideal but require consideration of cosmesis, efficacy, and affordability.

Best practices in the treatment of melasma with a focus on patients with skin of color

BACKGROUND

Melasma is a chronic hypermelanosis of the skin that affects approximately 1% of the global population, predominantly affects women, and is more prevalent in skin of color. Melasma is a common driver for patients with skin of color to seek out a dermatologist for treatment, and ensuring the right approach for these patients is important because some treatments may be associated with adverse side effects. Because of the chronicity of the disease and established psychosocial and emotional impacts, there is a large need to ensure care follows the best available evidence on the treatment of patients with melasma.

OBJECTIVE

Here, we summarized current available topical treatments for melasma with considerations dermatologists should have for their patients with skin of color.

METHODS

Steering committee consensus on clinical best practices.

RESULTS

We describe a flexible and focused treatment algorithm that reflects both treatment and maintenance periods that is a consensus of our extensive clinical experience.

LIMITATIONS

Use of real-world evidence and potential for individual practice bias.

CONCLUSION

Melasma can be challenging to treat, particularly in patients with skin of color, and our recommendations for best practices for patients in the United States are an important step toward standardizing care.

Evaluation of the protection of sunscreen products against long wavelength ultraviolet A1 and visible light-induced biological effects

BACKGROUND

Long wavelength ultraviolet-A1 in combination with visible light induces hyperpigmentation, particularly in dark-skin phototypes. This study evaluated the efficacy of four sunscreen formulations in protecting against VL + UVA1 (370-700 nm).

METHODS

The test products (A-D) were applied to the back of 12 volunteers, then irradiated with 320 J/cm2 VL + UVA1 (3.5% UVA1 [370-400 nm]). Immediately after irradiation, and at Days 1, 7, and 14, erythema and pigmentation were assessed by investigator global assessment (IGA), colorimetry (Δa* and ΔITA) and diffuse reflectance spectroscopy (DRS)-measured relative dyschromia (area under the curve AUC). Control areas were irradiated without sunscreen.

RESULTS

Product D, containing titanium dioxide 11%, iron oxides 1%, and antioxidants, provided the highest and most consistent protection. Compared with unprotected irradiated control, it had statistically significantly less erythema on IGA, DRS (Δoxyhemoglobin), and colorimetry (Δa*) at Day 0; less pigmentation on IGA at all time points, on DRS (relative dyschromia) at Days 7 and 14, and on colorimetry (ΔITA) at Day 0. Product B, containing zinc oxide 12% plus organic UV filters, iron oxides 4%, and antioxidants, also showed some efficacy.

CONCLUSION

Of the sunscreens tested, the tinted products provided better protection against VL + UVA1 than the non-tinted products. Since the product with 1% iron oxides was superior to the product with 4% iron oxides, further studies are needed to evaluate whether iron oxide content correlates with better protection.

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.

The Emerging Role of Visible Light in Melanocyte Biology and Skin Pigmentary Disorders: Friend or Foe?

Electromagnetic radiation, notably visible light (VL), has complicated effects on human skin, particularly pigmentation, which have been largely overlooked. In this review, we discuss the photobiological mechanisms, pathological effects, clinical applications and therapeutic strategies of VL at varying wavelengths on melanocyte biology and skin pigmentary disorders. Different VL wavelengths may impose positive or negative effects, depending on their interactions with specific chromophores, photoaging, ROS production, circadian rhythm and other photon-mediated reactions. Further in vivo and in vitro studies are required to establish the pathologic mechanisms and application principles of VL in pigmentary disorders, as well as optimal photoprotection with coverage against VL wavelengths.

Use of Picosecond Laser for Melasma Treatment: A Narrative Review

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

Sun exposure behaviours as a compromise to paradoxical injunctions: Insight from a worldwide survey

BACKGROUND

Behavioural interventions can improve attitudes towards sun protection but the impact remains inconsistent worldwide.

OBJECTIVE

To assess awareness of and attitudes towards the multiple facets of sun exposure and suggest ways to improve prevention from overexposure to the sun in all geographical zones and multiple skin types.

METHODS

Online survey was conducted from 28 September to 18 October 2021. Study population was selected from the Ipsos online Panel (3,540,000 panellists), aged ≥18 years, from 17 countries around the five continents. Demographics, sun-exposure habits and practices, understanding of risks and information on phototypes were documented and analysed using descriptive statistics.

RESULTS

Eighty-eight per cent of participants knew that sunlight can cause skin health problems (90% phototypes I-II, 82% phototypes V-VI, >90% in American and European countries, 72% in Asia and 85% in Africa). Eighty-five per cent used some form of protection against sunlight, predominantly: Seeking shade (77%), avoiding the midday sun (66%), facial application of sunscreen (60%) and wearing protective clothing (44%). The perception of sunlight itself is positive ('it gives energy' for 82%; 'tanned skin looks attractive' for 72%), although less in Asian countries and among individuals with dark skin phototypes. Eighty-three per cent reported having experienced sunburn, mainly in Australia, Canada, USA, Germany, France and Russia, and among individuals with dark skin phototypes. Only 12% systematically/often used all types of protection during exposure to the sun and 23% believed it is safe to go out in the sun with no protection when their skin is already tanned. From 13% (skin phototype I) to 26% (phototype VI) reported not using any form of protection against the sun. Knowledge and habits were significantly superior among people who are accustomed to seeing a dermatologist for a complete skin exam.

CONCLUSIONS

Dermatologists could play a crucial role in relaying novel prevention messages, more finely tailored to specific risks, populations and areas of the world.

Efficacy and safety of a novel triple combination cream compared to Kligman's trio for melasma: A 24-week double-blind prospective randomized controlled trial

BACKGROUND

Kligman's trio (KT), combining hydroquinone, retinoic acid and corticosteroid, is considered as the gold standard treatment of melasma. Its efficacy has never been matched before, but it is tempered by frequent adverse effects.

OBJECTIVE

To assess the efficacy and tolerance of a New Trio (NT) combination with isobutylamido-thiazolyl-resorcinol, retinoic acid and cortosteroid compared to KT.

METHODS

We conducted a 24-week monocentric trial, randomized, double-blind, controlled versus KT, with 40 melasma patients. NT and KT were applied for 12 weeks and associated with the same sunscreen applied for 24 weeks. The primary endpoint was the modified Melasma Area Severity Index (mMASI) at 12 weeks. Patient quality of life was investigated using MelasQoL.

RESULTS

After 12 weeks, KT and NT groups both demonstrated a significant improvement in mMASI, respectively -2.84 (SE 0.69, p < 0.0002) and -4.33 (SE 0.71, p < 0.0001). The mean difference between the two groups was -1.49 (IC 95% -3.52 to 0.54, p = 0.14). MelasQoL improvement was -6.66 (SE 3.29, p = 0.0515) with KT and -12.57 (SE 3.29, p = 0.0006) with NT.

CONCLUSION

The NT combination appears to be an effective treatment option for treating melasma and could be considered as a well-tolerated alternative to KT.

Topical and Systemic Therapies in Melasma: A Systematic Review

Introduction

Melasma is an acquired disorder, which presents with well-demarcated, brown-colored hyperpigmented macules, commonly involving the sun-exposed areas such as the face. It is a chronic and distressing condition, affecting the patients' quality of life, and has been conventionally treated with "first-line" agents including hydroquinone (HQ) alone or as a part of a triple combination cream (TCC), while "second-line" options include chemical peels, and third line options include laser therapy.

Materials and Methods

A systematic search was performed for all topical and systemic treatments for melasma up till May 4, 2021, using the PubMed and EMBASE databases, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. The search terms "melasma" and "treatment" were used to search for the relevant articles on both these databases, and a total of 4020 articles were identified. After removing the duplicate entries and screening the titles, abstracts, and full-text articles, we identified 174 randomized controlled trials (RCTs) or controlled clinical trials.

Results

Based on our review, HQ, TCCs, sunscreens, kojic acid (KA), and azelaic acid receive grade A recommendation. Further large-scale studies are required to clearly establish the efficacy of topical vitamin C, resorcinol, and topical tranexamic acid (TXA). Several newer topical agents may play a role only as an add-on or second-line drugs or as maintenance therapy. Oral TXA has a strong recommendation, provided there are no contraindications. Procyanidins, Polypodium leucotomos (PL), and even synbiotics may be taken as adjuncts.

Discussion

Several newer topical and systemic agents with multimodal mechanisms of action have now become available, and the balance seems to be tipping in favor of these innovative modalities. However, it is worth mentioning that the choice of agent should be individualized and subject to availability in a particular country.

Broad-spectrum sunscreens containing the TriAsorB™ filter: In vitro photoprotection and clinical evaluation of blue light-induced skin pigmentation

BACKGROUND

Blue light (BL), particularly high-energy visible (HEV) light (400-450 nm), can cause skin damage and pigmentation. Therefore, effective sunscreens should offer photoprotection beyond ultraviolet (UV) radiation to also prevent or limit BL-induced cutaneous effects.

OBJECTIVES

To evaluate the in vitro BL photostability and photoprotection properties of nine sunscreens containing the broad-spectrum UV/BL phenylene bis-diphenyltriazine (PBDT or TriAsorB™) filter, together with three other organic UV filters, and to assess the in vivo photoprotection level provided by two of these products against BL-induced skin pigmentation.

METHODS

In vitro BL photostability and photoprotection factors, comprising the percentage of BL radiation stopped by the product (%BL) and the critical wavelength extended to BL (BL-CW), were determined by spectrophotometry. The in vivo photoprotection provided by two representative sunscreens (i.e. similar formulations, one non-tinted and one tinted) was assessed in two open randomized studies (20 and 16 women, respectively) after exposure of two test areas (with and without sunscreen) on the back of each subject to a 412-nm irradiation dose at 50 J/cm2 , using instrumental and clinical measurements of skin pigmentation. The percentage sunscreen photoprotective effectiveness (%PPE) was calculated by comparing intrasubject post-exposure pigmentation changes between the with and without sunscreen test areas.

RESULTS

In vitro, the nine PBDT-containing products were highly photostable and had a BL-CW ≥385 nm and a %BL ≥30% (range: 30%-50%), thus allowing effective BL photoprotection. In vivo, both representative sunscreens prevented BL-induced immediate skin pigmentation (1 and 24 h post-exposure) with %PPE values ranging from 50.7% to 75.5% for colorimetric assessments (p < 0.001) and from 31.2% to 72.7% for visual scores (p ≤ 0.001).

CONCLUSIONS

All PBDT-containing sunscreens were considered effective at absorbing BL radiation in vitro. The two representative broad-spectrum sunscreens tested in subjects significantly reduced BL-induced immediate skin pigmentation following single exposure to monochromatic BL radiation.

Cutaneous interaction with visible light: What do we know?

Visible light has been used therapeutically in dermatology for years for a variety of cosmetic and medical indications, including skin rejuvenation and the treatment of inflammatory and neoplastic conditions, among others. Until recently, visible light was thought to be relatively inert compared to its spectral neighbors, ultraviolet and infrared radiation. However, recent literature has described the ability of visible light to cause erythema in light skin and pigmentary changes in individuals with darker skin types. Concern surrounding its potentially damaging cutaneous effects has been raised in both the medical community and social media outlets. In this article, we provide an evidenced-based review describing what is currently known about visible light, focusing on its role in dermatologic diseases including disorders of hyperpigmentation such as melasma and postinflammatory hyperpigmentation.

[Skin aging exposome]

The skin is a barrier organ and thus exposed to environmental factors from birth, which essentially determine skin aging. In order to describe and understand this complex process exactly, we applied the concept of the "exposome" to the environmentally induced skin aging process. In this review, we summarize current knowledge on the skin aging exposome. In this context, we characterize the most important exposomal factors, address their relative importance for skin aging and also the relevance of their mutual interactions. Finally, we discuss the clinical consequences resulting from this concept for an effective prevention of skin aging.

Sunscreens: Misconceptions and Misinformation

Over the past 70 years, sunscreens have evolved from beach products designed to prevent sunburn to more cosmetically elegant skincare products intended to protect against multiple long-term adverse consequences of characteristically low-intensity daily UV and visible light exposure. Sunscreen testing and labeling intended to quantify such protection are unfortunately often misunderstood by users and have also led to illegal misleading and potentially dangerous industry practices. Changes in regulatory requirements, better policing, and more informative sunscreen labeling would benefit users and their physician advisors.

Impact of blue light on skin pigmentation in patients with melasma

BACKGROUND

The difference in skin pigmentation induced by blue light between melasma patients and healthy people has not been reported. This study aimed to explore the impact of different doses of blue light irradiation on the pigmentation of the skin of non-exposed areas in female melasma patients with III-IV-type skin and healthy women.

MATERIALS AND METHODS

This observational study enrolled patients with melasma and healthy people at the First Affiliated Hospital of Kunming Medical University between January and April 2021. The outcomes were the degree of pigmentation, ΔL*, and ΔITA* values.

RESULTS

Forty-two (21/group) participants were enrolled. After irradiation with different doses of blue light, different degrees of pigmentation could be observed in the irradiated area of the skin of female melasma patients and healthy women. The △L* and △ITA* values in the irradiated area of the skin of healthy women were higher than in female melasma patients after blue light irradiation at 20 J/cm2 (p < 0.05). There were no significant differences in the pigmentation scores, △L* values, and △ITA* values in the irradiated areas of skin at different time points after irradiation with the other doses of blue light (p > 0.05).

CONCLUSION

Blue light at 20 J/cm2 induced a smaller change in pigmentation in melasma patients than in healthy women, but the effect of blue light at 40-80 J/cm2 was similar.

Photoaging and Topical Rejuvenation

Photoaging is a complex process of skin changes associated with chronic ultraviolet exposure. Prevention with photoprotection and treatment with topical retinoids are the core components of a topical antiaging regimen. Other topicals such as hydroquinone, vitamin C, niacinamide, and alpha hydroxyl acid can be added based on specific concerns. However, caution must be used with some of these products as the stability and absorption are major considerations. A simple topical regimen will reduce irritability and enhance compliance.

New Mechanistic Insights of Melasma

Melasma is a common acquired disorder of pigmentation that negatively impacts quality of life. Present treatments show poor therapeutic effect with frequent recurrence. This in large part is due to the currently limited understanding of the disease's etiology. It is urgent to elucidate the pathogenesis of melasma to further the discovery of new therapeutic strategies. Recent studies show that melasma is triggered or aggravated by a variety of factors, including genetic susceptibility, ultraviolet radiation, and sex hormone dysregulation. Ultraviolet B radiation upregulates the expression of several melanocyte-specific genes and stimulates the release of key factors that participate in the synthesis of melanin. There is a significant increase in melanin in both the epidermal and dermal layers of affected skin, possibly due to abnormalities in crosstalk between the melanocytes and other cells. Melanogenesis is regulated through various signaling networks including the Wnt/β-catenin, PI3K/Akt, cAMP/PKA, and SCF/c-kit-mediated signaling pathways. In addition, inflammatory mediators, oxidative stress, neuroactive molecules, sebocytes, etc, have also been proved to be related to the pathogenesis of melasma. This review provides a comprehensive update on the current understanding of the pathogenesis of melasma.

Highlighting nuances of blue light phototherapy: Mechanisms and safety considerations

The efficacy of blue light therapy in dermatology relies on numerous clinical studies. The safety remains a topic of controversy, where potentially deleterious effects were derived from in vitro rather than in vivo experiments. The objectives of this work were (1) to highlight the nuances behind "colors" of blue light, light propagation in tissue and the plurality of modes of action; and (2) to rigorously analyze studies on humans reporting both clinical and histological data from skin biopsies with focus on DNA damage, proliferation, apoptosis, oxidative stress, impact on collagen, elastin, immune cells, and pigmentation. We conclude that blue light therapy is safe for human skin. It induces intriguing skin pigmentation, in part mediated by photoreceptor Opsin-3, which might have a photoprotective effect against ultraviolet irradiation. Future research needs to unravel photochemical reactions and the most effective and safe parameters of blue light in dermatology.

Melasma: The need for tailored photoprotection to improve clinical outcomes

BACKGROUND/PURPOSE

Melasma is a frequent photoexacerbated hyperpigmentary disorder, which can significantly impact on the quality of life. We sought to review the pathogenesis of melasma, and the role of photoprotection in the prevention and treatment of this disorder.

METHODS

We conducted a narrative review of the literature. We performed literature searches with PubMed from January 1990 to December 2021 using the keywords "melasma," "pathogenesis," "ultraviolet radiation," "visible light," "photoprotection," and "sunscreens."

RESULTS

The physiopathology of melasma includes a complex interaction between genetics, sex hormones, and sun exposure. Visible light, in particular high-energy visible light (HEVL), and long-wave UVA (UVA1) play a key role in melasma pathophysiology, and recent research suggests that melasma shares many features with photoaging disorders. Melasma disproportionately affects dark-skinned individuals. Some 30% to 50% of South Americans and Asians, among other ethnicities, can present with melasma. Dark-skinned patients take fewer photoprotective measures. Also, the majority of melasma patients do not adequately follow photoprotection recommendations, including the application of sunscreen. Intensive use of a broad-spectrum sunscreen can prevent melasma in high-risk individuals, can lessen melasma severity (associated or not with depigmenting agents), and can reduce relapses.

CONCLUSIONS

Due to the physiopathology of melasma, sunscreens should be broad-spectrum with high sun protection factor, and provide high protection against UVA1 and VL. Sunscreens should be cosmetically acceptable and leave no white residue. Tinted sunscreens are an excellent choice, as pigments can protect from HEVL and UVA1, and may provide camouflage, but they must offer colors that match the skin tone of each patient.

Update on Melasma-Part II: Treatment

Melasma is a prevalent chronic relapsing pigmentary disorder that affects photoexposed areas, especially in women of childbearing age. Although there is currently no curative treatment available for melasma, this manuscript critically reviews the knowledge regarding photoprotection, topical and oral therapies, and procedures such as peelings, laser, and microneedling that represent the main strategies for control and prevention of this disease. As the pathogenesis of melasma is not entirely understood, there are prospects for the development of new therapeutic strategies that might act on the pathways that promote sustained pigmentation rather than merely decreasing melanin synthesis and removing melanin from the epidermis.

The Damaging Effects of Long UVA (UVA1) Rays: A Major Challenge to Preserve Skin Health and Integrity

Within solar ultraviolet (UV) light, the longest UVA1 wavelengths, with significant and relatively constant levels all year round and large penetration properties, produce effects in all cutaneous layers. Their effects, mediated by numerous endogenous chromophores, primarily involve the generation of reactive oxygen species (ROS). The resulting oxidative stress is the major mode of action of UVA1, responsible for lipid peroxidation, protein carbonylation, DNA lesions and subsequent intracellular signaling cascades. These molecular changes lead to mutations, apoptosis, dermis remodeling, inflammatory reactions and abnormal immune responses. The altered biological functions contribute to clinical consequences such as hyperpigmentation, inflammation, photoimmunosuppression, sun allergies, photoaging and photocancers. Such harmful impacts have also been reported after the use of UVA1 phototherapy or tanning beds. Furthermore, other external aggressors, such as pollutants and visible light (Vis), were shown to induce independent, cumulative and synergistic effects with UVA1 rays. In this review, we synthetize the biological and clinical effects of UVA1 and the complementary effects of UVA1 with pollutants or Vis. The identified deleterious biological impact of UVA1 contributing to clinical consequences, combined with the predominance of UVA1 rays in solar UV radiation, constitute a solid rational for the need for a broad photoprotection, including UVA1 up to 400 nm.

Is the Technology Era Aging You? A Review of the Physiologic and Psychologic Toll of Technology Use

BACKGROUND

Technology use is at an all-time high and its potential impact on psychological and physiologic health should be explored.

OBJECTIVE

The objective of this narrative review was to identify the role of technology use on health and well-being.

MATERIALS AND METHODS

Authors performed a review of PubMed and publications of the World Health Organization, Department of Defense, and Centers for Disease Control and Prevention to determine the impact of technology regarding electromagnetic radiation (EM), posture and mobility, sleep disturbance, and psychological stress and well-being.

RESULTS

Studies on the impact of EM were conflicting, with about 45% reporting negative consequences and 55% reporting no effect. Radiofrequency EM (RF-EM) may more significantly affect fibroblasts and immature cells. Device use was implicated in worsening cognitive focus, imbalance, and sleep. Social media use affects self-esteem and mental health and is associated with up to 33% presence of addiction. Effects seem to be dose related and more pronounced in younger ages.

CONCLUSION

Technology use significantly affects sleep, mental health, and cognitive function. Seeking psychological help, limiting social media use, and reducing use before sleep may partially mitigate these effects. The impact of EM is undetermined, but the WHO lists RF-EM as a potential carcinogen.

Medical therapies for Melasma

Melasma is a common malady affecting all races with a higher incidence in Hispanics, Middle Eastern, Asians and African origin females (Fitzpatrick skin phototypes III-V). Women are affected much more often than men. Melasma remains a significant cause of cosmetic morbidity and psychosocial embarrassment affecting quality of life necessitating effective and reliable treatment. Unfortunately, treatment remains unsatisfactory due to limited efficacy, adverse effects and relapses after stopping treatment. Although chemical peels, laser and light therapies and dermabrasion may have utility, the evidence available for their efficacy is limited and they often cause post inflammatory hyperpigmentation particularly in individuals with darker skin types. Medical therapies remain mainstay in the management of melasma. The triple combination, hydroquinone 4%, tretinoin 0.05% and fluocinolone acetonide 0.01% (Triluma, Galderma, Ft. Worth Texas, often modified incorporating different corticosteroids) remains the only US FDA approved treatment for melasma and is the gold standard due its demonstrated efficacy across ethnicities. Oral tranexamic acid alone or in combination with other modalities has also shown significant efficacy. Several cosmeceuticals and botanical extracts used as skin lightening agents have been demonstrated to be useful. Physical sunscreens containing zinc oxide, iron oxide, titanium dioxide, and silicones provide photoprotective and camouflage effect. We propose that a multimodality approach to the treatment of melasma is the most effective treatment approach. This review is focused on the medical therapies for melasma.

The protective effect of a novel sunscreen against blue light

BACKGROUND AND OBJECTIVE

Premature skin ageing, and skin hyperpigmentation are influenced by exogenous factors, such as ultraviolet radiation and blue light. In this study, we assess the protective effect of a sunscreen (TDF^® Blu Voile Sunscreen) in protecting the skin against the harmful effects of blue light irradiation in vivo and through the in situ quantitative and qualitative evaluation of protein carbonylation in human skin explants.

METHODOLOGY

The protective effect of the test product against blue light was first evaluated ex vivo on human skin explants. The treated and non-treated explants were exposed to 14 J/cm² of blue light 460 nm following which the protein carbonylation was evaluated by in situ epifluorescence imaging and separation by high-resolution gel electrophoresis. To determine whether the test product could also protect against the immediate and persistent pigmenting effect of blue light, two randomized in vivo studies were conducted, which included respectively 17 subjects with a skin phototype of IV and V (Fitzpatrick classification) and 22 subjects with a skin phototype of IV, V, and VI (Fitzpatrick classification). The duration of the study for each subject was 2 days (D1 and D2) for immediate observations and 5 days (D1-D5) for persistent observations. Specific zones on the subjects' back were either left non-treated or treated with the test product and were then exposed to a unique dose of blue light 415 nm. The onset of pigmentation between the treated and exposed zones was then assessed relative to the non-exposed treated zone through colorimetric measurements of the Individual Typology Angle (ITA^o ).

RESULTS

Human skin explants treated with test product showed significantly lower levels of accumulated carbonylated proteins, with a protection of 82%, following exposure to blue light 460 nm. Findings of the in vivo studies also indicated that the test product presented significantly better protective efficacy against immediate and persistent pigmentation induced by blue light 415 nm.

CONCLUSION

Hence, it can be concluded that the test product can protect against the oxidative stress as well as the immediate and persistent pigmentation induced by blue light.

Efficacy of low-fluence 1,064 nm Q-switched Nd: YAG laser for the treatment of melasma:a meta-analysis and systematic review

BACKGROUND

Melasma is considered as a type of acquired facial pigmentary disorder that is challenging to treat. Low-fluence 1,064 nm Q-switched Nd: YAG laser (LQSNY) has clinical benefits against melasma, however there are some disputes.

OBJECTIVE

To explore these contentious views, we conducted a meta-analysis and systematic review to evaluate the efficacy and safety of LQSNY monotherapy and combined therapy for the treatment of melasma.

METHODS

The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for relevant articles from inception to July 2021. The resulting data were analyzed using the Review Manager 5.3 software.

RESULTS

Twelve eligible studies comprising 358 patients were included. No significant differences in melasma area and severity index (MASI) were observed between the LQSNY and drug groups (mean difference (MD):-0.26, 95% confidence interval (CI):-1.16-0.64, P=0.57). We found that combination therapy with LQSNY and drugs had a greater MASI improvement compared to LQSNY therapy alone (MD: 1.78, 95% CI 0.93-2.63, P<0.0001), nevertheless, no statistically significant results were found in melanin index (MI) and self-assessment. The melasma improvement was similar when using LQSNY alone and LQSNY combined with other lasers in terms of RMASI (MD 0.05, 95% CI:-0.61, 0.70, P=0.56). Compared to intense pulsed light (IPL) alone, LQSNY with IPL provided an added benefit for melasma severity (MD:3.23, 95%CI:0.65-5.81, P=0.01).

CONCLUSION

LQSNY can be applied as an alternative treatment for drug intolerance. Combination therapy with LQSNY and drugs or other lasers may have pleasantly surprising efficacy, but numerous studies are still needed to verify this.

Effects of visible light on mechanisms of skin photoaging

Human skin is not only affected by ultraviolet radiation but also by visible light wavelengths emitted by sunlight, electronic devices, and light emitting diodes. Similar to the ultraviolet radiation, visible light has been implicated in photoaging. In this review, the effects of blue light, yellow light, red light, and broad visible light are discussed in relation with photoaging. Different visible light wavelengths likely contribute beneficial and deleterious effects on photoaging by way of interaction with specific photoreceptors, ROS production, and other photon-mediated reactions. Further in vivo studies are needed to determine the mechanism and action spectrum of photoaging in humans, as well as optimal photoprotection with coverage against visible light wavelengths.

An update on cosmetic procedures in people of color. Part 1: Scientific background, assessment, preprocedure preparation

Increased life expectancy, focus on appearance, and readily available and accessible cosmetic procedures have served to drive an increase in the number of nonsurgical cosmetic procedures performed in the last 20 years. Demographic shifts in the United States, with increases in diverse populations that seek nonsurgical cosmetic procedures, have resulted in the need for a better understanding of cultural preferences as well as structural and biological differences in the skin of people of color (POC). Although many advances in the form of cosmeceuticals, cosmetics, and photoprotection have been made to address the aesthetic needs of and minimize complications in POC, nonsurgical cosmetic procedures are required to address common aesthetic concerns. Gaps remain in the education of dermatologists regarding the appropriate selection and execution of nonsurgical cosmetic procedures in POC. This educational initiative will facilitate a favorable outcome and optimal cosmetic results for POC.

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.

Self-applied topical interventions for melasma: a systematic review and meta-analysis of data from randomized, investigator-blinded clinical trials

BACKGROUND

Melasma is a frequent dermatological condition. Although its relevance as a skin condition is primarily of cosmetic nature, it may affect the patients' well-being and quality of life. A broad range of treatment options is available, which makes it difficult to choose the most appropriate treatment.

OBJECTIVES

To summarise and critically appraise evidence from investigator-blinded RCTs on the efficacy and safety of self-applied topical interventions for melasma.

METHODS

We systematically searched MEDLINE and Cochrane CENTRAL for RCTs on topical, self-administered interventions for patients diagnosed with melasma. Eligibility was limited to RCTs that explicitly stated in their methods section (1) how they generated the random allocation sequence, and (2) that the study outcome assessor was blinded towards the participants' group allocation. Outcomes of interest included evaluator-assessed clinical scores (e.g., melasma area and severity index, MASI), quality of life, and patient-reported outcomes as well as safety outcomes. The study findings were meta-analysed, pooling data from studies on the same comparisons, if this was possible. We assessed confidence in the effect estimates using the GRADE approach.

RESULTS

Our searches yielded 1,078 hits. We included 36 studies reporting on 47 different comparisons of interventions. These included medical treatments such as 'triple combination cream' (TCC), over-the-counter cosmetic and herbal products, as well as sun creams covering different light spectra. Pooling data was possible for only two comparisons (topical tranexamic acid (TXA) vs. hydroquinone (HQ) and cysteamine vs. placebo). Direct comparisons were available for a variety of interventions; however, the reported outcomes varied largely. Overall, our confidence in the effect estimates ranged from very low to high.

CONCLUSION

Our findings indicate that TCC and its individual components HQ and tretinoin are effective in lightening melasma. Besides these established self-applied treatment options, we identified further medical as well as promising cosmetic and herbal product treatment approaches. Furthermore, evidence suggests that using broad-spectrum sunscreen covering both the visible and UV-light spectrum enhances the treatment efficacy of HQ. However, with mostly small RCTs comparing treatments directly, using a broad range of outcomes, further research is needed to draw conclusions about which treatment is most effective.

[Sunscreens of the future: challenges and opportunities]

Sunscreens provide excellent protection against erythema and against chronic damage such as photoaging and skin cancer. Today's challenges concern safety of the products and improved methods for standardizing the evaluation of their efficacy. Other important topics are the further development of sunscreen products, as well as personalization of use. Personalized sun protection based on the phenotype, the genetic profiles and moreover the skin's microbiome - all linked to the identification of certain consumer susceptibility factors - is an exciting new area of research. In particular, the expansion with innovative topical agents such as DNA repair liposomes in improved galenic formulations with UV filters tailored to the skin phototype and new topical antioxidants could in future provide even more comprehensive sun protection. New antioxidants and other agents such as nicotinamide could increase systemic photoprevention. Sustainability will also be an important aspect to protect consumers, but also the environment (i.e. especially marine wildlife) from toxic effects of sunscreens.

A new in vitro method to predict in vivo photoprotection of skin hyperpigmentation induced by visible light

Background

Ultraviolet radiation is the main cause of skin pigmentation, but more recently visible light has been shown to be an important contributor especially in melano‐competent subjects. Photoprotection from visible light can improve several hyperpigmentation disorders. Recently, a visible light photoprotection assessment method has been proposed based on in vivo pigmentation; the visible light photoprotection factor (VL‐PF) is determined by assessment of the change in colorimetry parameter ITA over several days measured using a chromameter. Although in vivo methods remain the most representative of real life, in vitro methods are more suited to screening sunscreen formulations.

Objective

The aim of this study was to evaluate the correlation between in vivo and in vitro methods in assessing protection against visible light induced pigmentation.

Methods

We first analysed the in vitro protective properties of the 10 commercially available sunscreens using transmission measurements in the visible spectrum. Then, we performed a monocentric, double‐blind, randomized controlled study with intra‐individual comparisons in 20 healthy subjects and measure the VL‐PF in vivo of those sunscreens. The correlation between the VL‐PF and the percentage of blocked light was evaluated using the coefficient of determination R².

Results

A strong significant correlation was demonstrated between in vivo visible light protection factor and in vitro transmittance measurements, with the highest correlation factor at 420 nm and in the spectrum covering from 400 to 469 nm.

Conclusion

Transmittance measurements were found to be a good predictive tool to evaluate sunscreen visible light photoprotection efficacy and could be used to select formulations for final in vivo testing.

Photoprotection by clothing: A review

Clothing is recognized by leading health agencies as a primary method to protect against the harmful effects of photodamage caused by ultraviolet (UV) radiation and visible light. The photoprotective capacity of clothing is commonly measured as the ultraviolet protective factor (UPF). While the technology driving photoprotective clothing has been well-established, there continues to be efforts to discover new materials to improve the UPF of clothing. Here, we show increased Google searches for photoprotective clothing over the last decade, suggesting a high level of public interest in photoprotective clothing. In addition, we investigate the frequency of UPF-graded photoprotective clothing sold by large retail stores featured in Fortune 1000. We review factors that alter the UPF of clothing and describe emerging textile technologies used to increase clothing's photoprotective capacity. Finally, we compare how photoprotective clothing is regulated among different countries, the importance of photoprotective clothing in occupational health, and research in visible light and clothing photoprotection.

PHOTOPROTECTION FOR ALL: CURRENT GAPS AND OPPORTUNITIES

The effects of solar radiation on human skin differ based on skin phototype, the presence or absence of photodermatoses, biological capacity to repair DNA damage, wavelength, intensity of sun exposure, geographic latitude, and other factors, underscoring the need for a more tailored approach to photoprotection. To date, the focus of photoprotection guidelines has been to prevent sunburn and DNA damage induced by ultraviolet (UV) radiation, both UVB and UVA; however, several recent studies have shown that visible light (VL) also generates reactive oxygen and nitrogen species that can contribute to skin damage and pigmentation on the skin, particularly in people of color. Therefore, dark-skinned individuals, while naturally better protected against UVB radiation by virtue of high eumelanin content in melanocytes, may need additional protection from VL-induced skin damage. The current options for photoprotection products need to expand, and potential strategies against VL include the addition of iron oxide, titanium dioxide, and biologically relevant antioxidants to sunscreen formulations, as well as supplementation with orally active antioxidants.

Photoprotection for skin of all color: Consensus and clinical guidance from an expert panel

The negative effects of sun exposure have become better accepted among health care professionals and the lay public over recent decades. Most attention has been focused on the effects of UV light, particularly UVB wavelengths (290-320 nm). Accordingly, products to protect skin from sunlight-associated harm (sunscreens) have been developed to minimize UVB exposure. The effects of longer wavelengths, including UVA (320-400 nm) and visible light (VL, 400-700 nm), are increasingly appreciated. VL accounts for approximately half of the solar radiation that reaches the earth's surface and understanding of its effects on the skin is improving. Studies have shown that VL can induce hyperpigmentation in individuals with dark skin types (Fitzpatrick skin types IV-VI). In addition, VL can contribute to the exacerbation of pigmentary disorders, including melasma. Because these findings are relatively new, there are gaps in understanding the needs for photoprotection and guidance for clinicians. A panel of dermatologists and photobiologists was convened to develop consensus recommendations and clinical guidance about sunscreen use relevant to the current understanding of risks associated with sun exposure using a modified Delphi method.

Lasers, lights, and compounds for melasma in aesthetics

Melasma is a chronic and relapsing skin condition. Although melasma is usually asymptomatic, it can be associated with immense psychosocial stress and greatly impact a patient's quality of life. Over the years, many different treatments have been used, ranging from daily photoprotection, topical lightening creams, and oral agents to laser and light-based therapies; however, efficacy is often limited with such treatments, and there is currently no effective modality to prevent recurrence. Although treatment strategies had originally centered on the use of hydroquinone, newer modalities now include oral tranexamic acid and lasers. We examined previous and ongoing debates related to melasma treatments and have reviewed the current efficacy and safety of available treatments. Critical components essential to the successful management of melasma are the setting of patient expectations and assurance of treatment compliance.

The Application of Skin Care Product in Melasma Treatment

Melasma is an acquired and chronic hyperpigmentation disorder which is recognized as one of the most psychologically distressing and difficult to cure forms of skin hyperpigmentation. It is associated with substantial quality of life impairments. Treatments of melasma include local application, oral medication, physical laser therapy and program combination therapy. However, routine treatment usually leads to the damage of skin barrier function, resulting in adverse reactions such as erythema, pruritus, post-inflammatory pigmentation and even scar. Skin care products contain a variety of active ingredients, which are widely concerned by cosmetic dermatologists because of high safety, good tolerance and the effect of improving the damaged skin barrier. Using skin care products alone or in combination with routine treatment not only can improve the curative effect for melasma, reduce side effects and recurrence rate, but also improve patient satisfaction. This article mainly describes the application of skin care products in the treatment of melasma.

Photoprotection of the Skin from Visible Light‒Induced Pigmentation: Current Testing Methods and Proposed Harmonization

Visible light (VL) can induce pigmentary alterations, especially in dark-skinned individuals, and exacerbate photodermatoses and pigmentary disorders. Currently, there is no standardized method for assessing sunscreen protection against VL. On the basis of a critical review of published in vitro and in vivo methods, a VL photoprotection assessment method based on pigmentation is proposed.

Clinical and biological impact of the exposome on the skin

The skin exposome is defined as the totality of environmental exposures over the life course that can induce or modify various skin conditions. Here, we review the impact on the skin of solar exposure, air pollution, hormones, nutrition and psychological factors. Photoageing, photocarcinogenesis and pigmentary changes are well-established consequences of chronic exposure of the skin to solar radiation. Exposure to traffic-related air pollution contributes to skin ageing. Particulate matter and nitrogen dioxide cause skin pigmentation/lentigines, while ozone causes wrinkles and has an impact on atopic eczema. Human skin is a major target of hormones, and they exhibit a wide range of biological activities on the skin. Hormones decline with advancing age influencing skin ageing. Nutrition has an impact on numerous biochemical processes, including oxidation, inflammation and glycation, which may result in clinical effects, including modification of the course of skin ageing and photoageing. Stress and lack of sleep are known to contribute to a pro-inflammatory state, which, in turn, affects the integrity of extracellular matrix proteins, in particular collagen. Hormone dysregulation, malnutrition and stress may contribute to inflammatory skin disorders, such as atopic dermatitis, psoriasis, acne and rosacea.

Photoprotection according to skin phototype and dermatoses: practical recommendations from an expert panel

Increasing evidence on the impact of the different wavelengths of sunlight on the skin demonstrates the need for tailored recommendations of sunscreen according to skin phototype and dermatoses, which is now possible due to advances in the filters and formulations of sunscreens. A selective literature search was performed by an international expert panel, focusing on the type of sunscreen to recommend for photoaging, skin cancers, photodermatoses, pigmentary disorders and skin inflammatory disorders. Protection against ultraviolet (UV)B is especially important for light skin as there is a high risk of sunburn, DNA damage and skin cancers. Darker skin may be naturally better protected against UVB but is more prone to hyperpigmentation induced by visible light (VL) and UVA. Protection against UVA, VL and infrared A can be helpful for all skin phototypes as they penetrate deeply and cause photoaging. Long‐wave UVA1 plays a critical role in pigmentation, photoaging, skin cancer, DNA damage and photodermatoses. Adapting the formulation and texture of the sunscreen to the type of skin and dermatoses is also essential. Practical recommendations on the type of sunscreen to prescribe are provided to support the clinician in daily practice.

Daily photoprotection to prevent photoaging

BACKGROUND

Extrinsic skin aging or photoaging was previously thought to be almost exclusively due to solar ultraviolet (UV) radiation. However, recent literature has described other contributing factors and clarification is thus required as to what extent and what type of daily photoprotection is needed to mitigate extrinsic skin aging.

METHODS

We reviewed the existing scientific evidence on daily photoprotection, and specific requirements at the product level, to prevent extrinsic skin aging. We critically reviewed the existing evidence on potential ecological and toxicological risks which might be associated with daily photoprotection.

RESULTS

Evidence shows that broad protection against the entire solar range of UVB, UVA, UVA1, visible light, and short infrared (IRA) is required to prevent extrinsic aging. Other exposome factors, such as air pollution and smoking, also contribute to skin aging. Daily broad-spectrum sunscreen photoprotection should thus contain antioxidant ingredients for additional benefits against UV, IRA, and pollution-induced oxidative stress as well as anti-aging active ingredients to provide clinical benefits against skin aging signs, such as wrinkles and dark spots. Broad-spectrum sunscreen containing pigments, such as iron oxide, may be required for melasma prevention. There is no conclusive clinical evidence that daily sunscreen use is unsafe or that it compromises vitamin D synthesis.

CONCLUSION

Daily use of broad-spectrum sunscreen containing antioxidant and anti-aging active ingredients can effectively reduce extrinsic aging.

Melasma treatment: a systematic review

Melasma is a common chronic refractory disorder of pigmentation affecting people with darker skin types. Overall prevalence varies between 8.8% and 40%, depending on the ethnicity of the population and the geographical area. Therapeutic management of melasma is challenging, with high recurrence rates which significant impacts on the quality of life. No single treatment is universally efficacious. Systemic treatments with tranexamic acid and polypodium leucotmatous had promising results, although the former was related to systemic side effects. Microneedling and peeling were also efficacious, although their superiority to topical hydroquinone, the gold standard in melasma treatment, remains to be established. Similarly, laser and light devices have been beneficial. However, recurrence rates remain high in all treatment groups. Combination therapies, either in double or triple combinations yielded the best results when compared to single terapies. Treatment choice should be made after Wood's lamp examination, as well as dermatoscopic evaluation, in order to select the best treatment option, targeted at each melasma subtype.

Visible light. Part II: Photoprotection against visible and ultraviolet light

Cutaneous photobiology studies have focused primarily on the ultraviolet portion of the solar spectrum. Visible light (VL), which comprises 50% of the electromagnetic radiation that reaches the Earth's surface and, as discussed in Part I of this CME, has cutaneous biologic effects, such as pigment darkening and erythema. Photoprotection against VL includes avoiding the sun, seeking shade, and using photoprotective clothing. The organic and inorganic ultraviolet filters used in sunscreens do not protect against VL, only tinted sunscreens do. In the United States, these filters are regulated by the Food and Drug Administration as an over-the-counter drug and are subject to more stringent regulations than in Europe, Asia, and Australia. There are no established guidelines regarding VL photoprotection. Alternative measures to confer VL photoprotection are being explored. These novel methods include topical, oral, and subcutaneous agents. Further development should focus on better protection in the ultraviolet A1 (340-400 nm) and VL ranges while enhancing the cosmesis of the final products.

History of sunscreen: An updated view

BACKGROUND

With the global sunscreen market expected to reach $24.4 billion worldwide by 2029, this demonstrates the increasing awareness of the damaging effects of sunlight. Sunscreen has been gradually evolving, and new photoprotective ingredients are continuing to be produced in response to growing scientific evidence on the effect of solar radiation on the skin.

AIMS

This literature review aims to provide an updated view of the history of sunscreens.

METHODS

A literature search was conducted with the keywords "Sunscreen, history, regulation, ultraviolet A, ultraviolet B, visible light" from PubMed, Medline, and online search engines.

RESULTS

Humankind has always found ways to provide photoprotection since 4000BC. Only in the last century, evidence-based sunscreens have existed. The first ultraviolet B filters were produced in 1928, its evidence of efficacy and safety discovered in 1956 and development of sun protection factor in 1974. Similarly, sunscreen containing ultraviolet A filters was released in 1980 and the ultraviolet A star rating system developed in 1992. Regulatory bodies for sunscreen were introduced in the 1970s and have sought to review the safety and efficacy of ingredients. With the rising number of researches on the effects of visible light on hyperpigmentation over the past decade, the need for photoprotection beyond ultraviolet has been increasing.

CONCLUSION

To provide consumers with evidence-based sunscreen, challenges remain in acquiring further evidence, regulation, and rating systems.