A method to assess the protective efficacy of sunscreens against visible light-induced pigmentation

Blue light protection factor: a method to assess the protective efficacy of cosmetics against blue light-induced skin damage in the Chinese population

BACKGROUND

Previous studies have shown that visible light (VL), especially blue light (BL), could cause significant skin damage. With the emergence of VL protection products, a harmonization of light protection methods has been proposed, but it has not been widely applied in the Chinese population.

OBJECTIVE

Based on this framework, we propose an accurate and simplified method to evaluate the efficacy of BL photoprotection for the Chinese population.

METHODS

All subjects (n = 30) were irradiated daily using a blue LED light for four consecutive days. Each irradiation dose was 3/4 MPPD (minimum persistent pigmentation darkening). The skin pigmentation parameters, including L*, M, and ITA°, were recorded. We proposed the blue light protection factor (BPF) metric based on the skin pigmentation parameters to evaluate the anti-blue light efficacies of different products.

RESULTS

We found that the level of pigmentation rose progressively and linearly as blue light exposure increased. We proposed a metric, BPF, to reflect the anti-blue light efficacy of products based on the linear changes in skin pigment characteristics following daily BL exposure. Moreover, we discovered that the BPF metric could clearly distinguish the anti-blue light efficacies between two products and the control group, suggesting that BPF is an efficient and simple-to-use metric for anti-blue light evaluation.

CONCLUSION

Our study proposed an accurate and simplified method with an easy-to-use metric, BPF, to accurately characterize the anti-blue light efficacies of cosmetic products, providing support for further development of anti-blue light cosmetics.

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.

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.

Commercial visible-light protecting sunscreens for photosensitive individuals

Visible light sensitivity can have a severe adverse impact on quality of life leading to withdrawal from social activity during daylight hours. Treatment options are limited and expensive. Commercially available sunscreens that provide visible light protection is of immediate practical importance, particularly for patients with Erythropoietic Protoporphyria (EPP) and Solar Urticaria as they experience intense symptoms of pain, burning, itch and urticarial rash or phototoxic erythema within seconds to minutes of even minor VL exposure.

Review on photoprotection: a clinician’s guide to the ingredients, characteristics, adverse effects, and disease-specific benefits of chemical and physical sunscreen compounds

Photoprotection is a critical health prevention strategy to reduce the deleterious effects of ultraviolet radiation (UVR) and visible light (VL). Methods of photoprotection are reviewed in this paper, with an emphasis on sunscreen. The most appropriate sunscreen formulation for personal use depends on several factors. Active sunscreen ingredients vary in their protective effect over the UVR and VL spectrum. There are dermatologic diseases that cause photosensitivity or that are aggravated by a particular action spectrum. In these situations, sunscreen suggestions can address the specific concern. Sunscreen does not represent a single entity. Appropriate personalized sunscreen selection is critical to improve compliance and clinical outcomes. Health care providers can facilitate informed product selection with awareness of evolving sunscreen formulations and counseling patients on appropriate use. This review aims to summarize different forms of photoprotection, discuss absorption of sunscreen ingredients, possible adverse effects, and disease-specific preferences for chemical, physical or oral agents that may decrease UVR and VL harmful effects.

Assessment of sun-safety education behavior via spectrophotometric evaluation: A preliminary study

BACKGROUND

Biases inherent in self-assessment of sun exposure and sun-safe behavior may lead to inaccurate conclusions about the effectiveness of sun-safety educational programs.

OBJECTIVES

We aimed to compare self-reports to objective measures of sun exposure, when examining the effectiveness of passive versus active educational interventions.

METHODS

From May to June 2018, 73 participants recruited at a dermatology clinic were sequentially assigned to receive sun-safety education through one of 3 modes: interactive online module, video, or no education. A baseline Sun Exposure and Behavior Inventory (SEBI) questionnaire was administered, and spectrophotometric measurements of sun-exposed and sun-protected areas were taken and reported in the CIE L*a*b* color space. Participants were followed 4-8 and 16 weeks after the initial visit where the SEBI was re-administered, and serial measurements of skin color were taken. The change in SEBI scores and L*a*b values, as calculated by the individual typology angle (ITA°), was analyzed.

RESULTS

There was a significant increase in skin darkening in all the groups at 4-8 and 16 weeks follow-up. There was no statistically significant difference between the groups in the magnitude of color change. However, subjectively at 4-8 weeks post-intervention, participants in the interactive module and video groups had significantly improved self-reported SEBI scores compared to control (p < .05, Kruskal-Wallis). By 16 weeks, only the interactive module group showed significant improvement in SEBI scores compared to control (p < .05, ANOVA).

CONCLUSION

In determining the effectiveness of sun-safety programs, spectrophotometric evaluation of sun-induced skin pigmentation can allow for a more complete evaluation of self-reported sun exposure and sun-protective behavior.

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.

Prevention of Polymorphic Light Eruption Afforded by a Very High Broad-Spectrum Protection Sunscreen Containing Ectoin

Introduction

Polymorphic light eruption (PLE) is the most common idiopathic, acquired photodermatosis. The pathophysiology of PLE is not yet fully understood but seems to involve immunological mechanisms, UVA-induced oxidative stress, and the subsequent elicitation of a cellular stress response affecting keratinocyte gene expression and skin immune function. In the present study, a high broad-spectrum sunscreen medical device (MD), containing a very high protection complex of UVB and UVA filters and ectoin, was investigated for its ability to protect against UVA-induced PLE.

Methods

The study was carried out as a monocentric, double-blinded, randomized, untreated controlled design. The test MD was applied (2 mg/cm²) on one side of the chest according to a randomization list of 15 patients with a typical history of PLE, and the contralateral area remained untreated. After product application, the test areas were exposed daily to increasing doses of UVA radiation (from 40 to 60 J/cm²) until a PLE reaction was detected or for a maximum of five consecutive days. Evaluations of induced PLE included clinical scoring and chromametry for erythema and pigmentation.

Results

Overall, no positive PLE reaction was observed on the side of the chest treated by the test MD, whereas positive PLE reactions were triggered on the untreated side of 13 subjects. Subjective sensations were very rare on the MD-treated side but were numerous and more severe on the untreated side. Chromametry and clinical visual inspection indicated that the skin color was unchanged on the MD-protected side, whereas high increased values of erythema and pigmentation were observed on the untreated chest side.

Conclusion

This MD sunscreen based on a complex of UVA–UVB filters and 1% of ectoin may be effective in preventing UVA-induced PLE. New studies comparing this MD sunscreen versus the same product without ectoin should be conducted.

ClinicalTrials.gov identifier: NCT05320315 (retrospectively registered 09/17/2021).

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00755-5.

[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.

A new visible light absorbing organic filter offers superior protection against pigmentation by wavelengths at the UVR-visible boundary region

Skin pigmentation by solar ultraviolet radiation (UVR; ~295-400 nm) is well established. More recently, visible light (VL; 400-740 nm) has been shown to induce rapid pigmentation. Such pigmentation is thought to be caused by oxidative stress, which has associations with skin cancer and photoageing. However, the UVR-VL boundary region has been less well studied. The lower back of healthy Fitzpatrick skin type II-IV individuals was irradiated with increasing doses of narrow-band 385 nm and 405 nm radiation. Pigmentation change was measured immediately, 6 h and 24 h post-irradiation using two reflectance spectroscopy devices and visual grading. Pigmentation was dose-dependently increased in all skin types and time points for both spectra. Two sunscreens, both labelled SPF 15 and UVA protective in the EU and USA (but with different Boots star rating in the UK, 2* vs 5*) were compared. Their formulations were the same apart from the addition of a new organic filter bis-(diethylaminohydroxybenzoyl benzoyl) piperazine (BDBP) that absorbs between 350 and 425 nm. The product that lacked BDBP provided minimal protection against pigmentation, but its addition provided almost complete protection. This demonstrates the needs to improve photoprotection at the UVR-visible border and for sunscreens to act as neutral density filters.

Sunscreen lotions in the dermatological prescription: review of concepts and controversies

The skin is regularly exposed to several environmental aggressions, including solar radiation, whose biological effects can induce sunburn, dyschromia, skin aging and cancer. Among the photoprotection measures, sunscreens comprise a relevant part of the strategy aimed to prevent solar radiation damage and, for effective action, the patient must adhere to the product use and the latter, in turn, must follow technical parameters to promote adequate protection. This review article brings together the most current and relevant concepts about photoprotection for dermatological use, including the challenges for their formulation, the risks of certain photoprotective active substances for individual and environmental safety and the importance of stringency in determining the product efficacy, considering the regulatory aspects, highlighting relevant differences between Brazil and other countries. Thus, when assessing a sunscreen, not only the visual aspects and sensory perception will be immediately evaluated, but also the quality and suitability of the vehicle, the chemical composition of the formulation, the environmental risks, the photostability of the screening system, and the measurement of its protection spectrum. Technical knowledge of sunscreens can help dermatologists in this important role of educating patients about the best photoprotective strategies in each situation.

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.

Snail slime-based gold nanoparticles: An interesting potential ingredient in cosmetics as an antioxidant, sunscreen, and tyrosinase inhibitor

Due to their properties, snail slime-based products have been appreciated and used worldwide. So, as an alternative and innovative use of snail slime, it was adopted to induce gold nanoparticles' formation, conferring them interesting properties. By a simple, one-pot, and eco-friendly approach, 14 ± 6 nm wide hybrid gold nanoparticles, having an inorganic metallic core decorated by the slime's main components, were obtained. Among their several properties, their antioxidant and tyrosinase inhibition activity were investigated through the DPPH and ABTS and the tyrosinase assays, respectively. After assessing their non-cytotoxicity in our previous work, the results revealed positive responses, enabling their use as a potential novel multifunctional ingredient in cosmetics. Interestingly, the gold nanoparticle photostability, investigated by means of a solar simulator lamp, suggests using them in commercial cosmetic sunscreen products as a potential alternative to the commonly used inorganic sunscreen ingredients. The theoretical Sun Protection Factor was evaluated, obtaining values in the range 0-12. The proposed environmentally friendly and cost-effective protocol for nanoparticle synthesis, following the principles of Green Chemistry, opens a hugely attractive space toward the study of snail slime-based gold nanoparticles as a potential multipurpose platform in cosmetics.

Pigmentation effects of blue light irradiation on skin and how to protect against them

Background

Visible light, in particular blue light, has been identified as an additional contributor to cutaneous photoageing. However, clinical studies demonstrating the clear effect of blue light on photoageing are still scarce, and so far, most studies have focused on broad‐spectrum visible light. Although there is evidence for increased skin pigmentation, the underlying mechanisms of photoageing in vivo are still unclear. Furthermore, there is still a need for active ingredients to significantly protect against blue light‐induced hyperpigmentation in vivo.

Our study had two aims: to detect visible changes in skin pigmentation following repeated irradiation of the skin with LED‐based blue light and to reduce pigmentation using suitable active ingredients.

Method

We conducted a randomized, double‐blind and placebo‐controlled clinical study on 33 female volunteers with skin phototypes III and IV. We used a repetitive blue light (4 × 60 J cm⁻², 450 nm) irradiation protocol on the volunteers’ inner forearms. Using hyperspectral imaging, we assessed chromophore status. In addition, we took chromameter measurements and photographs to assess visible hyperpigmentation.

Results

We measured significant changes in chromophore status (P < 0.001 vs baseline), that is of melanin, haemoglobin and oxygen saturation, immediately after blue light irradiation. In addition, we found visible skin colour changes which were expressed by a significant decrease in ITA° values (delta ITA° = −16.89, P < 0.001 vs baseline for the placebo group) and an increase in a* (delta a* = +3.37, P < 0.001 vs baseline for the placebo group) 24 h post‐irradiation. Hyperpigmentation and skin reddening were mitigated by both a formulation containing 3% of a microalgal product and a formulation containing 3% niacinamide.

Conclusion

Our study sets out an efficient and robust protocol for investigating both blue light‐induced cutaneous alterations, such as changes in skin chromophores, and signs of photoageing, such as hyperpigmentation. Moreover, we have shown evidence that both an extract of the microalga Scenedesmus rubescens and niacinamide (vitamin B3) have the potential to protect against blue light‐induced hyperpigmentation.

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.

Recommendations for the use of corrective makeup after dermatological procedures

Introduction

The number of dermatological or cosmetic procedures carried out has continuously increased over the last decades. Almost all may cause transient local skin reactions such as erythema, blistering, crusts, scaling, hypo‐ or hyperpigmentation, or hemorrhagic lesions. One issue of dermatological procedures is the downtime, during which patients need to hide their skin, due to these local reactions.

Aim

To provide dermatologists with easy‐to‐follow recommendations for the right timing of use of corrective makeup for patients who have undergone or who plan to undergo dermatological procedures, according to the invasiveness of the dermatological procedure chosen.

Methodology

A group of experts in dermatological procedures met in 2019 and at the beginning of 2020 to discuss the different procedures, their local reactions and downtime, and the opportunities to use specific corrective makeup in order to hide these transient reactions.

Results

As a result of the discussions, the experts proposed a tabulated algorithm of use based on a classification of the different dermatological procedures according to their invasiveness and recommended timing of the first post‐procedure corrective makeup application.

Conclusion

Corrective makeup may be considered as a complement to certain dermatological procedures in order to minimize downtime. However, its use is conditioned by the correct understanding of skin barrier alteration and recovery time. The proposed algorithm of use of corrective makeup after procedures may help the practitioner to indicate his patient the right moment for applying corrective makeup in order to avoid local tolerance issues and post‐procedure complications.

Efficacy of ethyl ascorbyl ether-containing cosmetic cream on blue light-induced skin changes

BACKGROUND

Office workers are consistently exposed to blue light, mainly from sunlight and digital device. Recent studies report that blue light has various harmful effects, including cellular changes via reactive oxygen species. Studies on blue light-induced skin changes have only been conducted in vitro and have not been clinically confirmed.

OBJECTIVE

We provide novel methods to evaluate the effect of the product on the recovery of skin changed by blue light.

METHODS

Internet surveys were conducted for workers in their 20s and 40s regarding exposure time to blue light in various environments. To study the effects of long-term exposure to blue light (456 nm) on the skin, we designed three light intensity conditions, and various skin characteristics were observed. After blue light irradiation, various skin characteristics were analyzed before and after applying ethyl ascorbyl ether (EAE)-containing cosmetic cream for 2 weeks.

RESULTS

When exposed to strong blue light for approximately 16 days, the L^* value, skin hydration, transparency, and elasticity decreased, and the melanin index, erythema index, a^* value, and b^* value increased. Furthermore, after short-term blue light irradiation (dose, 269 J/cm² , the equivalent of blue light exposure for approximately 38 days in daily life), the L^* value and elasticity decreased, and the melanin index and erythema index increased. However, when EAE cream was applied on skin for 1-2 weeks, the skin recovered.

CONCLUSION

This study clinically confirms the skin changes caused by blue light and the effect of EAE in relieving such changes.

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.

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.

[Sun-damaged skin (photoaging): what is new?]

Skin aging results from the interaction of genetic and nongenetic so-called exposomal, factors. Among the exposomal factors, chronic, life-long exposure to sunlight is of eminent importance for the development of skin aging characteristics. Importantly, photoaging of human skin is not only caused by ultraviolet (UV) B and A radiation, but is also the consequence of exposure to wavelengths beyond the UV spectrum. These include visible, i.e. blue light (400-440 nm) as well as the short part of infrared radiation, i.e. IRA (760-1200 nm). Here we summarize the scientific evidence supporting these conclusions and emphasize the resulting consequences for daily photoprotection of human skin. We also explain the clinical significance of the concept that is offered by the skin aging exposome, which e.g. takes into account the fact that sunlight interacts with other exposomal factors and that this interaction is important for photoaging of the skin.

A Corrective Cosmetic Improves the Quality of Life and Skin Quality of Subjects with Facial Blemishes Caused by Skin Disorders

Background

Facial blemishes resulting from skin disorders have a significant effect on the patient’s self-esteem and impact quality of life (QOL).

Aim

To assess the impact of a corrective cosmetic (CC) on QOL on top of skin quality parameters.

Methods

An international observational study was conducted on subjects with visible facial flaws that would benefit from a corrective cosmetic. Investigators collected data regarding demographics, QOL using the Skindex-16 scale, skin dryness and tautness, subject and investigator satisfaction, cosmetic acceptability and tolerance at baseline and after 4 to 6 weeks of daily use.

Results

A total of 1840 subjects participated; the mean age was 31.5±11.1 and 95% were women. Acne accounted for 48.9% of skin conditions, followed by melasma (16.7%) and rosacea (15.3%). Of the subjects 81.2% had at least 10% of the face affected and the condition was rated as disfiguring by 45.3% of the subjects; 45.0% and 44.4%, respectively, had neither taut nor dry skin at baseline. Baseline Skindex-16 scores for symptoms, emotions, functioning and overall were 1.4±1.3, 3.5±1.6, 2.4±1.8 and 2.4±1.3, respectively, on a scale from 0 to 6. Compliance was 96.0±10.6%. At the end of the study, Skindex-16 scores had significantly (p<0.0001) improved for all parameters, as did skin dryness and tautness. Subject and investigator satisfaction were high or very high; cosmetic acceptability was high or very high and local tolerance good or very good.

Conclusion

The tested corrective cosmetic significantly improved the QOL of subjects with significant facial flaws, skin tautness and dryness, and was well tolerated.

Photoprotection of the future: challenges and opportunities

The use of sunscreens is an important and essential component of photoprotection. Since their introduction during the first half of the last century, sunscreens have benefited enormously from major technological advances such as the development of novel UV filters; as a result, their efficacy in preventing UV-induced erythema is unequivocal. More recently, however, new challenges have appeared, which have prompted a robust discussion about the safety of sunscreens. These include topics directly related to photoprotection of human skin such as improved/alternative methods for standardization of assessment of the efficacy of sunscreens, but also many others such as photoprotection beyond UV, concerns about human toxicity and ecological safety, the potential of oral photoprotective measures, consequences of innovative galenic formulations. On a first glance, some of these might raise questions and doubts among dermatologists, physicians and the general public about the use sunscreens as a means of photoprotection. This situation has prompted us to critically review such challenges, but also opportunities, based on existing scientific evidence. We conclude by providing our vision about how such challenges can be met best in the future in an attempt to create the ideal sunscreen, which should provide adequate and balanced protection and be easy and safe to use.

High-energy visible light at ambient doses and intensities induces oxidative stress of skin-Protective effects of the antioxidant and Nrf2 inducer Licochalcone A in vitro and in vivo

BACKGROUND

Solar radiation causes skin damage through the generation of reactive oxygen species (ROS). While UV filters effectively reduce UV-induced ROS, they cannot prevent VIS-induced (400-760 nm) oxidative stress. Therefore, potent antioxidants are needed as additives to sunscreen products.

METHODS

We investigated VIS-induced ROS formation and the photoprotective effects of the Nrf2 inducer Licochalcone A (LicA).

RESULTS

Visible spectrum of 400-500 nm dose-dependently induced ROS in cultured human fibroblasts at doses equivalent to 1 hour of sunshine on a sunny summer day (150 J/cm² ). A pretreatment for 24 hours with 1 µmol/L LicA reduced ROS formation to the level of unirradiated cells while UV filters alone were ineffective, even at SPF50+. In vivo, topical treatment with a LicA-containing SPF50 + formulation significantly prevented the depletion of intradermal carotenoids by VIS irradiation while SPF50 + control did not protect.

CONCLUSION

LicA may be a useful additive antioxidant for sunscreens.

Sunscreen photoprotection and vitamin D status

Background

Global concern about vitamin D deficiency has fuelled debates on photoprotection and the importance of solar exposure to meet vitamin D requirements.

Objectives

To review the published evidence to reach a consensus on the influence of photoprotection by sunscreens on vitamin D status, considering other relevant factors.

Methods

An international panel of 13 experts in endocrinology, dermatology, photobiology, epidemiology and biological anthropology reviewed the literature prior to a 1‐day meeting in June 2017, during which the evidence was discussed. Methods of assessment and determining factors of vitamin D status, and public health perspectives were examined and consequences of sun exposure and the effects of photoprotection were assessed.

Results

A serum level of ≥ 50 nmol L⁻¹ 25(OH)D is a target for all individuals. Broad‐spectrum sunscreens that prevent erythema are unlikely to compromise vitamin D status in healthy populations. Vitamin D screening should be restricted to those at risk of hypovitaminosis, such as patients with photosensitivity disorders, who require rigorous photoprotection. Screening and supplementation are advised for this group.

Conclusions

Sunscreen use for daily and recreational photoprotection does not compromise vitamin D synthesis, even when applied under optimal conditions.

What's already known about this topic?

Knowledge of the relationship between solar exposure behaviour, sunscreen use and vitamin D is important for public health but there is confusion about optimal vitamin D status and the safest way to achieve this.

Practical recommendations on the potential impact of daily and/or recreational sunscreens on vitamin D status are lacking for healthy people.

What does this study add?

Judicious use of daily broad‐spectrum sunscreens with high ultraviolet (UV) A protection will not compromise vitamin D status in healthy people.

However, photoprotection strategies for patients with photosensitivity disorders that include high sun‐protection factor sunscreens with high UVA protection, along with protective clothing and shade‐seeking behaviour are likely to compromise vitamin D status.

Screening for vitamin D status and supplementation are recommended in patients with photosensitivity disorders.

Linked Comment: https://doi.org/10.1111/bjd.18126.

https://doi.org/10.1111/bjd.18494 available online

New oral and topical approaches for the treatment of melasma

Melasma is a common, therapeutically challenging, and universally relapsing disorder of hyperpigmentation that is most often observed in women and individuals with Fitzpatrick Skin Types III through VI. The pathogenesis of melasma is complex and protean. Contributing factors that are often implicated in the etiopathogenesis of this condition include a genetic predisposition, intense ultraviolet radiation exposure, and hormonal influences. Therapeutic interventions for melasma include a multimodality approach incorporating photoprotection agents, topical and oral skin lighteners, and resurfacing procedures. Given our expanding knowledge of the pathogenesis of melasma, new and effective treatments are expanding our therapeutic armamentarium. This article reviews new and emerging oral and topical treatments for melasma.

Clinical and Biological Characterization of Skin Pigmentation Diversity and Its Consequences on UV Impact

Skin color diversity is the most variable and noticeable phenotypic trait in humans resulting from constitutive pigmentation variability. This paper will review the characterization of skin pigmentation diversity with a focus on the most recent data on the genetic basis of skin pigmentation, and the various methodologies for skin color assessment. Then, melanocyte activity and amount, type and distribution of melanins, which are the main drivers for skin pigmentation, are described. Paracrine regulators of melanocyte microenvironment are also discussed. Skin response to sun exposure is also highly dependent on color diversity. Thus, sensitivity to solar wavelengths is examined in terms of acute effects such as sunburn/erythema or induced-pigmentation but also long-term consequences such as skin cancers, photoageing and pigmentary disorders. More pronounced sun-sensitivity in lighter or darker skin types depending on the detrimental effects and involved wavelengths is reviewed.

Novel Means for Photoprotection

Due to changes in human lifestyle (expanded sunbathing, the use of solaria, etc.) and, most importantly, increasing lifetime and thus higher cumulative exposure to solar radiation, skin aging and skin cancer have become major health issues. As a consequence effective photoprotection is of outmost importance to humans. In this regard a lot has been learned in the past about the cellular and molecular basis underlying ultraviolet (UV) radiation-induced skin damage and, based on this knowledge, numerous skin protective approaches including organic and inorganic UV-filters, but also topically applicable antioxidants, DNA repair enzymes and compatible solutes as well as oral photoprotective strategies based on nutritional supplements have been developed. A new aspect is here that sun protection of human skin might even be possible after solar radiation-induced skin damage has occurred. A second, very important development was prompted by the discovery that also wavelengths beyond the UV spectrum can damage human skin. These include the blue light region of visible light (VIS) as well as the near infrared range (IRA) and corresponding sunprotection strategies have thus recently been or are still being developed. In this article we will provide a state of the art summary of these two novel developments and, at the end, we will also critically discuss strengths and weaknesses of the current attempts, which mainly focus on the prevention of skin damage by selected wavelengths but greatly ignore the possibility that wavelengths might interfere with each other. Such combined effects, however, need to be taken into account if photoprotection of human skin is intended to be global in nature.

Mitochondrial damage and cytoskeleton reorganization in human dermal fibroblasts exposed to artificial visible light similar to screen-emitted light

BACKGROUND

Artificial visible light is everywhere in modern life. Social communication confronts us with screens of all kinds, and their use is on the rise. We are therefore increasingly exposed to artificial visible light, the effects of which on skin are poorly known.

OBJECTIVE

The purpose of this study was to model the artificial visible light emitted by electronic devices and assess its effect on normal human fibroblasts.

METHODS

The spectral irradiance emitted by electronic devices was optically measured and equipment was developed to accurately reproduce such artificial visible light. Effects on normal human fibroblasts were analyzed on human genome microarray-based gene expression analysis. At cellular level, visualization and image analysis were performed on the mitochondrial network and F-actin cytoskeleton. Cell proliferation, ATP release and type I procollagen secretion were also measured.

RESULTS

We developed a device consisting of 36 LEDs simultaneously emitting blue, green and red light at distinct wavelengths (450 nm, 525 nm and 625 nm) with narrow spectra and equivalent radiant power for the three colors. A dose of 99 J/cm2 artificial visible light was selected so as not to induce cell mortality following exposure. Microarray analysis revealed 2984 light-modulated transcripts. Functional annotation of light-responsive genes revealed several enriched functions including, amongst others, the "mitochondria" and "integrin signaling" categories. Selected results were confirmed by real-time quantitative PCR, analyzing 24 genes representing these two categories. Analysis of micro-patterned culture plates showed marked fragmentation of the mitochondrial network and disorganization of the F-actin cytoskeleton following exposure. Functionally, there was considerable impairment of cell growth and spread, ATP release and type I procollagen secretion in exposed fibroblasts.

CONCLUSION

Artificial visible light induces drastic molecular and cellular changes in normal human fibroblasts. This may impede normal cellular functions and contribute to premature skin aging. The present results extend our knowledge of the effects of the low-energy wavelengths that are increasingly used to treat skin disorders.