Photobiomodulation CME part II: Clinical applications in dermatology.

Photobiomodulation (PBM) is an emerging treatment modality in dermatology with increasing office and home-based use. PBM is the use of various light sources in the red light (620-700 nm) and near-infrared (700-1440 nm) spectrum as a form of light therapy. PBM is often administered through low-level lasers or light-emitting diodes. Studies show that PBM can be used effectively to treat conditions secondary to cancer therapies, alopecia, ulcers, herpes simplex virus, acne, skin rejuvenation, wounds, and scars. PBM offers patients many benefits compared to other treatments. It is noninvasive, cost-effective, convenient for patients, and offers a favorable safety profile. PBM can be used as an alternative or adjuvant to other treatment modalities including pharmacotherapy. It is important for dermatologists to gain a better clinical understanding of PBM for in-office administration and to counsel patients on proper application for home-use devices to best manage safety and expectations as this technology develops. PBM wavelengths can induce varied biological effects in diverse skin types, races, and ethnicities; therefore, it is also important for dermatologists to properly counsel their skin of color patients who undergo PBM treatments. Future clinical trials are necessary to produce standardized recommendations across conditions and skin types.

Integrating skin color assessments into clinical practice and research: A review of current approaches.

Skin color classification can have importance in skin health, pigmentary disorders, and oncologic condition assessments. It is also critical for evaluating disease course and response to a variety of therapeutic interventions and aids in accurate classification of participants in clinical research studies. A panel of dermatologists conducted a literature review to assess the strengths and limitations of existing classification scales, as well as to compare their preferences and utilities. We identified 17 skin classification systems utilized in dermatologic settings. These systems include a range of parameters such as UV light reactivity, race, ethnicity, and degree of pigmentation. The Fitzpatrick skin type classification is most widely used and validated. However it has numerous limitations including its conflation with race, ethnicity, and skin color. There is a lack of validation data available for the remaining scales. There are significant deficiencies in current skin classification instruments. Consensus-based initiatives to drive the development of validated and reliable tools are critically needed.

Photobiomodulation CME Part I: Overview and Mechanism of Action.

Photobiomodulation (PBM), previously known as low-level laser light therapy, represents a non-invasive form of phototherapy that utilizes wavelengths in the red light (RL, 620-700 nm) portion of the visible light (VL, 400-700 nm) spectrum and the near-infrared (NIR, 700-1440 nm) spectrum. PBM is a promising and increasingly used therapy for the treatment of various dermatologic and non-dermatologic conditions. Photons from RL and NIR are absorbed by endogenous photoreceptors including mitochondrial cytochrome C oxidase (COX). Activation of COX leads to the following changes: modulation of mitochondrial adenosine triphosphate (ATP), generation of reactive oxygen species (ROS), and alterations in intracellular calcium levels. The associated modulation of ATP, ROS and calcium levels promotes the activation of various signaling pathways (e.g., insulin-like growth factors, phosphoinositide 3-kinase pathways), which contribute to downstream effects on cellular proliferation, migration and differentiation. Effective PBM therapy is dependent on treatment parameters (e.g., fluence, treatment duration and output power). PBM is generally well-tolerated and safe with erythema being the most common and self-limiting adverse cutaneous effect.

A narrative review of the impact of ultraviolet radiation and sunscreen on the skin microbiome.

BACKGROUND: The human skin microbiome is a dynamic ecosystem that plays an important role in skin health. The skin microbiome has been implicated in numerous diseases, and our knowledge surrounding it continues to evolve. A better understanding of the interactions between the environment and the skin microbiome will lead to improvements in skin health. METHODS: This article reviews the published literature surrounding the impact of ultraviolet radiation (UVR) and sunscreen on the skin microbiome. RESULTS: Skin microbes are differentially impacted by UVR, and alterations in the microbiome can be detected following UVR exposure. These changes are related to direct bactericidal effects, alterations in the cutaneous metabolome, and changes in the cutaneous immune system. UV filters used in sunscreen have been shown to have bactericidal effects, and many compounds used in sunscreen emulsions can also negatively impact cutaneous microbes. CONCLUSION: A healthy microbiome has been shown to produce compounds that help protect the skin from UVR, and sunscreen has the potential to reduce the diversity of the skin microbiome. This indicates that designing sunscreen products that both provide protection against UVR and preserve the skin microbiome may offer additional benefits to skin health when compared with traditional sunscreen products.

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.

Optimisation of skin phototype classification.

Understanding individuals' skin pigmentation and photosensitivity is important in judging risk of skin cancer and response to certain treatment modalities. However, individuals with darkly pigmented skin are poorly represented in the widely used Fitzpatrick skin phototype (FST) system. Moreover, the FST system is prone to misuse, as it relies on subjective patient and clinician assessment of skin type, and does not clearly differentiate pigmentation from photosensitivity. By evaluating the key literature surrounding the FST system, its criticisms and proposed alternatives, this review serves to understand how skin phototype classification can be optimised.

Imaging technologies for presurgical margin assessment of basal cell carcinoma.

Basal cell carcinoma is the most common cancer worldwide, necessitating the development of techniques to decrease treatment costs through efficiency and efficacy. Mohs micrographic surgery, a specialized surgical technique involving staged resection of the tumor with complete histologic evaluation of the peripheral margins, is highly utilized. Reducing stages by even 5% to 10% would result in significant improvement in care and economic benefits. Noninvasive imaging could aid in both establishing the diagnosis of suspicious skin lesions and streamlining the surgical management of skin cancers by improving presurgical estimates of tumor sizes. Herein, we review the current state of imaging techniques in dermatology and their applications for diagnosis and tumor margin assessment of basal cell carcinoma prior to Mohs micrographic surgery.

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.

The cutaneous effects of blue light from electronic devices: a systematic review with health hazard identification.

The biologic effects of visible light, particularly blue light, on the skin at doses and irradiances representative of sunlight have been established. Recent research studies investigated the effects of blue light (BL) from electronic screen devices; however, it is unclear if the evidence can be generalized to real life. The aim of this systematic review was to evaluate available evidence regarding clinical effects of BL emitted from electronic devices on human skin using the framework established by the Office of Health Assessment and Translation (OHAT). A systematic literature search was conducted by two librarians in Ovid MEDLINE, Embase.com, and Web of Science for relevant articles published from 1946 to March 2022. In vitro and in vivo studies that investigated the effects of BL from electronic devices on skin were included. From the 87 articles gathered from database searches and 1 article identified from citation search, only 9 met the inclusion criteria (6 in vitro and 3 in vivo studies). Human and animal literature with the highest level of evidence ratings were considered with mechanistic data to form one of five human hazard identifications for each outcome category using the OHAT protocol: (1) known, (2) presumed, (3) suspected, (4) not classifiable, or (5) not identified to be a hazard to humans. Literature-based evidence integration did not identify exposure to BL from electronic devices as a hazard to skin pigmentation, redness, yellowness, or melasma exacerbation. Exposure to BL from electronic devices was not classified as a skin photoaging hazard. Low confidence in representative exposure characterization drove high OHAT risk-of-bias ratings for the majority of included studies. While these conclusions hold true for the limited existing data, a larger number of future studies with high-confidence evidence are needed to verify and strengthen hazard identification conclusions.

Evaluation of efficacy of antioxidant-enriched sunscreen prodcuts against long wavelength ultraviolet A1 and visible light.

OBJECTIVE: The synergistic effects of VL and long wavelength UVA1 (VL + UVA1, 370-700 nm) on inducing pigmentation and erythema in skin have been demonstrated and linked to exacerbation of dermatologic conditions including melasma and post-inflammatory hyperpigmentation. This study aimed to compare the photoprotection of organic sunscreens enriched with antioxidant (AO) combinations against VL + UVA1 induced biologic effects. The efficacy was compared with that offered by a commercially available tinted sunscreen. METHODS: Ten healthy adult subjects with Fitzpatrick skin phototypes IV-VI were enrolled (nine completed). VL + UVA1 dose of 380 J/cm2 was utilized. Assessment methods were polarized photography, investigator global scoring and diffuse reflectance spectroscopy (DRS). Measurements were obtained at baseline and immediately, 24 h and 7 days after irradiation. RESULTS: Sites treated with tinted sunscreen product had significantly less pigmentation compared with untreated but irradiated skin at all time points. However, DRS results demonstrated that the 5-AO sunscreen performed comparably or better than all sunscreens tested with relatively lower dyschromia, delayed erythema and pigmentation. CONCLUSION: These results highlight the potential of AO-enriched sunscreens to be photoprotective against VL + UVA1. The combination of efficacy and the cosmetic appearance of this product may provide wider acceptability which is crucial considering the limited available means of protection against this waveband.

OBJECTIF: les effets synergiques de la lumière visible (LV) et des rayons ultraviolets long (UVA1) (LV + UVA1, 370 à 700 nm) sur l'induction de la pigmentation et de l'érythème cutané ont été démontrés et liés à l'exacerbation des affections dermatologiques, notamment le mélasma et l'hyperpigmentation post-inflammatoire. Cette étude visait à comparer la photoprotection des écrans solaires organiques enrichis en associations antioxydantes (AO) contre les effets biologiques induits par LV+UVA1. L'efficacité a été comparée à celle offerte par un écran solaire teinté disponible dans le commerce. MÉTHODES: dix sujets adultes en bonne santé présentant des phototypes cutanés de Fitzpatrick IV à VI ont été inclus (neuf ont terminé l'étude). On a utilisé une dose LV+UVA1 de 380 J/cm2. Les méthodes d'évaluation étaient la photographie polarisée, le score global de l'investigateur et la spectroscopie de réflectance diffuse (DRS). Les mesures ont été obtenues immédiatement à l'entrée dans l'étude et, 24 h et 7 jours après l'irradiation. RÉSULTATS: les sites traités avec un produit de protection solaire teinté présentaient une pigmentation significativement inférieure à celle de la peau non traitée mais irradiée, à toutes les heures de mesure. Cependant, les résultats de la DRS ont démontré que l'écran solaire 5-AO fonctionnait de manière comparable ou mieux que tous les écrans solaires testés avec une dyschromie, un érythème retardé et une pigmentation relativement plus faible. CONCLUSION: ces résultats mettent en évidence le potentiel des écrans solaires enrichis en AO comme facteur de photoprotection contre LV+UVA1. La combinaison de l'efficacité et de l'aspect esthétique de ce produit peut permettre une plus grande acceptabilité, ce qui est essentiel compte tenu de la disponibilité limitée des moyens de protection contre cette gamme d'ondes.

Visible Light and the Skin.

Visible light (VL, 400-700 nm) was previously regarded as nonsignificant with minimal to no photobiologic effects on the skin. Recent studies have demonstrated that in dark-skinned individuals (skin phototypes IV-VI), VL can induce more intense and longer lasting pigmentation compared to ultraviolet A1 (UVA1, 340-400 nm). Additionally, long wavelength UVA1 (370-400 nm) has been shown to potentiate these effects of VL. The combination of VL and UVA1 (VL + UVA1, 370-700 nm) was also able to induce erythema in light-skinned individuals (skin phototypes I-III), which is a novel finding since the erythemogenic spectrum of sunlight has primarily been attributed to ultraviolet B (UVB, 290-320 nm) and short wavelength UVA2 (320-340 nm) only. Although biologic effects of VL + UVA1 have been established, there are no guidelines in any country to test for photoprotection against this waveband. This invited perspective aims to present the evolution of knowledge of photobiologic effects of VL, associated phototesting methodologies, and current position on VL photoprotection.

Safety and Efficacy of Intense Pulsed Light With Radiofrequency in United States Hidradenitis Suppurativa Patients.

Copy: The combination of intense pulsed light and radiofrequency has been described in German populations to be a noninvasive therapy option for patients with hidradenitis suppurativa, demonstrating significant improvements in the quality of life and reduction in number of inflammatory lesions. OBJECTIVE: To evaluate the efficacy and safety of combination intense pulsed light and radiofrequency therapy in patients with hidradenitis suppurativa in the United States. METHODS: A prospective split body was conducted in the United States on patients with bilateral hidradenitis suppurativa. Subjects received 3 passes of intense pulsed light and radiofrequency per treatment session to a single involved body region on a randomized side of the body at least 2 weeks apart over 9 to 10 treatment sessions. RESULTS: When measured from baseline to final visit, the overall mean difference in Dermatology Life Quality Index was found to be statistically significant (-2.8, P=0.043, n = 9). Patients reported mild discomfort during therapy and no adverse events occurred during or after treatment sessions. CONCLUSIONS: Although statistically significant, the mean difference in Dermatology Life Quality Index in treated patients found in this study did not reach the minimal clinically important difference for inflammatory skin disease. J Drugs Dermatol. 2022;21(4):430-432. .doi:10.36849/JDD.6562.

Impact of visible light on skin health: The role of antioxidants and free radical quenchers in skin protection.

Until recently, the primary focus of photobiology has centered on the impact of UV radiation on skin health, including DNA damage and oncogenesis; however, the significant effects of visible light (VL) on skin remain grossly underreported. VL has been reported to cause erythema in individuals with light skin (Fitzpatrick skin types [FSTs] I-III) and pigmentary changes in individuals with dark skin types (FSTs IV-VI). These effects have importance in dermatologic diseases and potentially play a role in conditions aggravated by sun exposure, including phototoxicity in patients with FSTs I to III and post-inflammatory hyperpigmentation and melasma in patients with FSTs IV to VI. The induction of free radicals, leading to the generation of reactive species, is one driving mechanism of VL-induced skin pathologies, leading to the induction of melanogenesis and hyperpigmentation. Initial clinical studies have demonstrated the effectiveness of topical sunscreen with antioxidant combinations in inhibiting VL + UV-A1-induced erythema in FSTs I to III and reducing pigmentation in FSTs IV to VI. Antioxidants may help prevent the worsening of pigmentary disorders and can be incorporated into photoprotective strategies. It is essential that dermatologists and the public are aware of the impact of VL on skin, especially in patients with skin of color, and understand the available options for VL protection.

Individual Typology Angle and Fitzpatrick Skin Phototypes are Not Equivalent in Photodermatology.

Individual typology angle (ITA) measures constitutive pigmentation while skin phototypes (SPT) categories are based on sun reactiveness. However, the association between the two, ITA and SPT, is yet to be established. Since both systems provide six categories, recent studies have used ITA classifications as synonymous to SPT. The results of this study indicate that these cannot be utilized interchangeably. In conclusion, poor correlation between the six objective individual typology angle categories and the subjective Fitzpatrick skin phototype categories was established along with highlighting ITAs potential in photobiologic studies and objective standardization of skin type classifications.

Development and validation of the fingertip unit for assessing Facial Vitiligo Area Scoring Index.

BACKGROUND: Facial involvement of vitiligo is an important factor in a patient's life and has often been evaluated separately from body surface area in clinical trials. However, no reliable tools to measure facial vitiligo specifically are available thus far. OBJECTIVE: To develop and validate a practical instrument for assessing facial vitiligo. METHODS: The ratios of a hand to a fingertip unit (FTU) of 98 healthy volunteers (age range, 2-69 years) were calculated to define the FTU. Facial Vitiligo Area Scoring Index was measured as the sum of all FTUs of each vitiligo lesion on the face (range, 0-112 FTU). In the validation study, 6 raters evaluated 11 patients with facial vitiligo twice at an interval of 2 weeks. RESULTS: One hand was measured at 32.1 ± 1.3 FTU, which was highly consistent among subjects across different age groups, sexes, and races. Facial Vitiligo Area Scoring Index showed remarkably high accuracy (concordance correlation coefficient, 0.946; smallest detectable change, 2.2 FTU) as well as high intrarater reliability (intraclass correlation coefficient, 0.903; inter-rater reliability, 0.903). LIMITATIONS: Lack of dynamic validation of responsiveness. CONCLUSION: Facial Vitiligo Area Scoring Index using the FTU is an intuitive, precise, and reliable instrument for assessing the extent of facial involvement in vitiligo patients.

Recommendations for Reporting Methods in Phototesting Studies.

The figure presented here illuminates the large number of variables that are necessary to adequately describe phototesting protocols. Each of these characteristics can be critical in understanding results presented in the photomedicine community as well as the broader photobiology and photochemistry communities. The inclusion of all of these variables within each phototesting publication will aid in discourse and further scientific discovery within our field.