The potential effect of Polypodium leucotomos extract on ultraviolet- and visible light-induced photoaging

Photoaging induced by both ultraviolet and visible light has been shown to lead to increased inflammation and dysregulation of the extracellular matrix. Standardized extract of the Polypodium leucotomos fern, PLE, possesses anti-inflammatory and antioxidant properties, and has been shown to potentially mitigate photoaging through various mechanisms. This comprehensive review presents the data available on the effects of P. leucotomos extract on UV and VL-induced photoaging in vitro as well as in vivo in murine and human models.

Assessment of Inter-rater Reliability of Clinical Hidradenitis Suppurativa Outcome Measures Using Ultrasonography

BACKGROUND

Hidradenitis suppurativa (HS) staging and severity is typically based upon physical examination findings which can result in misclassification of severity based on subclinical disease activity and significant variation between healthcare providers. Ultrasound (US) is an objective tool to help evaluate subclinical disease and more accurately classify severity of disease. The objective of this study was to evaluate inter-rater reliability in HS disease severity assessment using clinical and US techniques.

METHODS

Twenty subjects underwent clinical evaluation of HS using clinical outcome measures including Hurley, Sartorius, HS Physician Global Assessment (HS-PGA), and Hidradenitis Suppurativa Clinical Response (HiSCR) independently by two physicians. US was subsequently performed, and clinical assessments were repeated. Intra-class correlation coefficients (ICC) were obtained to evaluate inter-rater agreement of each outcome measure before and after US.

RESULTS

Pre- to post-US improvement in ICC was seen with the Sartorius, HiSCR nodule and abscess count, and HiSCR draining fistula count. The scores went from having "good" rater agreement for Sartorius and HiSCR nodule and abscess count and "poor" rater agreement for HiSCR draining fistula count to "excellent" rater agreement amongst these scores.

CONCLUSIONS

US improved inter-rater agreement and should be used in conjunction with physical examination findings to evaluate disease severity to ensure uniform staging.

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.

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.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.

Skin and eye protection against ultraviolet C from ultraviolet germicidal irradiation devices during the COVID-19 pandemic

With the COVID-19 pandemic depleting personal protective equipment worldwide, various methods including ultraviolet C (UVC) germicidal irradiation (UVGI) have been implemented to decontaminate N95 filtering facepiece respirators. These devices pose a risk for UVC exposure to the operator with reported adverse effects generally limited to the eyes and skin. Our hospitals are currently using UVC devices for N95 decontamination with a few reported cases of face and neck erythema from exposure. Because sunscreens are designed and tested for UVA and UVB protection only, their effects on blocking UVC are largely unknown. Therefore, our objective was to determine if various sunscreens, UV goggles, and surgical mask face shields minimize UVC exposure from UVGI devices. Our study clearly demonstrated that healthcare workers responsible for the disinfection of PPE using UVGI devices should always at least utilize clear face shields or UV goggles and sunscreen to protect against side effects of UVC exposure.

UVC Germicidal Units: Determination of Dose Received and Parameters to be Considered for N95 Respirator Decontamination and Reuse

The COVID-19 pandemic has resulted in an international shortage of personal protective equipment including N95 filtering facepiece respirators (FFRs), resulting in many institutions using ultraviolet germicidal irradiation (UVGI) technology for N95 FFR decontamination. To ensure proper decontamination, it is crucial to determine the dose received by various parts of the FFR in this process. Recently, our group customized a UVGI unit for N95 decontamination. With experimental and theoretical approach, this manuscript discusses the minimum dose received by various parts of the N95 respirator after one complete decontamination cycle with this UVGI unit. The results demonstrate that all parts of the N95 FFR received at least 1 J cm^-2 after one complete decontamination cycle with this unit. As there are a variety of UVGI devices and different types of FFRs, this study provides a model by which UVC dose received by different areas of the FFRs can be accurately assessed to ensure proper decontamination for the safety of healthcare providers.

Ultraviolet-C and other methods of decontamination of filtering facepiece N-95 respirators during the COVID-19 pandemic

During global health emergencies such as the current COVID-19 pandemic, the decontamination of single-use personal protective equipment (PPE) becomes a necessary means to keep up with the growing demand from healthcare workers and patients alike. Many unverified methods are being considered, which can pose the risk of incomplete decontamination and lead to catastrophic results. Several factors come into play when determining the suitability of such methods including the quality of the decontamination technique, the targeted pathogen, cost, ease of installation and use, rate of sterilization, and the surface or material to be sterilized. The germicidal properties of ultraviolet-C are well known. This review will cover the most commonly described methods for the sterilization of N95 respirators, namely, ultraviolet germicidal irradiation, hydrogen peroxide vaporization, microwave-generated steaming, and dry heating. These techniques have been tested previously and have demonstrated efficacy in reducing or inactivating viral and bacterial pathogens, although testing against SARS-CoV-2 specifically has not been done. Moreover, it must be emphasized that proper disposal after a single use is still ideal under normal circumstances.

Photoprotection beyond ultraviolet radiation: A review of tinted sunscreens

Ultraviolet radiation and visible light both have biologic effects on the skin. Visible light can induce erythema in light-skinned individuals and pigmentation in dark-skinned individuals. Broad-spectrum sunscreens protect against ultraviolet radiation but do not adequately protect against visible light. For a sunscreen to protect against visible light, it must be visible on the skin. Inorganic filters (also known as mineral filters), namely, zinc oxide and titanium dioxide, are used in the form of nanoparticles in sunscreens to minimize the chalky and white appearance on the skin; as such, they do not protect against visible light. Tinted sunscreens use different formulations and concentrations of iron oxides and pigmentary titanium dioxide to provide protection against visible light. Many shades of tinted sunscreens are available by combining different amounts of iron oxides and pigmentary titanium dioxide to cater to all skin phototypes. Therefore, tinted sunscreens are beneficial for patients with visible light-induced photodermatoses and those with hyperpigmentation disorders such as melasma and postinflammatory hyperpigmentation.

Quantitative measurement of skin surface oiliness and shine using differential polarized images

Excess amounts of skin surface oil can lead to adverse psychological consequences. Grease-spot photometry-based techniques measure sebum production rate. However, besides being tedious, these measurements are influenced by contact area, applied pressure, and time of application. Image analysis of polarized images has the potential to provide objective, quantitative information of skin oiliness. This study was designed to set up an imaging device for capturing and enhancing the changes in skin surface oiliness and to clinically and quantitatively, (via image analysis), evaluate varying levels of skin surface oiliness. Mineral oil was used to simulate skin surface oil. 40.5 µL of the mineral oil was applied within a two inch square area of interest on facial skin in twelve steps, from 1 to 40.5 µL, at 40% increments. The results indicate a strong correlation between the quantitative skin surface oiliness measurements and the clinical assessments. This sensitive technique has the potential to be utilized in future studies to evaluate product efficacies in reducing skin oiliness.

Visible light in photodermatology

Until recently, visible light (VL) had been regarded to be without significant photobiologic effect on the skin. Updated research suggests that this is not the case and the measurable effect of visible light on the skin is being documented in all skin types. Recent studies have demonstrated that in dark-skinned individuals, visible light can induce more intense and longer lasting pigmentation of the skin compared to UVA1. This effect was potentiated when VL was combined with a small percentage of ultraviolet A1 radiation (UVA1). Further, the combination of VL + UVA1 was also able to induce erythema in light-skinned individuals, a novel finding since the erythemogenic spectrum of sunlight had primarily been attributed to ultraviolet B (UVB) and short wavelength UVA (320-340 nm). Based on these findings, VL and UVA1 may also potentially play a role in conditions aggravated by sun exposure such as phototoxicity in light-skinned patients and post-inflammatory hyperpigmentation and melasma, especially in dark-skinned individuals. Currently available organic (chemical) UV filters are not sufficient to protect the skin from the effect of VL. VL is emerging as a key player in photodermatology and additional research is needed on the cutaneous effects of VL, as well as the development of filters and other means of photoprotection against the harmful effects of the VL spectrum. The aim of this manuscript is to review the literature on the cutaneous effects of VL as well as to highlight areas of dermatology where VL may play an important role.

Spectrum of virucidal activity from ultraviolet to infrared radiation

The COVID-19 pandemic has sparked a demand for safe and highly effective decontamination techniques for both personal protective equipment (PPE) and hospital and operating rooms. The gradual lifting of lockdown restrictions warrants the expansion of these measures into the outpatient arena. Ultraviolet C (UVC) radiation has well-known germicidal properties and is among the most frequently reported decontamination techniques used today. However, there is evidence that wavelengths beyond the traditional 254 nm UVC - namely far UVC (222 nm), ultraviolet B, ultraviolet A, visible light, and infrared radiation - have germicidal properties as well. This review will cover current literature regarding the germicidal effects of wavelengths ranging from UVC through the infrared waveband with an emphasis on their activity against viruses, and their potential applicability in the healthcare setting for general decontamination during an infectious outbreak.

The Role of Sunscreen in Melasma and Postinflammatory Hyperpigmentation

Photosensitive conditions such as melasma and postinflammatory hyperpigmentation (PIH) are exacerbated by exposure to ultraviolet (UV) rays and visible light making sunscreen use an essential component of treatment. This is especially true in skin of color patients who are less likely to use photoprotection, even if diagnosed with these photoexacerbated conditions. We aimed to evaluate the body of literature to provide evidence for the use of sunscreen in the treatment of melasma and PIH. We reviewed English articles from PubMed, Journals@Ovid Full Text, and Embase using the search terms “sunscreen” and either “melasma” “PIH,” or “post-inflammatory hyperpigmentation.” Nine relevant publications provide evidence that a broad spectrum of protection, including UVA, UVB, and visible light within sunscreens can play an adjuvant role in therapy for melasma and PIH by stabilizing and improving these pigmentary disorders in skin of color patients. This review illustrates the advantages and limitations of sunscreen use, as well as practice gaps in photoprotection in the skin of color patients with melasma and PIH.

Oral Polypodium Leucotomos Extract and Its Impact on Visible Light-Induced Pigmentation in Human Subjects

BACKGROUND: Visible light (VL) has multiple effects on the skin that currently available sunscreens do not protect against. Polypodium leucotomos extract (PLE) has properties that may offer protection against VL. OBJECTIVES: To determine the effectiveness of PLE in preventing VL-induced effects. METHODS: Twenty-two subjects with Fitzpatrick skin phototype IV-VI were enrolled. On day 0, subjects were irradiated with VL. Clinical Investigator’s Global Assessment (IGA) scoring and spectroscopic evaluations were performed immediately, 24 hours, and 7 days after irradiation. Subjects then received a 28-day supply of PLE (480 mg daily). Irradiation and evaluation were repeated. Three 4-mm punch biopsies were obtained for immunohistochemistry analysis: one from normal unirradiated skin and the other two twenty-four hours after irradiation, pre- and post-PLE, from sites irradiated with highest dose of VL. RESULTS: All subjects had immediate pigment darkening, persistent pigment darkening, and delayed tanning both pre- and post-PLE. For the highest VL dose (480 J/cm²) spectroscopic assessments demonstrated a statistically significant decrease in persistent pigment darkening and delayed tanning post-PLE. In addition, there was a significant decrease in cyclooxygenase-2, and a trend towards decreases in the markers for cellular damage post-PLE. While there was a trend towards lower IGA scores post-PLE, statistical significance was not reached possibly due to lack of sensitivity of the visual IGA scoring system in detecting small changes. CONCLUSIONS: Spectroscopic data and immunohistochemistry indicate an effect of PLE on visible light induced effects. As such, PLE may be used as an adjuvant to traditional means of photoprotection to protect against the effects of VL. Clinical trial registration number: NCT02904798. J Drugs Dermatol. 2019;18(12):1198-1203.

Standardizing serial photography for assessing and monitoring vitiligo: A core set of international recommendations for essential clinical and technical specifications

BACKGROUND

Clinical photography is an important component of the initial assessment and follow-up of patients with vitiligo in clinical practice and research settings. Standardization of this photographic process is essential to achieve useful, high-quality, and comparable photographs over time.

OBJECTIVE

The aim is to develop an international consensus for a core set of recommendations for standardized vitiligo clinical photography.

METHODS

Based an international meeting of vitiligo experts, a standard operating procedure was developed for vitiligo photography in daily practice and research settings. This protocol was subsequently reviewed by 20 vitiligo experts until agreement was reached.

RESULTS

The resulting protocol includes a set of 10 and 15 photographs for clinical practice and research purposes, respectively. The photographic series are based on anatomic units included in the Vitiligo Extent Score. Furthermore, graphic representations of standardized positioning and suggestions for guidelines to standardize the process (background color, lighting, position marking, scales, materials, instruments) for both color and ultraviolet photographs are described.

CONCLUSIONS

This consensus-based protocol for vitiligo photography will harmonize imaging for both clinical practice, translational research, and clinical trials. It can improve outcome assessment, foster multicenter collaboration, and promote better communication with patients regarding outcomes of treatment.

Long-wavelength Ultraviolet A1 and Visible Light Photoprotection: A Multimodality Assessment of Dose and Response

Human skin is exposed to visible light (VL; 400-700 nm) and long-wavelength ultraviolet A1 (UVA1) radiation (370-400 nm) after the application of organic broad-spectrum sunscreens. The biologic effects of these wavelengths have been demonstrated; however, a dose-response has not been investigated. Ten subjects with Fitzpatrick skin phototype IV-VI were enrolled. Subjects were irradiated with 2 light sources (80-480 J cm^-2 ): one comprising VL with less than 0.5% UVA1 (VL+UVA1) and the other pure VL. Skin responses were evaluated for 2 weeks using clinical and spectroscopic assessments. 4-mm punch biopsies were obtained from nonirradiated skin and sites irradiated with 480 J cm^-2 of VL+UVA1 and pure VL 24 h after irradiation. Clinical and spectroscopic assessments demonstrated a robust response at VL+UVA1 sites compared with pure VL. Histology findings demonstrated a statistically significant increase in the marker of inflammation (P < 0.05) and proliferation (P < 0.05) at the irradiated sites compared with nonirradiated control. Threshold doses of VL+UVA1 resulting in biologic responses were calculated. Results indicate that approximately 2 h of sun exposure, which equates to VL+UVA1 dose (~400 J cm^-2 ), is capable of inducing inflammation, immediate erythema and delayed tanning. These findings reinforce the need of photoprotection beyond the UV range.

Greater efficacy of SPF 100+ sunscreen compared with SPF 50+ in sunburn prevention during 5 consecutive days of sunlight exposure: A randomized, double-blind clinical trial

BACKGROUND

Beach vacations are high-risk settings for overexposure to ultraviolet radiation.

OBJECTIVE

To compare the sunburn protective efficacy of SPF 50+ and SPF 100+ sunscreens under actual use at the beach.

METHODS

A prospective, randomized, double-blind, single-center, split-body/face study of 55 healthy individuals. Each participant applied both sunscreens to randomized sides of the face/body for up to 5 consecutive days. Blinded clinical evaluation of erythema by a single grader and objective instrumental assessments, colorimetry, and diffuse reflectance spectroscopy were performed the morning after each sun exposure.

RESULTS

After 5 days, 31 (56%) participants had more sunburn on the SPF 50+ side compared to 4 (7%) on the SPF 100+ side. Overall, mean erythema intensity showed statistically significantly less erythema on the SPF 100+ side compared with the SPF 50+ side. The first observation of sunburn exclusively on the SPF 50+ side occurred after 1 day of sun exposure, whereas that for SPF 100+ occurred after 3 days of sun exposure.

LIMITATIONS

Only initial sunscreen application was monitored, only 1 participant with skin phototype I was recruited, and participants were recruited from a local beach area.

CONCLUSION

SPF 100+ was significantly more effective in protecting against ultraviolet radiation-induced erythema and sunburn than SPF 50+ in actual use in a beach vacation setting.

The dynamics of pigment reactions of human skin to ultraviolet A radiation

The pigment responses of human skin to broadband UVA radiation (320-400 nm) occur in three distinct phases. The first phase includes immediate pigment darkening (IPD), the pigment that appears immediately after irradiation. The second phase involves an intermediate step, termed persistent pigment darkening (PPD), which leads to the third phase of neomelanogenesis or delayed tanning (DT). Since DT results from synthesis of new melanin, it persists beyond 5-7 days. We conducted studies on human subjects to investigate the dynamic responses of the IPD and PPD reactions to broadband UVA radiation at threshold and superthreshold doses. The threshold doses for IPD, PPD, and DT were found to be approximately 1, 11, and 18 J/cm² , respectively. The colorimetry ΔL* value corresponding to minimal clinically perceptible pigmentation was found to be 0.8 ± 0.1. IPD appeared immediately and had an associated decay constant of approximately 1.4 minutes. At doses greater than PPD threshold, IPD reaction decayed while PPD developed indicating toward IPD being used as a substrate in the formation of PPD.