Summer and spring elbow rashes is a variant of polymorphous light eruption: confirmation by photoprovocation and histopathology in a series of five cases.

Background: Summer and spring eruptions on the elbows are a variant of polymorphous light eruption described on clinical and histopathological grounds; however, to our knowledge, they have not been confirmed by photobiological studies. Objective: Based on photobiological studies, this study aimed to demonstrate the involvement of ultraviolet-A (UVA) radiation in this variant of polymorphous light eruption occurring exclusively on the elbows. Methods: A series of five patients with polymorphous light eruption lesions on the elbows were included in our study. All patients underwent phototesting and photoprovocation of the skin lesions after exposure to a UVA light source [Philips UVA HPA lamp (400 W)]. All patients underwent punch biopsy and histopathological and immunohistochemical studies with anti-CD123. Results: In all the cases, UVA irradiation caused the appearance of skin lesions on the elbows with characteristic polymorphous light eruption. Histological data showed edema in the superficial dermis and a perivascular lymphocytic infiltrate compatible with polymorphous light eruption. Immunohistochemical staining for CD1-23 showed negative results. Conclusions: For the first time, photobiological photoprovocation studies demonstrated that repeated exposure to UVA radiation leads to the generation of skin lesions on the elbows, which are clinically and histologically consistent with summer and spring eruptions, confirming that elbow rash is a variant of polymorphous light eruption.

Correlation between UV Index, Temperature and Humidity with Respect to Incidence and Severity of COVID 19 in Spain.

BACKGROUND: Various studies support the inverse correlation between solar exposure and Coronavirus SARS-CoV-2 infection. In Spain, from the Canary Islands to the northern part of the country, the global incidence of COVID-19 is different depending on latitude, which could be related to different meteorological conditions such as temperature, humidity, and ultraviolet index (UVI). The objective of the present work was to analyze the association between UVI, other relevant environmental factors such as temperature and humidity, and the incidence, severity, and mortality of COVID-19 at different latitudes in Spain. METHODS: An observational prospective study was conducted, recording the numbers of new cases, hospitalizations, patients in critical units, mortality rates, and annual variations related to UVI, temperature, and humidity in five different provinces of Spain from January 2020 to February 2021. RESULTS: Statistically significant inverse correlations (Spearman coefficients) were observed between UVI, temperature, annual changes, and the incidence of COVID-19 cases at almost all latitudes. CONCLUSION: Higher ultraviolet radiation levels and mean temperatures could contribute to reducing COVID-19 incidence, hospitalizations, and mortality.

Ultraviolet exposure of competitors during a Tokyo Olympic Sailing Regatta Test Event.

BACKGROUND: Overexposure to sunlight is the main cause of skin cancer. Photoprotection practices and sunburn play a crucial role in skin cancer prevention. OBJECTIVES: This study aimed to quantify the risk of sun exposure and to evaluate photoprotection practices in Spanish sailors during Olympic competitions. METHODS: Solar daily ultraviolet (UV) radiation cycle, personal UV dosimetry, photoprotection practices and sunburn checking were followed during three consecutive days of competition among sailors from the Spanish Olympic Sailing Team during a Tokyo Olympic Regatta Test Event. RESULTS: A total of 13 sailors (7 women), with mean age of 27.6 ± 4.7 years and sports experience of 17.7 ± 5.4 years, were studied. The most common phototypes were type III (53.8%) and type II (38.5%). The rate of sunburn checked was high (46.2%). The mean daily personal UV exposure received was 761.0 ± 263.6 J/m2 , 3.0 ± 1.1 minimal erythemal dose and 7.6 ± 2.6 standard erythemal dose, seven times greater than the maximum permissible UV light exposure values for an 8 h working day. The use of a T-shirt was the most common practice (94.2%), followed by the use of shade (50.2%), hat/cap (44.0%), sunglasses (26.1%) and sunscreen (11.8%). CONCLUSIONS: Olympic sailor's studies presented high levels of UV radiation received, high rate of sunburn and insufficient adherence to sun-protective behaviours (especially, to use of sunscreen) to prevent sunburn, the main cause of skin cancer. Sport Federations should develop educational campaigns addressing sun-related exposure habits and photoprotection behaviours to reduce the risk of skin cancer among these athletes.

The potential role of UV and blue light from the sun, artificial lighting, and electronic devices in melanogenesis and oxidative stress.

Our exposure to blue light from artificial sources such as indoor lights (mainly light-emitting diodes [LEDs]) and electronic devices (e.g., smartphones, computer monitors, and television screens), has increased in recent years, particularly during the recent coronavirus disease 2019 lockdown. This radiation has been associated to skin damage across its potential in generating reactive oxygen species in both the epidermis and the dermis, skin water imbalances and of potential activating melanin production. These circumstances make it important to determine whether current blue light exposure levels under artificial illumination and electronic devices exposure can cause the previously indicated disorders as compared to solar UV and visible radiation in a typical summer day. Blue light accounted for 25% of the sun's rays, approximately 30% of radiation emitted by electronic devices, and approximately from 6% to 40% of that emitted by indoor lights. The reference equations showed that the sun was the main source of effective irradiance for immediate and persistent pigmentation as well as for potential oxidative stress in our skin. Effective blue light exposure to artificial devices is significantly lower than the solar contribution. However, its contribution must be considered as accumulative dose effect, and especially in people with hypersensitivity promoting skin hyperpigmentation.

Analysis and evaluation of the operational characteristics of a new photodynamic therapy device.

One of the key aspects of photodynamic therapy is the light source that is used to irradiate the lesion to be treated. The devices used must ensure that their emission spectrum matches the absorption spectrum of the photosensitizer, so that treatment radiation is delivered only on the target area, without irradiating healthy tissue at superficial or deep levels. Irradiance values must be adequate in order to avoid thermal damage, exceed the oxygen replenishment rate and avoid long treatment times. Furthermore, the device should be user-friendly, inexpensive, and able to be adapted to different photosensitizers. We have developed an easy-to-use and highly customizable device based on LED technology. Its innovative geometric design allows radiation to be delivered to a small treatment surface, since the LEDs are arranged in three arms, the configuration of which directs their radiation on the treatment point. Different high-power color LEDs are disposed on the arms, and can be independently selected based on the most effective wavelengths for exciting the different photodynamic therapy photosensitizers. We have tested the prototype in 5 different patients (1 actinic keratose, 1 actinic cheilitis, 1 superficial basal cell carcinoma and 2 Bowen's disease) and after 1-2 sessions of total cumulative dose of 25-50 J / cm2, 100% clearance of lesions were obtained. Our device can be used by any professional in the field, whether for medical or research purposes. It facilitates the development of treatment protocols and trials with different photosensitizers.

Booster Effect of a Natural Extract of Polypodium leucotomos (Fernblock®) That Improves the UV Barrier Function and Immune Protection Capability of Sunscreen Formulations.

Background: Novel approaches to photoprotection must go beyond classical MED measurements, as discoveries on the effect of UV radiation on skin paints a more complex and multi-pronged scenario with multitude of skin cell types involved. Of these, photoimmunoprotection emerges as a crucial factor that protects against skin cancer and photoaging. A novel immune parameter is enabled by the precise knowledge of the wavelength and dose of solar radiation that induces photoimmunosupression. Natural substances, that can play different roles in photoprotection as antioxidant, immune regulation, and DNA protection as well as its possible ability as sunscreen are the new goals in cosmetic industry. Objective: To analyze the effect of a specific natural extract from Polypodium leucotomos (PLE, Fernblock®), as part of topical sunscreen formulations to protect from photoimmunosuppression, as well as other deleterious biological effects of UV radiation. Methods: The possible sunscreen effect of PLE was analyzed by including 1% (w/w) PLE in four different galenic formulations containing different combinations of UVB and UVA organic and mineral filters. In vitro sun protection factor (SPF), UVA protection factor (UVA-PF), contact hypersensitivity factor (CHS), and human immunoprotection factor (HIF) were estimated following the same protocol as ISO 24443:2012 for in vitro UVA-PF determination. Results: PLE-containing formulations significantly reduced UV radiation reaching to skin. Combination of UVB and UVA filters with PLE increased SPF and UVAPF significantly. PLE also increased UV immune protection, by elevating the contact hypersensitivity factor and the human immunoprotective factor of the sunscreen formulations. Conclusion: This study confirms the double role of PLE in photoprotection. Together to the biological activity shown in previous works, the UV absorption properties of PLE confers a booster effect when it is supplemented in topical sunscreens increasing the protection not only at level of erythema and permanent pigment darkening but also against two photoimmunoprotection factors.

Effect of Nail Thickness on Visible Radiation Transmittance: Implications for New Photodynamic Therapy Technologies in Onychomycosis.

Photodynamic therapy is taking importance as a nonintrusive treatment for nail onychomycosis. Knowledge of true transmittance values across nails could lead to qualitative and quantitative improvements in light-based treatments. We have characterized the spectral transmittance of healthy and fungally infected human fingernails and toenails according to nail thickness, and we propose a surface transmittance model for the small-scale optimization of light-based treatments. Transmittance of fingernails and toenails was analyzed by means of spectroradiometric measurements under solar-simulated visible light radiation (400 nm to 750 nm). The nail thickness was measured by means of microscope measurement. Transmittance was highest at longer wavelengths and decreased gradually as the wavelengths became shorter but with a significant nail transmittance of around 20% in the blue region of the spectrum. In the case of nails affected by onychomycosis, transmittance fell to under 10% because of the thickness of the nails, with no changes in spectral characteristics of transmitted light. Nail thickness is the main variable controlling exponentially light transmission in the visible spectrum and not only red radiation is effective for nail onychomycosis PDT. Blue light, the spectral band more effective for PPIX absorption is also effectively transmitted.

UVA and UVB Photoprotective Capabilities of Topical Formulations Containing Mycosporine-like Amino Acids (MAAs) through Different Biological Effective Protection Factors (BEPFs).

The safety and stability of synthetic UV-filters and the procedures for evaluating the photoprotective capability of commercial sunscreens are under continuous review. The influence of pH and temperature stressors on the stability of certain Mycosporine-like amino acids (MAAs) isolated at high purity levels was examined. MAAs were highly stable at room temperature during 24 h at pH 4.5⁻8.5. At 50 °C, MAAs showed instability at pH 10.5 while at 85 °C, progressive disappearances were observed for MAAs through the studied pH range. In alkaline conditions, their degradation was much faster. Mycosporine-serinol and porphyra-334 (+shinorine) were the most stable MAAs under the conditions tested. They were included in four cosmetically stable topical sunscreens, of which the Sun Protection Factor (SPF) and other Biological Effective Protection Factors (BEPFs) were calculated. The formulation containing these MAAs showed similar SPF and UVB-BEPFs values as those of the reference sunscreen, composed of synthetic UV absorbing filters in similar percentages, while UVA-BEPFs values were slightly lower. Current in vitro data strongly suggest that MAAs, as natural and safe UV-absorbing and antioxidant compounds, have high potential for protection against the diverse harmful effects of solar UV radiation. In addition, novel complementary in vitro tests for evaluation of commercial sunscreens efficacy are proposed.

Infrared radiation increases skin damage induced by other wavelengths in solar urticaria.

BACKGROUND: Photodermatoses are typically investigated by analyzing the individual or combined effects of ultraviolet A (UVA), ultraviolet B (UVB), and visible light using light sources that simulate portions of the solar spectrum. Infrared radiation (IRR), however, accounts for 53% of incident solar radiation, but its effects are not taken into account in standard phototest protocols. AIMS: The aim was to analyze the effects of IRR, alone and combined with UVA and visible light on solar urticaria lesions, with a distinction between infrared A (IRA) and infrared B (IRB). METHODS: We performed standard phototests with UVA and visible light in four patients with solar urticaria and also tested the effects after blocking IRB with a water filter. To analyze the direct effect of IRR, we performed phototests with IRA and IRB. RESULTS: Initial standard phototests that were all positive found the induction of erythema and whealing, while when IRR was blocked from the UVA and visible light sources, three of the patients developed no lesions, while the fourth developed a very small wheal. CONCLUSION: These results suggest that IRR has the potential to produce and exacerbate lesions caused by other types of radiation. Consideration of these effects during phototesting could help prevent diagnostic errors.

Human Hair as a Natural Sun Protection Agent: A Quantitative Study.

The rising incidence of skin cancers attributable to excessive sun exposure has become a major health concern worldwide. While numerous studies have analyzed the sun protective effect of sunscreens, clothing and antioxidants, none to date have measured the photoprotective effect of hair, despite clinical evidence that individuals with balding or thinning hair are at greater risk of skin lesions that can progress to cancer, hence the recommendation to use hats or umbrellas. We analyzed the level of protection offered by hair according to hair density, thickness and color using the spectral transmittance and corrected for relative erythema effectiveness. Our results show that hair provides a barrier against both UVB and UVA radiation which is significantly increased with respect to the hair density, thickness and the presence of melanins. This is the first study to quantify sun protection factor offered by hair, namely hair ultraviolet protection factor (HUPF). We believe that hair should be recognized as an important natural sun barrier in the prevention of UV-induced skin cancers.

New advances in protection against solar ultraviolet radiation in textiles for summer clothing.

Clothing is considered one of the most important tools for photoprotection against harmful solar ultraviolet radiation (UVR). The standard for sun-protective clothing is based on erythema despite other biological effects of UVR on the skin. We analyzed the potential protection against UVR in fabrics destined for summer clothing based on several action spectra. We examined 50 garments classified by type of fabric composition, structure of the fiber yarn and color. The ultraviolet protection factor was calculated based on fabric ultraviolet transmittance corrected for erythema according to the EU standard E-13758 as well as the UVA transmittance of fabrics. UVR protection was also analyzed in base of different action spectra as for previtamin D3, nonmelanoma skin cancer, photoimmunosuppression and photoaging. Most knitted fabrics used for sports T-shirts offered excellent ratings for ultraviolet protection while normal shirts showed very low ratings, particularly against photoaging. The cover is the most influential variable in fabric photoprotection, having an exponential relationship with the UPF. The relation between cover and UVA protection was linearly negative. Information about ultraviolet protection in textiles used for summer clothing should be included in labeling as some types of fabrics, especially those used for shirts, offer very low UVR protection.

Changes in photoinduced cutaneous erythema with topical application of a combination of vitamins C and E before and after UV exposure.

BACKGROUND: Ultraviolet radiation is harmful for human skin, and photodamaging pathologies such as actinic erythema, are formerly described as a consequence of UV direct effect on DNA and indirectly by local immune reactions. However, the degree of participation of oxidative stress in actinic erythema and the role of antioxidants in photoprotection are still not fully understood. OBJECTIVE: To evaluate the possible palliative role of a combination of the antioxidants vitamins C and E in human cutaneous erythema when applied topically before and after UV exposure. MATERIALS AND METHODS: The study included 20 volunteers of phototypes II, II-III and III with no solar exposure for two months prior to the study. The volunteers were submitted to a phototest consisting on the analysis of the minimal erythemal dose (MED) under different treatments: 1. Untreated irradiated skin; 2. Irradiated skin previously treated with vehicle; 3. Irradiated skin previously treated with a combination of vitamins (2.5% vit E-5% vit C); and 4. Skin treated with the antioxidant combination after irradiation. Cutaneous erythema was evaluated 24h after exposure and the MED was calculated for each treatment. RESULTS: The application of vehicle did not significantly affect the MED compared to untreated irradiated skin. Application of the antioxidant combination, prior to irradiation, increased the MED in all phototypes compared with untreated irradiated skin with an average increase of 36.9%. Antioxidants applied after exposure promoted an average increase of the MED by 19.8%. CONCLUSIONS: Combination of topical antioxidants (vitamins C and E) shows photoprotection activity against erythema, mainly owing to their high absorption properties. Moreover, their antioxidant activity could be considered as additive, and independent of their optical properties.