Risks and Benefits of UV Radiation.

While UV radiation is a skin carcinogen, this should not obscure the growing evidence that sunlight has significant health benefits, including impacts on cardiovascular and metabolic health. Epidemiological and mechanistic evidences for the importance of different wavelengths of sunlight, including blue light and UV radiation, are presented.

Extreme Exposure to Filtered Far-UVC: A Case Study†.

Far-UVC devices are being commercially sold as "safe for humans" for the inactivation of SARS-CoV-2, without supporting human safety data. We felt there was a need for rapid proof-of-concept human self-exposure, to inform future controlled research and promote informed discussion. A Fitzpatrick Skin Type II individual exposed their inner forearms to large radiant exposures from a filtered Krypton-Chloride (KrCl) far-UVC system (SafeZoneUVC, Ushio Inc., Tokyo, Japan) with peak emission at 222 nm. No visible skin changes were observed at 1500 mJ cm-2 ; whereas, skin yellowing that appeared immediately and resolved within 24 h occurred with a 6000 mJ cm-2 exposure. No erythema was observed at any time point with exposures up to 18 000 mJ cm-2 . These results combined with Monte Carlo Radiative Transfer computer modeling suggest that filtering longer ultraviolet wavelengths is critical for the human skin safety of far-UVC devices. This work also contributes to growing arguments for the exploration of exposure limit expansion, which would subsequently enable faster inactivation of viruses.

Low-Dose Hypofractionated Total Skin Electron Beam Therapy for Adult Cutaneous T-Cell Lymphoma.

PURPOSE: Historically, the standard of care for total skin electron beam therapy (TSEBT) delivered 30 to 36 Gy over 5 to 10 weeks. Given the high risk of relapse, a majority of patients require additional treatments. Therefore, attempts to use a shortened course of TSEBT have been investigated. METHODS AND MATERIALS: We conducted a single-institution retrospective review to evaluate disease response, control, and toxicity using a low-dose, hypofractionated course of TSEBT (HTSEBT) in patients with mycosis fungoides. RESULTS: Forty patients received 57 courses of HTSEBT. Median dose (Gy)/fractionation was 12/3, spanning a median time of 2.4 weeks. Overall response rate of patients assessed (n = 54) was 100%. Thirty-one courses (57.4%) resulted in a complete response and 23 courses (42.6%) resulted in a partial response. Cumulative incidence of progressive skin disease at 3 months was 37.2%, at 6 months, 56.9%, and at 1 year, 81.5%. Of the 40 patients treated with a first course of HTSEBT, 31 received subsequent courses of radiotherapy. Cumulative incidence of subsequent treatment was 28.0% at 3 months, 46.8% at 6 months, and 70.0% at 1 year. Patients who underwent repeat courses of HTSEBT continued to have similar treatment responses to repeat courses without increased toxicities. Toxicities from all courses were acceptable with the exception of 1 patient, who experienced grade 4 skin toxicity (moist desquamation requiring hospitalization). CONCLUSIONS: Low-dose HTSEBT provides good palliation in patients with cutaneous T-cell lymphoma with a satisfactory response and toxicity profile. HTSEBT allows therapy to be completed in far fewer treatments. Low-dose HTSEBT is an appropriate treatment option for patients unable to come for daily treatment. HTSEBT provides a way to decrease exposure to other patients and staff during public health emergencies such as the coronavirus disease 2019 (COVID-19) pandemic.

Harmless Effects of Sterilizing 222-nm far-UV Radiation on Mouse Skin and Eye Tissues.

In this issue, Yamano et al. provide further evidence that germicidal 222-nm far UV light has no immediate and delayed harmful effects on the skin and ocular tissue of rats. The safety of 222-nm krypton-chlorine excimer lamps, highlighted in the commentary article, has already received relevant applications in the treatment of surgical site infections and in the control of airborne and foodborne pathogens.

Resumption of laser/IPL skin services post COVID-19 lockdown-British Medical Laser Association (BMLA) guidance document.

The COVID-19 pandemic has had a significant negative impact on the global health economies. As health care resources have been prioritised to cater for patients affected by COVID-19, routine health care services have remained suspended. In an effort to slow the spread of SARS-CoV-2 virus, the UK introduced a country-wide lockdown which came into effect on the 23rd March 2020. Since then, clinics offering laser and intense pulsed light services have remained closed for business. As the rate of COVID-19 infection slows, the UK government has issued guidance for lifting of the lockdown in a cautious and phased manner. With this in view and to facilitate safe resumption of laser and intense pulsed light services, the British Medical Laser Services has issued this guidance document, based on best available and current scientific evidence.