Daylight Photodynamic Therapy: At-Home Delivery.

This pilot study evaluated the design, usability, and practicality of the dPDT@home kit for treating actinic keratoses (AKs) on the face and scalp. The kit allowed patients to manage their treatment at home, reducing hospital visits and utilizing natural sunlight. While patients were very willing to use the kit again, further studies are required to evaluate outcomes and ascertain the need for additional improvements and support.

Artificial intelligence-based molecular property prediction of photosensitising effects of drugs.

Drug-induced photosensitivity is a potential adverse event of many drugs and chemicals used across a wide range of specialties in clinical medicine. In the present study, we investigated the feasibility of predicting the photosensitising effects of drugs and chemical compounds via state-of-the-art artificial intelligence-based workflows. A dataset of 2200 drugs was used to train three distinct models (logistic regression, XGBoost and a deep learning model (Chemprop)) to predict photosensitising attributes.

Continuum of light sensitivity in atopic dermatitis: A retrospective analysis of 139 cases in Scotland.

Background: Previous reports have characterized photosensitivity in atopic dermatitis (AD), but with differences in terminology and criteria.

Objective: This study aims to assess outcomes in 139 patients with AD referred for photodiagnostic testing and to establish diagnostic criteria for photosensitivity in AD.

Methods: Clinical and photodiagnostic data were reviewed, categorizing photosensitivity into photoexacerbated AD, photosensitive AD, and chronic actinic dermatitis.

Far-UVC: The impact of optical filters on real-world deployment.

In 2015, a study showed that Krypton-Chloride (KrCl) excimer lamps could induce erythema and basal layer DNA damage in human skin. Later studies found that filtering out longer wavelength emissions from these lamps resulted in no acute skin effects. However, there is a limited understanding of how much to reduce unwanted emissions and which wavelengths are important.

Potential harm to the skin from unfiltered krypton chloride 'far-ultraviolet-C' lamps, even below an occupational exposure limit.

Ultraviolet-C (UVC) radiation can effectively inactivate pathogens on surfaces and in the air. Due to the potential for harm to skin and eyes, human exposure to UVC should be limited within the guideline exposure limits produced by the International Commission on Non-Ionising Radiation Protection (ICNIRP) or the American Conference of Governmental Industrial Hygienists (ACGIHs). Both organisations state an effective spectrally weighted limit of 3 mJ cm, although the spectral weighting factors of the two organisations diverged following a revision of the ACGIH guidelines in 2022.

Insights into proton pump inhibitor-induced photosensitivity: An observational study in a tertiary photobiology service.

Background: Proton pump inhibitors (PPIs) are extensively prescribed but may cause photosensitivity and drug-induced lupus erythematosus (DILE), which can be overlooked as the drug may have been taken for years prior to presentation.

Methods: We reviewed the clinical and investigation findings of patients diagnosed with PPI-induced photosensitivity, diagnosed through the Scottish Photobiology Service.

Results: We report 11 patients with median age of onset 61-years and mean duration of PPI ingestion of 5-years [DILE ( = 6), phototoxicity ( = 3) and drug-induced solar urticaria through a lupus mechanism ( = 2)].

Athena speciality certificate examination case for photodermatology.

This Athena case describes a young girl with a 2-year history of episodic pruritic erythematous papules on her right cheek, which coalesced to form a plaque. The eruption later recurred, involving the left cheek, nose and upper arms.

Phototherapy for atopic eczema.

Background: Atopic eczema (AE), also known as atopic dermatitis, is a chronic inflammatory skin condition that causes significant burden. Phototherapy is sometimes used to treat AE when topical treatments, such as corticosteroids, are insufficient or poorly tolerated.

Objectives: To assess the effects of phototherapy for treating AE.

Depth Penetration of Light into Skin as a Function of Wavelength from 200 to 1000 nm.

An increase in the use of light-based technology and medical devices has created a demand for informative and accessible data showing the depth that light penetrates into skin and how this varies with wavelength. These data would be particularly beneficial in many areas of medical research and would support the use and development of disease-targeted light-based therapies for specific skin diseases, based on increased understanding of wavelength-dependency of cutaneous penetration effects. We have used Monte Carlo radiative transport (MCRT) to simulate light propagation through a multi-layered skin model for the wavelength range of 200-1000 nm.

Computer Modeling Indicates Dramatically Less DNA Damage from Far-UVC Krypton Chloride Lamps (222 nm) than from Sunlight Exposure.

This study aims to investigate, with computer modeling, the DNA damage (assessed by cyclobutane pyrimidine dimer (CPD) formation) from far-ultraviolet C (far-UVC) in comparison with sunlight exposure in both a temperate (Harwell, England) and Mediterranean (Thessaloniki, Greece) climate. The research utilizes the published results from Barnard et al. [Barnard, I.

Global verification of a model for determining daylight photodynamic therapy dose.

Daylight photodynamic therapy is an effective treatment for actinic keratoses and relies on a minimum PpIX-effective light exposure dose being delivered during treatment. As such, daylight dosimetry is an important aspect of this treatment. Relatively simple measurements of illuminance may be converted to PpIX-effective irradiance, and subsequently exposure dose, via a conversion model (the O'Mahoney model).

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.

Development of a Predictive Monte Carlo Radiative Transfer Model for Ablative Fractional Skin Lasers.

It is possible to enhance topical drug delivery by pretreatment of the skin with ablative fractional lasers (AFLs). However, the parameters to use for a given AFL to achieve the desired depth of ablation or the desired therapeutic or cosmetic outcome are hard to predict. This leaves open the real possibility of overapplication or underapplication of laser energy to the skin.

Research Techniques Made Simple: Experimental UVR Exposure.

UVR exposure is a widely applied technique in clinical and preclinical studies. Such experimental conditions provide crucial information on the biological responses of skin and cell models, which may then be extrapolated and interpreted, for example, in the context of equivalent daylight exposures. It is therefore important to fully understand the characteristics of UVR and the principles behind correct and appropriate UVR exposure in experimental settings.

Role of Hypotaurine in Protection against UVA-Induced Damage in Keratinocytes.

Photoageing and skin cancer are major causes of morbidity and are a high cost to society. Interest in the development of photoprotective agents for inclusion in topical cosmetic and sunscreen products is profound. Recently, amino acids with a sulfinic group, notably hypotaurine, have been included as ingredients in cosmetic preparations.

SmartPDT®: Smartphone enabled real-time dosimetry via satellite observation for daylight photodynamic therapy.

Background: Actinic keratosis (AK) affects one quarter of over 60  year olds in Europe with the risk of transforming into invasive squamous cell carcinoma. Daylight photodynamic therapy (dPDT) is an effective and patient preferred treatment that uses sunlight to clear AK. Currently, there is no standardised method for measuring the light received during treatment.