31962 Effects of blue light on the skin and its therapeutic uses: Photodynamic therapy and beyond

Background: Blue light is the most energetic portion of the visible light spectrum, emitting between the wavelengths of 400-500 nm. Recent awareness of its ubiquity and potential has led to greater developments in therapeutic uses. Methods: A Medline via PubMed, Embase, and Cumulative Index of Nursing and Allied Health (CINAHL) search for peer-reviewed articles published between 2010-2021 was performed utilizing PRISMA guidelines for articles related to blue light’s effect on the skin and therapeutic modalities utilizing blue light. This search resulted in 223 unique results, with 65 articles selected for the purpose of review. Results: While blue light is biologically active in the skin, it is to a much lesser degree than ultraviolet light. Therapeutic modalities utilizing blue light have been proven to be effective as monotherapy or a component of a comprehensive treatment plan for common dermatologic diseases such as actinic keratosis, acne, cutaneous infections, and psoriasis, and early reports support its use in DSAP and actinic cheilitis. Conclusions: The benefits and treatment applications of blue light have proven effective in multiple forms and uses. In the correct setting, it can be a useful tool to the practicing dermatologist for many common and sometimes refractory skin diseases while remaining low-risk and convenient. Further standardization and monitoring should be pursued to determine the most appropriate use.