Impact of Long‐Wavelength Ultraviolet A1 and Visible Light on Light‐Skinned Individuals

• Published in: Photochemistry and photobiology Vol. 95; no. 6; pp. 1285 - 1287
• Main Authors: Kohli, Indermeet, Zubair, Raheel, Lyons, Alexis B., Nahhas, Amanda F., Braunberger, Taylor L., Mokhtari, Mohsen, Ruvolo, Eduardo, Lim, Henry W., Hamzavi, Iltefat H.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.11.2019
• Subjects: Erythema; Irradiation; Skin cancer; Solar radiation; Solar spectra; Statistical analysis; Sun screens; Ultraviolet radiation; Wavelength
• ISSN: 0031-8655; 1751-1097; 1751-1097
• DOI: 10.1111/php.13143

Solar radiation is known to be a major contributor to the development of skin cancer. Most sunscreen formulations, including those with broad spectrum, offer minimal protection in long‐wavelength ultraviolet A1 (UVA1; 370–400 nm) and visible light (VL; 400–700 nm) domain. There is limited information regarding the impact of this broad waveband (VL + UVA1, 370–700 nm) on those with light skin. In this study, ten healthy adult subjects with Fitzpatrick skin phototypes I–III were enrolled. On day 0, subjects' lower back was exposed to a VL + UVA1 dose of 480 J cm−2. A statistically significant increase in erythema immediately after irradiation compared with subjects' baseline nonirradiated skin was observed. Clinically perceptible erythema with VL + UVA1 is a novel finding since the erythemogenic spectrum of sunlight has primarily been attributed to ultraviolet B and short‐wavelength ultraviolet A (320–340 nm). The results emphasize the need for protection against this part of the solar spectra and warrant further investigation. Solar radiation is known to be a major contributor to the development of skin cancer. Most sunscreen formulations, including those with broad spectrum, offer minimal protection in long wavelength ultraviolet A1 (UVA1; 370–400 nm) and visible light (VL; 400–700 nm) domain. There is limited information regarding the impact of this broad waveband (VL + UVA1, 370‐700 nm) on those with light skin. This study demonstrates that VL + UVA1 induces clinically perceptible erythema. This is a novel finding since the erythemogenic spectrum of sunlight has primarily been attributed to ultraviolet B and short wavelength ultraviolet A (320–340 nm).