Nneamaka Ezekwe, Aunna Pourang, Alexis B Lyons, Shanthi Narla, Amruth Atyam, Shereen Zia, Ben J Friedman, Iltefat H Hamzavi, Henry W Lim, Indermeet Kohli
BACKGROUND: Long wavelength ultraviolet-A1 in combination with visible light induces hyperpigmentation, particularly in dark-skin phototypes. This study evaluated the efficacy of four sunscreen formulations in protecting against VL + UVA1 (370-700 nm). METHODS: The test products (A-D) were applied to the back of 12 volunteers, then irradiated with 320 J/cm2 VL + UVA1 (3.5% UVA1 [370-400 nm]). Immediately after irradiation, and at Days 1, 7, and 14, erythema and pigmentation were assessed by investigator global assessment (IGA), colorimetry (Δa* and ΔITA) and diffuse reflectance spectroscopy (DRS)-measured relative dyschromia (area under the curve AUC)...
December 8, 2023: Photodermatology, Photoimmunology & Photomedicine