Greater efficacy of SPF 100+ sunscreen compared to SPF 50+ in sunburn prevention during five consecutive days of sunlight exposure: A Randomized, Double-Blind Clinical Trial
Recommended Citation
Kohli I, Nicholson CL, Williams JD, Lyons AB, Seo I, Maitra P, Tian X, Atillasoy E, Lim HW, and Hamzavi IH. Greater efficacy of SPF 100+ sunscreen compared to SPF 50+ in sunburn prevention during five consecutive days of sunlight exposure: A Randomized, Double-Blind Clinical Trial. J Am Acad Dermatol 2019.
Document Type
Article
Publication Date
9-19-2019
Publication Title
J Am Acad Dermatol
Abstract
BACKGROUND: Beach vacations are high-risk settings for overexposure to ultraviolet (UV) radiation.
OBJECTIVE: To compare the sunburn protective efficacy of SPF 50+ and SPF 100+ sunscreens under actual use at the beach METHODS: A prospective, randomized, double-blind, single-center, split body/face study of 55 healthy subjects. Each subject applied both sunscreens to randomized side of the face/body for up to 5 consecutive days. Blinded clinical evaluation of erythema by a single grader and objective instrumental assessments, colorimetry and diffuse reflectance spectroscopy, were performed the morning following each sun-exposure.
RESULTS: After five days, 31 (56%) subjects had more sunburn on the SPF 50+ side and 4 (7%) on the SPF 100+ side. Overall, mean erythema intensity demonstrated statistically significantly less erythema on the SPF 100+ side compared to SPF 50+. The first observation of sunburn exclusively on the SPF 50+ side occurred after one day whereas that for SPF 100+ occurred after three days of sun-exposure.
LIMITATIONS: Only initial sunscreen application was monitored, only one skin-phototype I subject was recruited, and subjects were recruited from local beach area.
CONCLUSION: SPF 100+ was significantly more effective in protecting against UV-induced erythema and sunburn than SPF 50+ in actual use within a beach vacation setting.
PubMed ID
31542406
ePublication
ePub ahead of print
