Beach vacations are high-risk settings for overexposure to ultraviolet radiation.
To compare the sunburn protective efficacy of SPF 50+ and SPF 100+ sunscreens under actual use at the beach.
A prospective, randomized, double-blind, single-center, split-body/face study of 55 healthy individuals. Each participant applied both sunscreens to randomized sides 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 after each sun exposure.
After 5 days, 31 (56%) participants had more sunburn on the SPF 50+ side compared to 4 (7%) on the SPF 100+ side. Overall, mean erythema intensity showed statistically significantly less erythema on the SPF 100+ side compared with the SPF 50+ side. The first observation of sunburn exclusively on the SPF 50+ side occurred after 1 day of sun exposure, whereas that for SPF 100+ occurred after 3 days of sun exposure.
Only initial sunscreen application was monitored, only 1 participant with skin phototype I was recruited, and participants were recruited from a local beach area.
SPF 100+ was significantly more effective in protecting against ultraviolet radiation–induced erythema and sunburn than SPF 50+ in actual use in a beach vacation setting.Le texte complet de cet article est disponible en PDF.
Key words : beach, clinical research, general dermatology, medical dermatology, prevention, SPF, sun protection factor, sunlight, sunscreen, vacation
Abbreviations used : a*, CI, DRS, HbO2, SPF, SPT, UPF, UV
| Supported by Johnson & Johnson Consumer Inc. The funding source was involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
| Disclosure: This protocol was designed by the Henry Ford Hospital Department of Dermatology with a fee for protocol development paid to the institution by Johnson & Johnson. Dr Kohli is an investigator for Ferndale, Estee Lauder, Unigen, Johnson & Johnson, Allergan, and Bayer and is a consultant for Pfizer, Johnson & Johnson, and Bayer. Dr Lyons is a subinvestigator for Estee Lauder, Unigen, and Bayer. Dr Lim is an investigator for Estee Lauder, Ferndale, Unigen, and Incyte; is a consultant for Pierre Fabre and ISDIN; and has served as a speaker in an educational session sponsored by Pierre Fabre and Eli Lilly. Dr Hamzavi is an investigator for Estee Lauder, Ferndale, Unigen, Johnson & Johnson, Bayer, Allergan, and Incyte and is a consultant for Pfizer, Johnson & Johnson, and Bayer. Drs Williams, Seo, Maitra, and Atillasoy and Mr Tian are fulltime employees of Johnson & Johnson Consumer Inc. Dr Nicholson has no conflicts of interest to declare.
| Partial results of this study were presented in poster format at the American Academy of Dermatology Annual Meeting, Orlando, FL, March 2017, and at the American Academy of Dermatology Annual Meeting in San Diego, CA, March 2018.
| IRB approval status: Reviewed and approved by IRB Services (Aurora, Ontario, Canada).