SPF 50 Sunscreen Improves Dermis Echogenicity and Reduces Redness

SPF 50 sunscreen with high antioxidant potential used for 15 days reduces the reddish skin subtone and improves dermis echogenicity, according to study findings published in the Journal of Cosmetic Dermatology.

Researchers aimed to assess the effect of SPF 50 sunscreen with high antioxidant capacity in young men without photoprotection habits.

They conducted an experimental study in Ribeirão Preto, Brazil, that included 40 participants (100% men; age range 18 to 28 years) of whom 36 were without previous photoprotection habits. Individuals who smoked, had been treated with isotretinoin, were diagnosed with skin diseases or with hypersensitivity to cosmetic products were excluded. Individuals with surgeries or aesthetic procedures within the previous year were also excluded. Erythema was assessed for each participant using a visual score and skin colorimeter. Researchers obtained macroscopic images, and dermis echogenicity was assessed with high-frequency ultrasonography.

Various sunscreen formulations were employed, including methylene bis-benzotriazolyl tetramethylbutylphenol 6%, bisethylhexyloxyphenol methoxyphenyl triazine 6%, and octyl metoxicinamate 6%. Butylated hydroxytoluene 0.05% was used as the antioxidant. This study was conducted in autumn when the UV index was 6 to 10.

SPF 50 sunscreen was supplied to all participants with instructions to use at least once daily for 15 days, applying to the face before daily sun exposure. The number of daily applications, and the weight and/or volume of the sunscreen application were not regulated.

All participants reported applying a thin layer of sunscreen covering the facial region before direct sun exposure daily, and reported no reapplication during the day. Investigators noted that 86% of participants believed their skin was softer and less reddish.

It was noted that visual nonhomogeneous indications of erythema in the malar and nasal regions were present in all participants without photoprotection habits. Macroscopic images allowed researchers to observe an increase in the reddish skin tone in these same participants, as well as an increase in telangiectasias, both indicating the photoaging process.

Study authors found the colorimeter results were highly correlated with the visual score (r=0.8657). They were able to visually observe a reduction in superficial reddening of the skin. Improvement was noted in dermis echogenicity which they believe was correlated with the reduction in inflammation.

They found skin hydration and skin barrier parameters did not change.

“Utilization of a SPF 50 sunscreen with high antioxidant potential allows for a reduction in the reddish skin subtone and improve(s) the dermis echogenicity after 15 days of usage,” investigators concluded. They wrote, “We observed a quick improve(ment) in some skin parameters, however, it was not enough to improve the skin barrier.”