The Taylor et al. study in this issue suggests that long-term hormone replacement therapy helps prevent skin aging. All patients interested in preventing skin aging should regularly use sunscreens, retinoids, and oral or topical antioxidants.

The requirements on sunscreens have essentially changed, since some years ago it was demonstrated that approximately 50% of free radicals, that are formed in the skin by solar radiation, originate from the visible and infrared regions of the solar spectrum. In addition, a critical radical concentration threshold could be found. If this concentration, the free radical threshold value (FRTV), is ...

The concept of the sun protection factor was originally proposed by the Austrian scientist Franz Greiter and subsequently adopted by many regulatory authorities and the cosmetic and pharmaceutical industries. It is popularly interpreted as how much longer skin covered with sunscreen takes to burn compared with unprotected skin. This interpretation can encourage users to prolong their sun exposu...

Distribution of Japanese skin types (JSTs), sun-exposure habits, and sunscreen use were surveyed in 379 new outpatients. The largest number of subjects belonged to JST class J-II (65%), J-I was second (24%), and J-III was third (11%). Eighty-eight percent of those studied had occasional or habitual sun exposure during the summer, and many were exposed for more than three hours per exposure day ...

Topical sunscreens contain molecules or molecular complexes that can absorb, reflect, or scatter UV photons. Evaluation of the efficacy of sunscreen products has been made through the Sun Protection Factor (SPF), a mean of quantitatively assessing in vivo the degree of protection offered by sunscreen products against solar radiation. In vivo evaluation of SPF has several drawbacks. First of all...

Titanium dioxide (TiO(2)) nanoparticles are extensively used today in sunscreens and coatings as protective compounds for human skin and material surfaces from UV radiation. In this paper, such particles are investigated by electron paramagnetic resonance spectroscopy as sources of free radicals under UV irradiation. The surface density of a placebo with embedded particles corresponds to the re...

Sun exposure is today well recognized as having an adverse effect on human skin. Part of sun radiation, ultraviolet radiation A (UVA) and B (UVB), can modify skin structures and induce short-term skin changes (sunburn, tanning, hyperkeratinization, brown spots) and long-term skin damages (accelerated skin aging and skin cancers). Protection against both UVA and UVB is very important, therefore ...

Conflicts of interest: The authors declare no conflict of interests. mineral sunscreens was tolerated. A repeated open application test on his forearm with the sunscreen products had produced a skin reaction, even without specific sun exposure [however, the site had not been covered with ultraviolet (UV)-protective textile, so photo-allergy could not be excluded]. The patient remembered having ...