Modern approaches to photoprotection.

Ultraviolet (UV) light reacts with skin to produce changes, including photoaging and skin cancer. Sunscreen strategies are useful for protection against UVB (290-320 nm) and short-wave UVA (320-340 nm), but complete protection against long-wave UVA (340-400 nm) has not been achieved. Because UVA is especially efficient at generating reactive oxygen species, it is increasingly recognized as an important cause of photoaging changes and skin cancer. A systemic strategy capable of protecting all skin has not been achieved, although a combination of high-dose oral vitamin C and E can provide modest photoprotection. Topical antioxidants are a useful complement to sunscreens; when delivered into skin, they provide a supplemental reservoir for inherent antioxidants and afford additional photoprotection.