Aging and photoaging

Skin aging is not a unique phenomenon but it is commonly divided into two different processes: chronological aging and photo-aging. Therefore we recognise two different phenotypes of skin aging. Chronological aging represents the structural, functional and metabolic changes in the skin that parallel the aging and degenerative changes in other body organs. Photo-aging is a consequence of oxidative damage due to overexposure to ultraviolet (UV) sunlight both UVA and UVB (responsible for sunburn, basal and squamous cell carcinoma). Conditions of variable UV exposure may result from different latitudes, alteration of atmosphere, job (farmer towards bank employer), different behaviour to sun bathing [1]. A lot of different theories have been proposed to explain the phenomenon of aging. Many of them are interlinked. The deceleration of the mortality rate is one of the most intriguing recent findings in longevity research.