Introduction
The inevitable process of aging begins at the time of birth.With maturity, the features of intrinsic or chronological aging become apparent. The cutaneous manifestations of chronological aging are manifold and include a smooth, pale appearance of the skin with fine wrinkling and loss of hydration [1]. The characteristics of intrinsic aging are often overshadowed by those of photoaging. Photoaging, aging of the skin induced by repeated exposures to ultraviolet (UV) light, leads to dramatic changes in the skin. These differences are highlighted by twin studies performed by New York City plastic surgeon Dr. Darrick E. Antell in which one twin with a significant sun exposure history displayed dramatic wrinkling compared with her sun-protected twin (Fig. 3.1a,b). Clinical characteristics of photoaging include fine and coarse wrinkling, roughness, dryness, telangiectasia, | | Figs. 3.1a,b. The manifestations
of photoaging after repeated
exposures to ultraviolet light are
highlighted by twin studies
performed by New York City
plastic surgeon Dr. Darrick
E.Antell in which one twin with a
significant sunexposure history
displays dramatic wrinkling (a)
compared with her
sun-protected twin (b) | cancerous lesions, precancerous lesions, and pigmentary alterations. Pigmentary alterations are a major component of photoaged skin and may be observed all skin types [2]. Pigmentary alterations associated with photoaged skin are of several varieties, including hypermelanosis as well as hypomelanosis. Mottled hyperpigmentation, ephelides, lentigines, and pigmented seborrheic keratoses are the primary lesions of hypermelanosis. Guttate hypomelanosis,presenting as white spots, is the primary manifestation of hypomelanosis associated with aged skin.
Intrinsic aging occurs universally in individuals of all racial and ethnic groups and with all skin types. In contrast, there is variability in the severity and manifestations of photoaging in Asians, | | | | | | | Core Messages -
Several mechanisms and mediators appear to control human aging, including longevity genes, cell death mediated by telomere shorting, and free radical activation. -
Clinical characteristics such as pigmentary changes and photoaging overshadow those of intrinsic aging. Pigmentary changes are major components of photoaging in the major skin types, including Asian,African American, and Caucasian. -
Intrinsic aging is marked by atrophy of the epidermis and dermis whereas photoaging is marked by dysplasia of epidermal cells, melanocyte heterogeneity, and elastosis of the dermis. -
Features of photoaging, including pigmentary changes, may be prevented by limiting ultraviolet (UV) light exposure. -
Use of sunscreen to block both UVA and UVB light is an important preventative measure. -
Antioxidants most likely play a role in the prevention of photoaging. | | | | | | | |
