Aged Skin: A Study by Light, Transmission Electron, and Scanning Electron Microscopy

Robert M Lavker, Peishu Zheng, Gang Dong
1987 Journal of Investigative Dermatology  
The fine structural organization of the epidermis, der mal! epidermal junction, and dermis from an unexposed site (upper inner arm) of elderly people was compared with the organization of a similar region of young people. De spite an overall thinning of the epidermis and focal areas of cytologic atypia, the characteristic morphological mark ers associated with the keratinization process are not mark edly altered in appearance or amount. A well-formed stra tum corneum consisting offlattened,
more » ... leated horny cells enveloped by a thickened membrane, and intracellular spaces filled with electron-dense material provide structural evi dence that barrier ability is not compromised in senile skin. The dermal/epidermal changes in aged skin are marked and have significant physiologic implications. The major change is a relatively flat dermal/epidermal junction re sulting from the retraction of the epidermal papillae as well W ith advancing age, the skin and its appendages undergo marked changes. Alterations include in creased roughness, wrinkling, loss of elasticity, mottling, and a general transparency or thinness. In addition, a wide variety of proliferative lesions appear, giving rise to our general perception of an aged individual. These visible changes are noted primarily in exposed skin and represcnt age-related extrinsic effects, rather than intrinsic age related alterations. Because of the dramatic effects that cumulative insults from physical, chemical, and mechanical trauma have on skin, most research in cutaneous gerontology has focused on elucidating environmental changes. Alterations due to intrinsic aging have received less attention. It could be argued that because skin interfaces directly with the environment, all changes are extrinsic. However, by investigating areas that are more protected from environmental insults, certain inferences about the intrinsic aging process can be made. We have chosen the upper inner arm as an area that might closely resemble intrinsically aged skin. This region is relatively shielded from photoaging by its anatomical location, and is further protected by clothing. It does not receive cxcessive chemical insults and does not undergo deformations and reformations induced by pressure, as does skin on the but tocks.
doi:10.1038/jid.1987.9 fatcat:7i7sjgitp5ev7i7nemzu23xvze