Physiologic changes in older skin.

Clearly, like all other organ systems, the skin undergoes physiologic decline with advancing age. In the elderly, the stratum corneum may not be as capable of acting as a barrier. Once noxious substances penetrate, they are less likely to be cleared rapidly and often will not provoke any integumental reactions or pain sensations that would serve as warning signals to the aged. Thus older individuals are not only more vulnerable to environmental insults but also fail to recognize that they are being adversely affected. As a result, these substances may accumulate following repeated exposure to the point that the threshold for clinical display is exceeded, whereas the threshold would never be reached in younger individuals. Thus it is not surprising that many of the common problems of the elderly are likely to represent subtle, chronic irritant dermatitis. Then, too, because cellular turnover and repair are much slower, the time to recover from such damaging insults is prolonged. In conclusion, I would like to stress that one of the most important observations to come out of our studies is that there exist cutaneous clues to an individual's physiologic age. It is generally appreciated that some elderly individuals seem to be much more youthful and others much older than their stated ages, suggesting that there may be a wide gap between chronologic and physiologic age. Indeed, one of the central concerns of gerontology is to develop methods by which physiologic aging can be monitored. We are certainly not the first to realize that the skin and its appendages may furnish useful markers of physiologic age.(ABSTRACT TRUNCATED AT 250 WORDS)