University of Southern California Mrs. T.H. Chan Division of Occupational Science and Occupational Therapy
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Aging Skin

For everyone, changes come in our physical well-being as we get older. Even though people are able to remain healthier throughout their lives because of efforts that can be made to eat better, exercise, and avoid damaging habits (like smoking or abuse of drugs or alcohol), the fact remains that our bodies just cannot be the exact same at age 40, or 50, or 60, as at age 20. This truth applies to skin as well: Aging skin is more vulnerable to pressure ulcers (which means the same thing as "pressure sores" or "bedsores") 1, as some of our participants, including Dave and Helen, noticed.

Although it may seem like just a simple covering for the body, healthy skin in fact is considered an organ, with important work to perform, including:

  • Helping to protect muscles, blood vessels and other internal workings from injury
  • Blocking out bacteria that could cause infections
  • Preventing dehydration, or too much loss of fluids
  • Keeping body temperature maintained (for example, by sweating, which cools us)
  • Feeling a variety of sensations through sensors located in the skin, including pressure that is light, heavy, sharp or dull; heat or cold; and the sense of touch (such as being able to identify what an object "feels like")

When people with spinal cord injuries have reduced or missing sensation below the level of the injury, it is not because of damage to the skin or to the sensors in it. It is because the "messages" the sensors send along nerves to the spine no longer get transmitted all the way to the brain; instead, the sensation messages get stopped where the spinal cord is damaged.

Skin has a number of layers, divided into two main types: the epidermis, or outer layers of skin that have no nerve endings or blood supply in them; and the dermis, or the living layer of skin where blood flows through capillaries, or tiny blood vessels, and where nerves and sensors are found. One of the ways that doctors identify the difference between stages of pressure ulcers is by whether the epidermis and dermis are both affected, and how badly each is damaged by the ulcer. Hair roots, sweat glands and sebaceous, or oil, glands are also located in the dermis.

The very top layer of the epidermis (which is what most people are referring to when they say "skin") gradually sheds, flaking off in tiny bits all the time. We usually don't notice this because the next layer of epidermis is now on top and becomes our "skin." The tissue in the dermis will eventually mature, turn into epidermis and come to the surface as the outer layer of skin. This process is called epidermal turnover. As we get older, the speed of epidermal turnover slows down by as much as half. It is thought that this happens because special cells called fibroblasts, or building blocks of skin fibers, decrease in number 2. Fewer fibroblasts also means slower recovery from wounds, which could have contributed to the problems Alley had when, at age 76, she got a pressure ulcer that just would not heal using her usual methods.

Aging skin also contains less collagen 1, a skin fiber that helps skin keep a smooth, "plump" look. (This is why beauty treatments often claim to increase collagen.) Both the epidermis and dermis become thinner with age. With less collagen and thinner layers beneath, older skin becomes more dry, wrinkled, and loose, and provides less "padding," especially over bony prominences, those areas where bones are nearest the surface (namely, the hips, tailbone, back of the head, shoulders, elbows, inner knees, and heels). So, what's the result of all this? Forces of friction (rubbing), shearing (sliding or scraping) and pressure are much more likely to cause blistering and pressure ulcers in aging skin 3. This might help explain why our study participant Mitch, who went 34 years with only one pressure ulcer, suddenly got four ulcers in just two years.

Another complication of older skin is that the tissue beneath loses some of its flexibility, due in part to changed performance of a skin component called elastin 1. This, in turn, gives less even distribution of weight, so that a lot of pressure is concentrated on just a small area. And more pressure, whether it comes from being overweight or from aging skin, can lead to a pressure ulcer.

Previous injuries or medical treatments to the skin can also set the stage for new pressure ulcers. People who have had surgeries to repair previous pressure ulcers often report that new pressure ulcers arise on the scar of that old surgery; our study participants Helen, Ken and Tom all found themselves in this situation.

If this sounds like there's nothing you can do about aging skin - after all, you can't help getting older! - the good news is that there are steps you can take to help make up for the changes in your skin. These measures include moisturizing your skin regularly; making sure you are getting good nutrition, with plenty of protein in your diet; drinking plenty of fluids, especially water; taking extra care to avoid injury, friction and shearing; taking extra care to do regular pressure reliefs; and doing one or two thorough skin checks daily. And once you are aware that pressure ulcers often develop on old scars, you can pay special attention to any scars you might have when you do your skin check. Your physician, health care provider or care attendant might have more tips for you that are suited to your particular needs and lifestyle. Remember that aging skin may be different, but, when you treat your skin right, it can still do a good job of helping to keep you healthy!

If you want to read more about how aging skin affects people with spinal cord injuries, a good site is provided by the University of Washington, which operates clinics specializing in treatment of people with spinal cord injuries; Maintaining Healthy Skin is a page of information about skin, which includes an illustration of the layers of skin. Spinal Cord Injury and Aging, an article intended for health care professionals and consumers alike that talks about changes throughout the body as a person with a spinal cord injury ages, can be found on eMedicine.com, a privately-operated website that puts high-quality articles on medical topics available to the public without needing to subscribe or pay fees. Another article, Aging With A Disability: What's It Like?, which has interviews with a number of people who are aging with disabilities, is on the website for New Mobility magazine.

1 Consortium for Spinal Cord Medicine. (2000). Pressure ulcer prevention and treatment following spinal cord injury: A clinical practice guideline for health-care professionals. Washington, DC: Paralyzed Veterans of America.

2 Kramer, J. D., & Kearney, M. (2000). Patient, wound, and treatment characteristics associated with healing in pressure ulcers. Advances in Skin & Wound Care, 13, 17-24.

3 Witkowski, J. A., & Parish, L. C. (2000). The decubitus ulcer: Skin failure and destructive behavior. International Journal of Dermatology, 39, (12), 894-896.