skin

Skin

Introduction

Wrinkles are a commonly used marker of ageing but they owe more to sun damage than to old age itself. Wrinkles are a cosmetic problem, but photo damage can also lead to life-threatening skin cancers. Sores and ulcers are serious skin problems with a different etiology.

Skin structure

Age-related changes

Compared to a healthy young person:

The outer layer of skin, the epidermis, may gradually thin.
There is loss of integrity between the epidermis and the dermis. This makes ageing skin more susceptible to simple trauma and to shearing forces.
The dermis becomes thinner and less flexible.
The dermis has fewer fibroblasts. This results in a decreased production of:
- Elastin, which gives the skin elasticity.
- Collagen, which gives the skin its strength. which increases the older person’s susceptibility to shearing forces and to wrinkling.
The older person’s skin is dry (xerosis).
Damaged skin is replaced more slowly.
There are fewer specialized immune "surveillance" cells (called Langerhans cells).
The backs of the hands may develop thickened patches (keratotic nodules).
A loss of melanocyte function means that the older person does not tan readily. More seriously, their skin is less well protected from the effects of the sun than the skin of younger people, making skin cancer more likely.
Pigmented areas develop as melanin clumps form e.g. on the face (telangiectasia)
Many old people have bruised hands and arms (senile purpura). This may be because their less elastic skin makes blood vessels in the skin more vulnerable to damage and because the blood vessel walls thicken and become more rigid.

Effects of photo ageing

More elastin than normal in the epidermis. The epidermis thickens, but then atrophies.
Wrinkles.
A more pronounced loss of Langerhans cells.
A more pronounced loss of collagen.
A lifetime’s exposure to sunlight means that the older person is more likely to develop skin cancer.

Pruritus

Itching (pruritus) may occur in up to 2/3 of older people. It is most likely to be the result of dry skin but may have pathological causes including scabies, eczema, blood disorders and liver and kidney disease.

Sores and ulcers

Leg and foot ulcers and bed sores are serious conditions. They compromise the patient’s mobility and are costly and time-consuming to treat.

Pressure sore development. Low pressure for long periods and high pressure
for relatively short periods can both cause sores, but the body may be better able to
cope with short periods of high pressure.

Bed (pressure) sores

When a resting person is unable to move all or part of their body there is no relief of pressure points where their body contacts the bed or chair they are on. Pressure sores may develop – within hours in vulnerable people.

Pressure sores arise because shearing force and downwards pressure caused by the body’s weight squash blood vessels so that tissue is starved of oxygen.

One cause of pressure sores is immobility as a result of an operation (perhaps because of pain, splints or sedation). Pressure sores may even develop on the operating table during long procedures.
The sores can take weeks to heal and may become infected, with fatal consequences.
Hospital staff measure a person’s risk of developing bed sores using an index called the Norton Scale, and move the at-risk patient periodically, to try to prevent sores from developing.
The skin damage is made worse by irritation from moisture and so sores are common in immobile incontinent patients.
Bony parts of the body which are subject to pressure are especially prone to develop sores.
The older person has a reduced nerve supply to the skin, increasing their pain threshold, so that they may take longer than a younger person to realize that they have sores.

Pressure sores - Norton Scale

Score
General physical condition Mental State Activity Mobility Incontinence

4
Good Alert Ambulant Full Not

3
Fair Apathetic Walk with help Slightly limited Occasionally

2
Poor Confused Chair bound Very limited Usually urine

1
Very bad Stupor Bed bound Immobile Doubly

Method of scoring for vulnerability of developing pressure sores.

The 24-hour turning clock

Leg and foot ulcers

The importance of leg ulcers is not due so much to their incidence as to the vast and disproportionate amount of nursing time they use up.

Venous ulcers occur with poor venous blood flow.
Arterial disease may cause painful ulcers which are slow to heal. Diabetics are at risk of developing pressure ulcers on their feet due to arterial and neurological disease. If the causative pressure is not relieved, amputation may become necessary. Good control of blood glucose may be important in preventing such ulcers.

Poor venous blood flow (varicose vein)

Venous ulcers are the most prevalent of hard-to-heal leg ulcers

Hair

With age, melanin is reduced (grey hair) or lost (white hair) from hair follicles.
The age at which hair greys or falls out is genetically determined. Women as well as men lose hair with age.
When hair does not go grey in old age, the person may have hypothyroidism.
Hair becomes more brittle and downy with age (it turns from "terminal" to "vellus" hair), and it grows more slowly.
Older women may notice a conversion from vellus hair to terminal hair on their chins and above their upper lip (the opposite trend to hair on the scalp).
Older men may notice an increase in ear, nostril and eyebrow hair.

Problems of daily living

Ulcers and sores can make a person house-bound either because they have problems moving around or because they need regular visits from medical professionals to dress their skin.

Score	General physical condition	Mental State	Activity	Mobility	Incontinence
4	Good	Alert	Ambulant	Full	Not
3	Fair	Apathetic	Walk with help	Slightly limited	Occasionally
2	Poor	Confused	Chair bound	Very limited	Usually urine
1	Very bad	Stupor	Bed bound	Immobile	Doubly