Ageing Skin
Dr Bill Revell

AGEING

Process of progressive generalised
impairment of function

Resulting in an increasing age- specific
death rate

Tom Kirkwood
Ageing

Results from accumulation of un-repaired
damage of somatic cells and tissues

Progressive failure of maintenance
mechanisms to respond to environmental
attrition

Free radical damage may offer a unifying
theory for cellular senescence, underlying
human ageing and age related diseases
Deteriorating Tissue Function

Associated with change in cell
functioning

+/- Change in cell turnover when old or
defective cells are not replaced
age related changes in metabolic
functions

Reduced oxidative phosphorylation by mitochondria

Diminished synthesis of structural, enzymatic and
regulatory proteins

Decreased capacity for uptake of nutrients

Increased DNA damage and diminished repair of
chromosomal damage

Accumulation of oxidative damage in proteins and
lipids (eg lipofuscin pigment)

Accumulation of advanced glycosylation end
products
Morphological alterations

Irregular and abnormally lobed nuclei

Swollen, pleomorphic and vacuolated
mitochondria

Decreased endoplasmic reticulum

Distorted Golgi apparatus
Ageing skin; a preamble……….

Huge efforts to hide and disguise

Gerontological discussion has
little to do with morbidity or
mortality; very few patients die of
old skin, or succumb to skin
failure

Importance is primarily
psychological

Emotional impact of skin ageing
should not be underestimated
Ageing skin

Wrinkled

Most pronounced on sun
exposed parts

Age or liver spots

Loss of hair

Sagging facial muscles

Increased fragility

Skin contains less collagen
and elastin; abnormal
changes to collagen and elastin

Thinner; less elastin; less collagen

Abnormal elastin and collagen

Wrinkling; most pronounced on sunexposed skin
Collagen Cross Links

Eg intermolecular cross links between lysine
residues in adjacent collagen helices

Non-reducible cross links increase with age

Arise as a side effect of free radical damage
Advanced Glycosylation End Products

Post-translational modification of
collagen by sugar (AGE products)

Non-enzymatic attachment of glucose
to proteins

Formation of irreversible cross links
Structural age changes in skin
dermis
Age related changes – “normal” ageing
Epidermis



Epidermis thinner

Increased “scaling off”

Declining rate of cell division
Decrease in dermal papillae

Decrease in “interdigitation”

epidermis held less tightly

Looser feel of ageing skin
By age 80yr keratinocyte turnover in epidermis slows to 50%
Age related changes – “normal” ageing
Dermis

Reduction in fibroblast numbers

Less matrix turnover

Dermis thins more than epidermis (transparency)

Collagenous fibres become larger and coarser


Fat, water, matrix content diminishes
Elastic fibres less resilient

Formation of cross links; some calcification

Skin less able to “smooth out”

Wrinkles

Loss of smooth padding provided by fat cells of the
hypodermis
Age related changes – “normal” ageing
Dermis

Reduction in sweat glands and sebaceous glands




Gradual atrophy
Sweat less; drier and scaly skin

Reduced ability to regulate body temperature

Heat exhaustion more likely
Generalised reduction of blood flow to skin

Skin surface cooler; slow growth of hair and nails

Nails yellowish, ridged, thicker with Ca2+ deposits
Decrease in hair follicles, loss of body hair

cf (males) eyebrow, nostril, ear hair becomes coarse and grow more
rapidly

Reduced hair pigment – grey/white is default colour
Age related changes – “normal” ageing
Hypodermis

Layer of loose connective tissue, containing fat

Subcutaneous tissue; not part of skin (technically)

…. but changes affect skin….

Generalised loss of fat; most obvious in face and limbs

Major cause of wrinkles

“old age is when, upon getting out of the bath, you notice the full
length mirror is steamed up – and you are glad of it” (Modern
Maturity)
Age related changes – “normal” ageing
Hypodermis

Loss of subcutaneous fat also loss of padding

Combine with reduction of blood supply to skin

Bed sores in areas of constant pressure over bony
prominences

Loss of fat

Diminished insulation; allows heat to escape

Need to keep rooms warmer than young people can tolerate
“Age” or “liver spots”

Intrinsic – resulting from the
ageing process

Resulting from UV damage:
photo-ageing

dermatoheliosis

Free radical damage

Lipofuscin deposition in cells,
often in secretary cells of
sweat glands

End product of lipid
peroxidation
Senile
FRECKLES
involving
melanocytes

pigmented area (melanin)
surrounded by normal-appearing
skin.

melanocytes are present; may be
increased in number

may evolve slowly over years, or
may be eruptive and appear
suddenly

Pigmentation may be
homogeneous or variegated, with
a colour ranging from brown to
black.
cf solar LENTIGO
Age related dysfunctions

Senile angiomas

75% >70yr

Elevated clusters of dilated
capillaries

Seborrheic keratosis

Benign epidermal tumours

Greasy wart-like crust often
forms on surface of tumours

Senile pruritis (itching)

Loss of oil secreting sebaceous
gland

Dry, less pliant skin; cracks

Deep fissures that exude tissue
fluid
Herpes Zoster
(shingles)
Viral disease
Peak incidence 50-70yrs
Varicella (chicken pox) when young
Remains dormant in nervous system
When reactivated, attacks sensory
nerve fibres and skin supplied by
nerves
Itching, red papules, fluid filled
vesicles, dries down and forms crust,
scales off, leaving pigmented area
1 – 2 weeks, pain for months
Skin Cancers
cancers of all types increase with age

Melanoma – most serious

Associated with sun UV light

Develops in pigment cells
(melanocytes) of a preexisting epidermal mole
Non-melanoma skin cancers >50%
pink, red or white

Basal cell carcinoma
 Most common
 Develops from cells in basal layer of epidermis
 Most common in regions with strong sunlight
 Most prevalent in light skinned races
 Head and neck usually
 Rarely metastasise
 Variously reddish patches; small open sores;
bumps
 Growths can invade underlying tissue
Non-melanoma skin cancers

Squamous cell carcinoma






Less common
Associated with excessive sun exposure
More common in elderly, esp. older men
Appears as a wart
Often in form of hard nodule, with small
reddened areas showing through surface
May be ulcerous