Extrinsic aging

Extrinsic aging is generally caused by external factors introduced to the body, such as smoking, excessive alcohol consumption, poor nutrition, pollution, harsh weather and chronic sun exposure (photoaging). Other factors include repetitive facial expressions, gravity and sleeping positions. Of all these external factors, sun exposure is considered to be by far the most significantly harmful to the skin and according to Baumann (2007) 80% of facial aging is believed to be due to chronic sun exposure.

1. Sun exposure (Photoaging)
The human skin is exposed to UV and infrared radiation practically everyday and without protection from the sun’s rays, a few minutes of exposure each day over the years can cause noticeable changes to the skin as the skin loses the ability to repair itself and as such, the damage accumulates. The clinical manifestation of photoaging depends on skin type, skin colour and the history of long-term or intense sun exposure. An individual with fair skin with a history of sun exposure will develop more signs of photoaging than a dark skinned individual. For individuals with the darkest of skins, the signs of photoaging are often limited to fine wrinkles and complexion marked with spots or blotches of different shades or colours. It has been shown that repeated ultraviolet exposure damages the skin by breaking down collagen, impairing the synthesis of new collagen and attacking elastin, thereby causing immense damage. Photoaging is characterised by coarse, deep, severe wrinkling as well as pigmentary changes on exposed areas such as the face, neck and forearm. Losses in skin tone and elasticity, increased skin fragility, and benign lesions are also observed in skin affected by photoaging.

2. Cigarette smoking
Cigarette smoking is the second causative factor of premature skin aging after photoaging as it triggers biochemical changes in the body, which accelerate the aging process. It has been shown that individuals who smoke 10 or more cigarettes a day for a minimum of 10 years are statistically more likely to develop deep wrinkled, leathery skin than non smokers. Smoking exerts a noticeable effect on the skin such that it is often possible to detect whether an individual is a smoker or not by simply looking at his or her face. Such individuals have more wrinkles and their skin tends to have a greyish pallor compared with non smokers. The most serious damage to the skin through smoking is often caused by the following:
a. reduction in the body’s storage of vitamin A, which produces protection from skin damage
b. continual puckering from drawing on a cigarette as well as squinting in reaction to cigarette smoke create deeply wrinkled skin around the eyes and mouth – these are classic signs of “smoker’s face”
c. restricted blood flow through the capillaries thereby preventing oxygen and nutrients getting to the skin
d. restriction of the absorption of vitamin C, which is a vital oxidant for skin protection and health
e. acceleration of the decrease in collagen production, an enzyme vital to the skin’s elasticity.

3. Facial Expression/ Facial Animation
Each time facial expressions are made, a facial muscle or facial muscles are used. These cause a groove to form beneath the surface of the skin causing it to form lines with each facial expression. As the skin ages and loses its elasticity, it loses its ability to spring back to its “line-free” state and consequently grooves become permanently etched on the face as fine lines and wrinkles (referred to as expressive wrinkles).

4. Sleeping positions
Continually sleeping by resting the face on a pillow in the same way every night for years on end can lead to the development of wrinkles on the face. These wrinkles (also known as sleep lines) eventually become etched on the surface of the skin and no longer disappear when the head is not resting on the pillow.

5. Gravity
Naturally, gravity pulls on our bodies; however, the changes related to gravity become more pronounced with age. When the skin loses its elasticity, the effects of gravity become more evident causing drooping of the eyelids and eyebrows, elongation of the ear lobes, formation of jowls and “double chin”, drooping of the tip of the nose, and disappearing of the upper lip whilst the lower lip becomes more pronounced