The overall appearance of the skin changes during the course of our lifetime as we age. These changes are determined by genetic factors and the action of damaging environmental factors including, UV light pollutants, and cigarette smoke.
Aging skin is characterized by wrinkles, dryness, loss of elasticity, atrophy and pigment abnormalities. Hair becomes thinner and loses its pigmentation. There's a reduction in the activity of the sebaceous glands and sweat glands, leading to dryness of the skin accompanied by itching.
The total or “cumulative” sun exposure is the single largest factor involved in our perception of aging skin. Not only does the UV damage lead to “photoaging” and unwanted aesthetic effects, it also contributes to the development of pre-skin cancers, and basal cell carcinoma, squamous cell carcinoma and melanoma.
Photoaging (also known as "dermatoheliosis”) is a term used for the characteristic changes to skin induced by chronic ultraviolet radiation. Photoaging is attributed to the total (cumulative) UV exposure throughout one’s life. Photoaged skin is wrinkled and associated with discolorations such as freckles, precancerous lesions and dilated blood vessels (telangiectasias). There is extensive loss of collagen and elastin histologically. Those most susceptible are blue-eyed, fair-complexioned persons.
Loss of subcutaneous fat leads to a loss of fullness and roundness of the facial contours of youth. This results in a sunken in appearance of facial structures. There is a loss of elasticity of the tissue which leads to sagging under the effects of gravity.
Loss of elasticity and gravity effects results in sagging of the neck area.
Pigmentation abnormalities and "sun spots" or lentigos appear.
Muscles of facial expression insert directly under the skin and thus years of facial expressions like wrinkling of the forehead leads to a constant folding of the skin, producing so-called “hyperdynamic wrinkles”. These wrinkles initially appear only with facial movement but over time they remain as wrinkles at rest.
The picture below is that of a delivery truck driver for 28 years. Ultraviolet A (UVA) rays transmit through window glass, penetrating the epidermis and upper layers of dermis. Chronic UVA exposure can result in thickening of the epidermis and stratum corneum, as well as destruction of elastic fibers. Note the accelerated photo-aging on the side of increased sun exposure.
Seborrheic keratoses(seb-o-REE-ik ker-uh-TOE-sEEs) are very common benign lesions found on middle-aged and elderly people. These lesions are sometimes called, “age spots”, but I like to refer to them as “wisdom spots”. They are not very common on people younger than 30 years of age, but once they develop, new lesions will appear throughout one’s life. I sometimes joke with my patients that they will collect them with each new birthday. And yes, anyone lucky enough to live a long life will get them; it’s part of life. It’s part of the normal aging process of the skin.
Actinic keratosis (plural, actinic keratoses) is considered to be a premalignant skin lesion that occur on chronically sun-exposed areas such as the face, neck, upper chest, forearms and hands. They are often found on the scalp of bald, fair-skinned men with a history of chronic sun exposure. They appear as reddish, slightly scaly lesions.