Growth And Changes In Color
The exposed skin is thinner in older people than in younger people. Occasionally coarse comedones (blackheads) are present. Discrete white, firm lesions may appear on the forehead and cheeks. These are harmless milia made up of keratin, the horny, fibrous protein of the outermost layer of the skin.
Though the color of the face is generally more pallid with age, the overall appearance varies due to blood vessel changes and pigmentary abnormalities. A mottled, blotchy redness is due to dilatation of small surface vessels (telangiectasia). Sometimes the vessels are individually quite prominent. At other times, the surface capillaries may have leaked due to solar deterioration of the supporting tissue. This produces livid blotches termed ecchymoses which may be present for a long time before resorption occurs.
Coarse yellow markings may be present on the forehead and sometimes on the cheeks. The skin surface seems to be filled with rectangular patches of varying size between the folds. This elastotic degeneration is due to thickening and clumping of light-damaged fibrous tissue under the skin surface. It is finer about the lips, where it emphasizes the skin folds.
Although the pigmentary cells are reduced in number as a natural result of aging, irregular pigmentation appears on the light-exposed areas. This may be simple freckling (lentigines) seen particularly on fair or gingery skins. Larger patches of melanin pigmentation 0.5 to 1.5 centimeters in diameter, are common. These are known colloquially as ‘‘sunspots,’’ ‘‘liver spots,’’ or ‘‘age spots.’’ Raindrop-size nonpigmented white areas appear on the outer arms and legs. Long forgotten scars are also revealed due to loss of obscuring pigment.
Apart from causing cosmetic concern in some, none of these changes is harmful in nature. However, irregular horny lesions can present. They are termed actinic keratoses. They may be flat and scaly on the ear tips or lips, or thicker and more craggy on the cheeks or sides of the neck. It is debatable whether they ever become malignant, but they can be a mechanical or cosmetic nuisance and do occur in skin more prone to malignant change.
Various other warty excrescences are found in the aging skin. They can be common warts, which are often present singly in unusual places and are of unusual form.
Seborrheic warts (keratoses) are more common. They are waxy, brown lesions varying in size from a few millimeters to two to three centimeters in diameter. There may be one or two lesions on the face. However, on the back the number may be much greater, and they tend to lie along the skin folds. They are harmless, but may be a cosmetic or mechanical nuisance.
The Hutchinson’s freckle (now termed lentigo maligna) is a rare growth most commonly present on the face. It is an irregular, flat brown patch one to three centimeters in diameter. It is seen in those who have had much sun exposure throughout their lives, as witnessed by their weathered faces. Though it usually remains quiescent, it may ultimately develop into malignant melanoma.
Medicine EncyclopediaAging Healthy - Part 4Skin - Intrinsic Changes, Extrinsic Changes, Growth And Changes In Color, Skin Cancer, Conditions Of The Normal Aging Skin