Aging of the Skin
Wrinkles , Gray Hair

Dr.Nabil AL WATTAR
Dr.watar@scs-net.org

Definition : Aging of the skin is associated with loss of Youthful appearance, it is characterized by decreased skin tautness and the development of wrinckles.
Of greatest concern are those changes which occur on the exposed parts of the body . The hair may become thiner or turn gray. There may be prominent tiny blood vessels ( telangiectasiase and hemangiomas), pigmented lesions ( letigines), and hyperkeratotic growths ( solar and seborrheic keratoses ), as well as other tiny excrescences ( papillomas) appearing on the cutaneous surface.



These alteration may begin as early as the third decade of life, and are most pronounced in the areas of greatest sun exposure. The major hereditary factor contributing to the susceptibility of sun-induced physical changes is the innate skin pigmentation. 
Rarely, precocious aging is seen in conjunction with an underlying systemic illness such as progeria, xeroderma pigmentosum, dyskeratosis congenita, diabetes mellitus, and Werner, Bloom and Down's syndromes.
The single most significant external factor associated with cutaneous aging is the amount of solar radiation received by the individual during his lifetime. Endogenous protection afforded by the degree of melanization of the skin is a major determinant in the ravage of suninduced changes. Numerous researchers have demonstrated by means of histopathologic examination of skin biopsy specimens from exposed and nonexposedskin from various skin complexion types that the degree of induced damage is directly proportional to the inherent pigmentation. Of those changes seen in Caucasian skin types, the difference is in degree of damage, whereas darkly pigmented people exhibit minimal changes.
Aged skin is generally pale, dull, wrinkled, somewhat dry, rough and flaking. Hair thins, becomes rough, fades, and grows more slowly owing to a slower anagen phase . The androgen-dependent underarm and pubic hair becomes scarcer and may disappear. Sebaceous, aprocrine, and eccrine sweat gland activity diminishes. Invisible deterioration of the homeostatic skin functions-barrier function , thermoregulation, vitamine D production, immunocompetence-occur at the same time .
Alterations in photoexposed skin are proportional to the amount of sun radiation received. Mild modifications may be manifest by dry and atrophic skin, numerous wrinkles, occasional telangiectases, and yellow-brown pigmented patches ( senile lentigines). The skin of subjects who have spent long periods of their lives exposed to the sun's rays have burnt, orangy-tan, rough skin that lacks elasticity, is deeply furrowed, and scattered with fine telangiectases, senile lentigines, and keratotic lesions (solar keratoses ). Basal cell cancers and squamous cell cancers are frequently encountered. Striking histologic changes are thickening of the stratum corneum, atrophy of the epidermis, considerable flattening of the dermoepidermal junction, and degeneration of collagen bundles, which are often transformed into extensive basophilic amorphic masses ( senile elastosis ) . a decrease in elastin and ground substance biochemically characterize the sun-induced dermal alterations.
Skin pigmentation is the first line of natural defense against long-term actinic damage. Consequently , the clinical and histopathologic differences between sun-exposed and covered black skin are generally less pronounced and appear later. Furthermore, in relationship to age, senile elastosis and skin pigmentation have been shown to be closely related. Severe senile elastosis is consistently seen in 60-year-old people with phototype I-III white skin ( light complexion) exposed to the sun, whereas only 50% of those with phototype IV-VI skin ( dark complexion ) 
display a similar degree of alterations.

Laboratory Tests
The diagnosis of aging skin is made on clinical grounds; however, certain lesions may require additional testing ( fungal scraping or biopsy) to confirm clinical suspicion or exclude malignancy ( basal or squamous cell carcinomas, melanoma, etc.).

Management 
Aging is a natural and inexorable process. Nevertheless, the onset and development of clinical alteration of the skin can be delayed by certain prophylactic measures. Modern pharmacology and cosmetology offer many means for improving the look of aging skin.
Skin should be protected from damaging ultraviolet rays from an early age . Excessive exposure to sun should always be avoided, and the skin should be protected with an appropriate sunblock or screen. Most sunscreen products contain para-aminobenzoic acid (PABA) and its esters, benzophenones, cinnamates, or salicylates. In addition, many of the vegetable oils used as vehicles ( olive, coconut, cottonseed, and sesame oil ) also absorb part of solar irradiations. These cosmetics are usually pleasant to use and cause sporadic side-effects ( contact dermatitis ) . However , such filters mainly absorb the ultraviolet B rays while letting through the ultraviolet A rays, which are prevalently responsible for the long-term degradation of the skin. Sunblock creams contain opaque substances, such as zinc oxide, titanium oxide, bentonite, and taolin, that reflect or absorb most of the solar spectrum. These compounds are not cosmetically pleasant and allow only minimal sun-tanning. Anti-sunray preparations do not always give sufficient protection from actinic damage. In these cases oral administration of systemic photoprotective substances, such as betacarotene and canthaxanthin, is indicated. Furthermore ingestion of these carotenoids causes the skin to assume a bronze color not unlike a real suntan.
Prevention of skin aging should be based not only on photoprotection but also on accurate skin hygiene. The market offers a vast range of detergents. Moisturizers, nutrients, and cosmetics, usually specific for a certain type of the skin. The active ingredients of the majority of the aging -preventing products ( e.g., vitamins A and E, phospholipids, and carotenoids ) are photoprotective and/or have the capacity to reduce the formation of free radicals and to improve some of the enzymatic pathways of normal cell activity.
Cosmetic emulsion, mask, and gels for improving the clinical aspect of aged skin are equally plentiful. Part of the antiwrinkle products take advantage of high hydrate substances that increase the moisture in the stratum corneum, thereby making wrinkles less noticeable.
Women require no special advice about sun protection, however, our culture has unfortunately imposed the "liability" of loss of youthful appearance most heavily upon this group. There seems to be no end to the number of creams, lotions, and masks appearing on the market which promise to restore or prevent aging of the skin. Moisturizers of both types ( oil-in-water or water-in-oil emulsions) temporarily increase the water content of the stratum corneum, which may make finer wrinkles seem less obvious; however, they can offer nothing more. The less oily or the water-based products are most suitable for the acne-prone individual. It has been noted that the darker individual's eyes, hair, and skin color, the greater the chance of developing acne from topical products. ( the less moisturizer used, the less acne .) No topical agent can restore changes occuring deep within the skin ; therefore, topical collagen's sole efficacy, if any, leis in the ability of its vehicle to hydrate the skin . furthermore, over-the-counter hormonal creams are of no benefit and may be harmful if used excessively because of the possibility of systemic absorption of the active ingredient. The potential of serious systemic side-effects is a reality with the application of these topical preparations.
The value of cosmetics in the treatment ofaging skin should not be overlooked. Skillful camouflage of skin alterations with common beauty products can rapidly improve one's appearance.
A variety of cosmetic surgical approaches to the correction of aging skin defects have been developed, including hair tranplantation , face lifts, blepharoplasty, and rhinoplasty. Injectable materials available to modify wrinkles or depressed scars include silicone, collagen, polylactic acid, hyaluronic acid ,Botulinum toxin (Botox )* and newer material which is mixed with the patient's plasma and injected as a matrix for the formation of new collagen. Collagen implantation has proved to be most helpful.
This treatment affords good correction of depressed scars and nasolabial fold wrinkles, frown line, glabellar lines and other line when used by experienced practitioners.