Methods of rejuvenating the aging skin are reviewed.
Topical medications with retinoids (tretinoin).
Cosmeceuticals, including examples like alpha and beta hydroxy acids, kinetin and other cytokinins.
Cosmetic skin rejuvenation procedures, including Botulinum toxin, injectable dermal fillers, nonablative light-based procedures, chemical peels, dermabrasion, laser resurfacing and cosmetic surgery.
General rules for preservation of youthful skin appearance are also reviewed.
Skin aging is a complex biological process that is a consequence of both intrinsic or genetically programmed aging that occurs with time, and extrinsic aging caused by environmental factors. The dramatic increase in the aging population and the psychosocial impact of skin aging has created a demand for effective interventions. The advances that have been made in the past 25 years in our understanding of the clinical, biochemical, and molecular changes associated with aging have led to the development of many different approaches to reduce, postpone, and in some cases, repair the untoward effects of intrinsic programmed aging and extrinsic environmental injury.
The topical retinoid, tretinoin (all-trans-retinoic acid), was the first medically approved product for the treatment of photodamaged skin. Now, over a decade of basic and clinical studies document the beneficial clinical and histological effects of retinoids for the treatment of photodamaged and intrinsically aged skin. Clinically, topical retinoids are effective in minimizing fine lines and wrinkles and improving skin texture and mottled hyperpigmentation. Tretinoin decreases fine wrinkles by increasing dermal collagen production via stimulation of synthesis, reducing collagen degradation by inhibiting UV-induced matrix metalloproteinases, and stimulating epidermal turnover, resulting in a thicker epidermis. Clinical changes are dose-dependent, with progressive improvement over a 6- to 12-month period, and slow regression once treatment is discontinued. The greatest obstacle to topical retinoid use is the high incidence of skin irritation, dryness, and the potential for increased photosensitivity. Newtopical retinoids (e.g., tazarotene, adapalene) and novel formulations (e.g., microsponge) available in the last few years have fewer adverse effects and improved tolerance.
Cosmetics and Cosmeceuticals
More than US$ 230 billion is spent annually worldwide on over-the-counter cosmetics and cosmeceuticals to improve the appearance of aging skin. Antiaging cosmetics are touted to erase wrinkles and rejuvenate the skin. Most of these products serve only to camouflage wrinkles and moisturize the skin. Cosmeceuticals, a new category of antiaging products introduced in the 1990s, represent the fastest growing segment of the skin care market. These antiaging products are not classified as prescription drugs or regulated by the Food and Drug Administration, but produce changes in skin structure or function.
- Examples of cosmeceuticals include the alpha and beta hydroxy acids, which are generally found in over-the-counter preparations at relatively low concentrations (3–15%) and may be used to exfoliate the skin, increase cell turnover, and reduce fine wrinkles and mottled hyperpigmentation.
- Kinetin (N6-furfuryladenine) is a cosmeceutical used for the prevention and treatment of skin aging. It is a naturally occurring plant growth factor that retards senescence in plants and has anti-aging effects on human adult skin fibroblasts in vitro. Kinetin appears to be both a direct anti-oxidant and a signaling molecule that stimulates pathways of the maintenance and repair in cells. In a 52-week clinical study in 96 subjects with photodamaged facial skin, twice-daily application of kinetin lessened skin roughness (63%), mottled hyperpigmentation (32%), and fine wrinkles (17%), and also improved skin barrier function as measured by a decrease in transepidermal water loss. Extended treatment with kinetin was well tolerated and did not cause irritation.
- Other cytokinins may also provide benefit for aging prevention, intervention, and therapy. The list of cosmeceuticals continues to grow and claims proliferate. It is important that scientific efforts be devoted to the rational development of anti-aging products and that clinical testing be done to substantiate claims.
Cosmetic Skin Rejuvenation Procedures
Topical agents alone provide some skin-aging prevention and treatment. However, combining use of topical compounds with one or several of the wide array of available cosmetic procedures can help maximize antiaging effects.
- Botulinum toxin, a purified neurotoxin, is one of the most popular procedures for temporary paralysis of select facial muscles and resultant diminution or elimination of unwanted lines in areas such as the glabella, periorbital, and perioral regions.
- A multitude of injectable dermal fillers is available for diminishing skin atrophy and fine and deep rhytides.
- Nonablative light-based procedures can be used to improve fine lines, and possibly skin tone.
- Various skin resurfacing methods, including chemical peels, dermabrasion, and laser resurfacing can been used to improve wrinkles, skin texture, and dyspigmentation.
- Cosmetic surgery produces the greatest improvement in wrinkles and skin laxity, but also has the highest associated risk and longest recovery period. The current trend is to address skin aging before cosmetic surgery is required. This is accomplished by combining available aging prevention and treatment options including daily sun protection and use of topical products, such as retinoids, kinetin, and moisturizers; regular-interval treatments (e.g., botulinum toxin, fillers, and nonablative light-based treatments); and only occasional major surgical procedures, as necessary.
Youthful skin appearance can be preserved to some degree with less-invasive options, mitigating the need for cosmetic surgery. Implementation of skin protection and anti-aging treatment regimens should begin as early as possible and continue throughout life to counteract the effects of intrinsic and extrinsic skin aging. The future in the treatment of skin aging is bright and promises more effective preventive and therapeutic strategies.