Aging Skin

AGING – FACTS AND REMEDIES CONCERNED

Aging can be assessed by wrinkles, surface irregularities, skin laxity, etc.

It can be divided into intrinsic and extrinsic aging.

Intrinsic aging

Intrinsic aging refers to the natural process of chronologic aging.

Intrinsic aging affects both sun-exposed and non-sun-exposed skin and is characterized by dryness, laxity, skin atrophy, and fine wrinkles.

Histologically, one may see a thin epidermis with an intact stratum corneum, resulting in prominence of vasculature leading to transparency of the skin. Others are flattening of dermoepidermal junction, a decrease in dermal thickness, diminished dermal vascularity, and a decreased ability of dermal fibroblasts to produce collagen, manifested as increased time for wound healing.

Intrinsic aging is genetically mediated predominantly. Other factors which contributed may be the natural effects of gravity, expression lines, sleep lines, and hormonal changes.

Extrinsic aging

It is mainly due to environmental factors including smoking, wind, chemical exposure, and the most important one is ultraviolet (UV) radiation which is of two types UV-A and UV-B. UV-B is considered to be the most damaging causing sun burn, erythema, DNA damage, and ultimately skin cancer. UV-A, on the other hand may cause much chronic photodamage to the skin but at higher levels. Extrinsic aging is characterized clinically by fine and coarse wrinkles, dryness, laxity, roughness, pigmentary changes, and telangiectasias.

Histologically, photodamage can cause an increase or a decrease in epidermal thickness corresponding to areas of irregular contour and atypia of keratinocytes corresponding to rough solar keratoses. UV light causes degeneration of collagen and deposition of altered elastic tissue predominant as wrinkles and yellow discoloration of skin in the dermis and on microcirculation is manifested in telangiectasias.

Mechanisms

In 1954 free radical theory of aging was a proposed postulate that aging is a result of reactions caused by free radicals. Both chronologic aging and photoaging are associated with production of excessive amounts of free radicals, which contain one or more unpaired electrons. When left unchecked, these can damage cell membranes, proteins, and DNA. The senescence of cells may also be linked to mutation in the mitochondrial DNA. It has been demonstrated there is a causal relationship between telomere shortening and in vitro cellular senescence.

Collagen breakdown which is due to induction of metalloproteinases mediates the damaging effect of UV exposure. This pathway can be inhibited with pretreatment by retinoids .Photodamaged skin leads to reduction in precursors of both collagen1 and 3 types. Solar elastosis, a blue colored staining material which histologically mimics elastin is seen in severely photodamaged skin.

REMEDIES

NON-ABLATIVE

These procedures have replaced traditional laser resurfacing and invasive surgical procedure due to it being a less invasive procedure and decrease recovery time.

LASER

It is based on concept that various light devices can induce collagen remodeling and thermal damage to the dermis without affecting  the epidermis.

Targets mainly used in laser are water, hemoglobin and melanin.

Collagen and elastin fibre is mainly due to edema of endothelial cells and connective tissue, recruitment of inflammatory cells, which release cytokines and other growth factors leading to collagen remodeling. Formation of collagen in dermis is histologically confirmed following the laser treatment. Collagen remodeling continues for a period of 6-12 months.

Nonablative photo rejuvenation(improvement in sun damage and aging skin) uses two main targets, discrete chromophores(oxyhemoglobin and melanin) in the dermis(intense pulse light laser IPL) or the dermo-epidermal junction and mid infra red wave lengths to target tissue water(neodymium:yttrium-aluminium-garnet ND:YAG). Deep penetration and scattering of light is achieved with relative long wave length, mild water absorption and poor oxyhemoglobin and melanin absorption. Results are gradual and progressive and multiple treatment sessions are required with both approaches.

IPL LASER

It targets both melanin and oxyhemoglobin chromophores using a spectrum from 560-1200nm. It is indicated in conditions like unwanted hairs, pigmentation, vascular birth marks, lentigines, rosacea induced erythema. IPL leads to dermal remodeling with histologically new collagen formation six months after the last treatment.

Nd:YAG LASER

It is minimally absorbed by melanin, deeper penetrating, used longer wavelength and causes less damage to epidermis. This laser target dermal collagen and pretreatment with topical anaesthetic cream is required due to the moderate pain associated with its use.

OTHERS

1450nm Diode laser targets collagen and stimulates fibrosis in the upper dermis with improvement in perioral and periorbital wrinkles.

1540nm Er:Glass laser is also used in periorbital and perioral wrinkles. There is an increase in thickness in dermis by 17%.

Fractional photothermolysis (reliant lasers) is a new technology and new treatment protocol that targets only a small fraction of skin surface like the pixel in a digital photograph and treats photo damaged skin. It is mainly used in dyschromias including melasma, acne and other scars, and photo-damaged skin of chest, face, neck and hands.

  TOPICAL COSMECEUTICALS

It includes retinols and Retinoids, Alpha hydroxyl acids, F-creagel, Vit C and Growth factors.

Retinol and Retinoids

A common ingredient found in antiaging creams.Retinol represents the main dietary source transport and storage form of vit A .Retinoids consists vit A and belongs to a family of structurally and functionally related compounds.It is (vit A) obtained through dietary meat and cannot be synthesized in body.It is converted in body to its biological active form all trans-retinoic acid(tretinoin) through an intermediate product retinaldehyde.Tretinoin is 24 times more effective than retinol and the cutaneous concentration of tretinoin is 1000 fold less with topically applied retinoid than with tretinoin. Interaction with specific nuclear receptors is controlled at the cellular level by trans-retinoic acid.UV radiation causes significant reduction in collagen formation due to upregulation of metalloproteinases such as collagenases and gellatinases, decrease in precollagen synthesis and due to intrinsic aging process.Pretreatment with tretinoin reduces all these. Tretinoin use leads to both clinical and histological improvement of photodamaged skin. Use of tretinoin shows a dose dependent improvement in fine wrinkling, mottled pigmentation and laxity.

Increase in epidermal thickness (granular layer), compaction of stratum corneum, increase in epidermal and dermal mucin, decrease in melanin content, improvement in the structure of the dermo-epidermal junction and improvement in keratinocytes ultra structure has been noted histologically. Tazarotene (newer topical retinoids) is also as effective as tretinoin in reducing moderate pigmentation and fine winkling of photoaging skin.

VITAMIN C

This is a new product popular in the anti aging cosmoceutical fields.

It is absorbed percutaneously and chemically composed of isomers L and D- ascorbic acid. Synthesis of collagen triple helix is due to its action, acting as a co-factor for hydroxylating enzymes. It also stimulates pre collagen synthesis. It mainly has an antioxidant activity and quenches free radicals. It also reduces UV light exposed skin wrinkling. It enhances the photo-protective effects of sunscreen. It first line of defense against oxidative damage due to water solubility. It also replenishes Vit E (a lipophilic antioxidant). Due to its biochemical effective reducing properties, can act as a free radical scavenger in human tissue.

ALPHA HYDROXY ACIDS

Has been used for years as exfoliants, emollients and moisturizers and belongs to a group of hydrophillc organic acids.

They cause smooth appearance of skin as a result of their keratolytic activity, resulting in reduces adhesion of keratinocytes and increased turnover of stratum corneum.

They include glycolic, lactic, citric, pyruvic, malic and tartaric acid.

Use of these agents for antiaging purpose has been a boom recently. Lactic and Glycolic acid are commonly used.

They increased epidermal thickness; glycosaminoglycans increase epidermal skin firmness as measured by ultrasonography without any accompanying dermal change.

Increased acid mucopolysaccharides, improved quality of elastic fibers and increased density of collagen were also noted Histologically.

GROWTH FACTORS

Cytokines or growth factors are the latest development in the treatment of aging skin.

According to some studies TGF-beta can increase collagen synthesis, promote granulation tissue formation, increase the size of regenerated dermis, and stabilize the dermoepidermal junction. There is an improvement in skin texture ,wrinkle depth and texture as measured by optical profilometry. Increase in epidermal thickness and grenz collagen was demonstrated histologically.

COMBINED USE OF COSMECEUTICALS AND NON ABLATIVE LASER THERAPY.

There has been no controlled study which shows the enhanced result when laser and cosmaceuticals are combined together which on the contrary should have been theoretically.

In general, when using those agents that each have a mild to modest efficacy, expectations need to be realistic.

SURGICAL OR ABLATIVE PROCEDURES

Surgically we revert age up to 20-30 years with the use of rhydiectomy, hair transplantation, chin lifting, neck lifting, breast lifting, tummy tuck, buttock lift, vaginoplasty etc.

Anti-Wrinkle peel is the best tool to defy signs of ageing.However, it is our impression that far greater success is achieved by the use of a program that not only combines multiple cosmeceutical agents but also takes advantage of the distinct benefits of the nonablative lasers and ablative procedures.