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DERMAL
SIGNS OF AGEING SKIN By Gay Wardle
Many modalities including active topicals which target ageing skin are used and delivered widely throughout our industry. These treatments effectively support the delay of the signs depicting an ageing skin however the skin will age regardless. There are several tell-tale signs of an ageing skin. These include the condition of the skin, shrinking bone density, muscle deterioration as well as changes to the fat structure and cellular structures. The skin – our largest organ is constructed of the epidermis, dermis, and hypodermis. All of these layers are abundant with connective tissue – collagen to support and elastin to provide flexibility and strength. The epidermis (the outer layer of the skin) is made of skin cells, pigment, fat, proteins, bacteria, and extra cellular fluid. These are essential for creating a healthy barrier for the lower skin layers. The dermis which is the middle layer of the skin has nerve cells, hair follicles, blood vessels, capillary vessels, sebaceous glands, immune cells, fibroblast cells and ground substance. These all provide nutrients to the epidermis. The hypodermis or subcutaneous layer contains sweat glands, blood vessels, fat, and stem cells. When we are treating an ageing skin, it’s important that we have a thorough understanding of the different skin layers in conjunction with the described tell-tale signs. We also need to consider both intrinsic ageing and extrinsic ageing.
INTRINSIC AGEING:
Intrinsic ageing is the process that takes place over the years regardless of external influences. One percent less collagen is produced in the dermis each year over the age of twenty. As we progress through the years this percentage increases. So, what happens to collagen and elastin fibers as we age? The fibers become thicker and more fiberous and we lose the thickness in the skin that we had when we were younger. As a result of this, the skin loses its firmness and elasticity, and it begins to become more lax. Fine lines and wrinkles are noticeable and continue to develop over time. The skin`s desquamating process declines by 25% to 28% in our late twenties which isn’t really that noticeable until we get to our thirties. In our thirties we begin to lose bone density to the malar bone, this is also known as the zygomatic bone or the cheek bone. Fat cells also begin to shrink in this area and slide downwards. We can also lose lustre to the skin due to changing moisture levels. As the skin enters its fourth decade, collagen production slows down causing a decline in quality. Expression lines become noticeable and as the malar bone decreases, the face shape starts to change. Progressing through to the fifties, hormonal 26
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changes begin to have an impact on skin density. The rete pegs begin to flatten, and the dermis thins. Estrogen, progesterone and testosterone levels change, and the skin can become either dry or oily as a result. During this period, adult acne or rosacea can occur. The barrier function of the skin may become compromised, and the skin can become sensitive. We often see colour changes becoming more visible in the way of pigmentation or erythema. Keratinocyte and melanocyte cells become larger and are not as active in protecting the mature skin like they did for the youthful skin. In summary, intrinsic ageing skin is characterised by epidermal and dermal atrophy, the quality of keratinocyte and melanocyte cells, flattening of the epidermal/ dermal junction, a decrease in vasculature and disruption to the barrier function which increases the incidence of inflammation and skin disorders.
EXTRINSIC AGEING:
Extrinsic ageing of the skin can be controlled as it is a result of environmental damage. Extrinsic aging appears as a thickening of the cornified layer (outermost layer of epidermis), precancerous changes (an example is actinic keratosis), skin cancer, formation of freckles and sunspots, and huge losses of collagen, elastin, and glycosaminoglycans (GAGs). As a result of these processes, the skin becomes rough, uneven in tone, and wrinkled. Free radicals are caused by atoms stealing an electron which causes chemical changes to the cells. When electrons are pulled from other molecules, chemical structures and biological functions are altered. Environmental influences, such as pollution, smoking and ultraviolet radiation generate free radicals. Antioxidant enzymes and molecules, such as
vitamin C, vitamin E and carotenoid pigments can protect us from free radicals however damage will still occur. Reactive oxygen species (ROS) are a subset of free radicals that contain oxygen. They are unstable molecules that can easily react and impact on other molecules within a cell. If there is an increase in reactive oxygen species there will be damage to DNA, RNA, and proteins all of which will lead to atrophy of the cell.
GLYCATION:
Another threat to the skin is Glucose which is a fuel that is necessary for our bodies. It forms plastic-like molecules known as age-related glycation end-products (AGES) by crosslinking with proteins. These complexes hurt skin proteins by causing them to be more brittle and less elasticised. Due to the fact that the skin is the barrier between body and environment, ultraviolet radiation causes damage to DNA as well as molecules which results in the generation of free radicals making it the crucial factor in the acceleration of wrinkling skin. In conclusion, the features which characterise an ageing skin include wrinkles, dryness of the skin, reduced skin thickness, loss of elasticity, dermal and epidermal atrophy, reduced rate of epidermal cell proliferation and cellular senescence. External factors that mainly contribute to skin ageing include sunlight, UV radiation, chemicals, pollutants, and smoking. Understanding the layers of the skin, intrinsic and extrinsic ageing, and glycation together with the knowledge of the signs of an ageing skin can support the modalities and active topicals that will support and maintain the health of an ageing skin. www.gaywardle.com
