Clearskincare – Corrective Skincare How to correct the commonest skin conditions Acne, Sun Damage & Pigmentation
The skin is made up of three layers:
The epidermis is the outer skin layer and functions as the skin’s protective barrier.
The dermis lies under the epidermis and these two layers are separated by the epidermal-dermal junction, a semi-permeable membrane, that allows the passage of some substances through into the dermis.
Beneath the dermis lies the subcutaneous layer, which consists of fat and blood vessels.
The dermis also contains hair follicles, sebaceous glands and sweat ( eccrine ) glands.
To successfully correct the commonest skin conditions, we need to concentrate on the epidermis and the dermis and understand their structure and function.
The epidermis is made up of 2 cell types:
Keratinocytes are protein cells which make up the majority of the epidermis and are arranged in layers above the cells in the basal layer.
New keratinocytes are made by division of keratinocytes in the basal layer of the epidermis.
As new keratinocytes are made, the cells in the layers above are pushed upwards towards the surface of the skin.
As the keratinocytes are pushed upwards, they begin to flatten and die.
By the time they reach the stratum corneum, the outermost layer of the epidermis, they exfoliate as dead skin cells.
This process of skin renewal occurs continuously in the skin and takes around 30 -40 days to complete.
Via this inbuilt renewal process the skin is able to ensure its protective barrier remains in optimum condition through its lifetime.
This barrier is so vital for the body’s health that we will die if we loose more than 50% of our epidermis.
We can degrade the effectiveness of the epidermal barrier through excessive UV exposure and excessive use of skin cleansing agents.
In normal skin, the number of new cells made in the basal layer is equal to the number of cells exfoliating from the skin’s surface.
The 2 nd cell type in the epidermis are the melanocytes.
The melanocytes are pigment producing cells which lie in the basal layer of the epidermis.
The number of melanocytes in the basal layer determines our genetic skin colour.
The role of the melanocytes is to protect the keratinocytes from mutation from UV radiation the skin receives during sun exposure.
Understanding this role is key to understanding why sun damage and abnormal pigmentation occur and how we can prevent and treat these skin conditions.
The melanocytes has long arms which stretch up into the upper layers of the epidermis, allowing them to make contact with many keratinocytes.
When the skin is exposed to UV radiation, the melanin granules contained in structures called melanosomes, migrate from the melanocytes into the surrounding keratinocytes. This is called a tan.
The melanosomes coat the nuclei of the keratinocytes, protecting them from the risk of mutation.
As these keratinocytes are pushed upwards to the surface of the skin, they exfoliate and the skin returns to its natural colour.
The number of melanocytes in each skin is a result of 1000s of years of evolution within each geographic region and UV radiation risk associated with that region.
If a skin type, with a melanocyte count evolved for one region, is then relocated to a region with a much higher UV exposure, the inbuilt melanin keratinocyte protective system can be very easily overwhelmed.
The first sign of this melanin protective system (MPS ) has been overwhelmed is vertical clumping of melanin. We call this a freckle.
Over time as the skin receives continued UV overexposure, melanin starts to horizontally clump, producing a chloasma type hyperpigmentation, which, unlike hormone induced chloasma, is very difficult to treat.
Following years of overexposure to UV, the melanocytes are completely overwhelmed and die, leaving small round patches of depigmented skin. This is evident on the forearms of most Caucasian Australians, over the age of 40.
Melanocytes can also overproduce melanin in response to hormones, skin injury, inflammation and some drugs.
The commonest reason for hyperpigmentation in the skin is UV overexposure and the second, scarring, in particular, acne scarring.
Some skin are more prone to hyperpigmenting than others and one theory postulates this is due to genetic mixing of different skin types eg Caucasian/Asian: African/Hispanic: Asian/Hispanic.
Collagen - makes up 75% of dermis. In healthy skin it is arranged in bundles in a “basket-weave” pattern, provides strength and prevents tearing, decreases as skin ages
Elastic fibers - composed of elastin, make up 5% of dermis, maintains skin tension and extensibility: decrease, fragment and loose their normal structure as skin ages. In sun exposed skin, increase, become thickened and dysfunctional.
Fibroblasts - master cells of the dermis which produce collagen, elastic fibers and the dermal matrix.
The Cosmetic industry has convinced us that skin ages as a result of skin dryness and moisturisers re-hydrate the skin to restore a youthful appearance and reduce wrinkles.
Moisturisers make the skin feel softer by filling in the spaces between exfoliating skin cells.
Moisturisers can exacerbate skin problems such as acne, rosacea, seborrhoea and clogged pores.
In order to treat and reverse skin ageing, we need to use treatments that have an effect on the dermis, and ultimately collagen and elastin.
Characteristics of Healthy Skin
Smooth because of undamaged and compact keratinocytes.
Firm with abundant functioning collagen and elastin
Evenly coloured due to properly functioning melanocytes
Properly hydrated due to richness in glycosaminoglycans
Has efficient and continual skin cell renewal
Has good blood supply
Repairs itself quickly when scratched, scraped or injured