Skin Care Science

The skin is the body’s outer protective cover. It is made up of 3 layers – epidermis, dermis and fat. The most superficial layer is called the epidermis. The living cells produced by the lower levels of the epidermis are slowly pushed to the surface. Cells, when they reach the surface, have become harder and drier and contain keratin – a substance which helps protect us from heat and cold. The epidermis also contains specialist cells called melanocytes. These produce the dark skin pigment melanin, which gives our skin some protection from burning

MOLES AND FRECKLES

Moles occur where melanocytes clump together. They are usually oval or round pigmented spots, with a smooth border and regular colour. They may be hard or raised and clump together.

Freckles are flat and usually occur on sun exposed areas. Moles and freckles are very common in fair skinned people; 20 – 40 are the average number of moles for an adult. Most appear around puberty, in later life many may disappear.

ON THE BRIGHT SIDE

Exposure to sunlight allows our bodies to produce vitamin D. For most white skinned people, 10-15 minutes exposure of face, forearms and hands to our Northern Ireland sunlight is enough to maintain vitamin D levels. (The closer to the equator fair skinned people go, the shorter the exposure time required). However people with dark or heavily pigmented skins, living in northern latitudes may benefit from more moderate sun exposure to ensure maintenance of adequate vitamin D levels. Prolonged exposure to UV radiation is bad for all skin types.

HOW SKIN PROTECTS ITSELF

The sun’s UV radiation on our skin causes it to try to protect itself by producing melanin. This production of melanin in response to trauma from UV radiation appears as a ‘tan’. The skin also defends itself through thickening of the outer epidermis – keratin layer. Now we can understand the origins of the word ‘tan’ – thickened and darkened skin – leather like. A ’suntan’ indicates sun damage.

ADVERSE EFFECTS OF UV RADIATION ON THE SKIN

Short term: skin exposed to UV radiation can develop freckles and rashes. Short-term excessive exposure to UV radiation causes sunburn – reddening, pain and in severe cases blistering and even second degree burns.
Take care not to burn. Sun increases your risk of skin cancer.

Exessive sun exposure resulting in sunburn – three weeks on. (left)

Long term: over time UV radiation exposure, whether or not associated with sunburn, accelerates skin ageing making it look dry, wrinkled, loose and dull and causing pigment changes commonly known as ‘age spots’. It can also cause changes in the skin cells, which may lead to skin cancer.

Excessive sun exposure is the main cause of most types of skin cancer.

These two photographs are of two 71 year old women. They look very similar, except that one has spent a great deal of her life exposed to the sun, whereas the other has covered up.

SKIN MOST AT RISK

Some skins are more at risk from the effects of UV radiation than others. Check yours out:

MOST RISK

•     Fair skin that never tans – always burns.
•     Fair skin that burns before tanning.
•     Skin that always tans and rarely burns
•     Dark and heavily pigmented skin which would only burn in exceptional circumstances.

LEAST RISK

Those with pale skin, fair or red hair need to take special care.