Sun and the skin
Sun and Skin
The two types of rays that reach the earth are UVA and UVB. Although the sun is beneficial in many ways it causes skin damage and cancer. Remember winter sun can be as dangerous as summer sun.
The sun causes the skin to thicken and develop a leathery, coarse appearance. The sun weakens the skin’s elasticity which results in sagging and wrinkles, can also cause dark pigmentation patches and scaly growths called solar keratoses. Skin cancer is on the increase and is responsible for more than 2500 deaths per year.
Certain drugs such as antibiotics, accutane, medicated soaps and birth control pills make the skin more vulnerable to sun damage. Fragrances in cosmetics like lime oil, bergamot and perfume are photosensitive and can cause pigmentation damage to the skin.
You should always use a sun screen every day.
Immediate effects of sunlight on the skin
Erythema
Results from the dilation of blood vessels in the dermis. Excess erythema can cause swelling and pain. Blisters may form, epidermal cells may be destroyed and the surface of the skin can peel off
Increased cell production
After irradiation the cells increase their production rates in the epidermis by 6 -7 times. This could carry on for 4 weeks resulting in thickening of the epidermal layer. Sun exposed skin can double in thickness and the cells becomes disorganised. The cells lose their regular alignment and clump together forming uneven thickening of the skin’s surface.
Melanin production
Melanocyte cells increase their production of melanin pigment and introduce this melanin to the surrounding epidermal cells which engulf the melanin pigment and therefore darken in colour. This production continues for 2-3 days and the tan will continue to darken. This delayed form of tanning is responsible for pigment damage that is often seen after repeated sun exposure ie solar lentigines (liver spots).
Photo-sensitivity
Certain drugs make the skin photosensitive and can cause pigmentation. Some skins are naturally very sensitive to the sun and develop severe itching rash, headaches and nausea.
Long term damage affects the dermal layer of the skin. Because the dermis is living, damage is permanent and visibly obvious.
Approximately 80% skin damage occurs before age of 18.
Long term damage
Surface appearance
Skin’s texture feels rough to touch and is deeply hyperpigmented. Looseness is clearly visible.
Solar comedones
Solar comedones and cysts caused by damage to the sebaceous glands and follicles. The follicles fill with thickened oily sebum and hardened skin cells. This results in deep nodular comedones and cysts in multiple lesions across the cheeks and around the eye area.
Fine and coarse wrinkling
Results in thickening of the dermis and a thickening of the collagen and elastin protein fibre bundles. Free radical damage occurs and all in all fine lines and deep wrinkles appear.
Changes in dermal blood vessels
Dermal vessels become dilated, twisted and leaky. They thicken due to the accumulation of material in the blood vessel walls. Permanent couperose and erythema develop. Large blood spots may appear particularly in the ear area and lower lip.
Skin cancer
- Basal cell carcinoma accounts for 76% of all malignant skin tumours. Formed in the keratin-producing basal cells of the epidermis. If left can become an invasive tumour and attack subcutaneous tissue, bone, cartilage and nerve structures.
- Squamous cell carcinoma accounts for 19% of all skin cancers. Develops from pre-cancerous small macules when buds of abnormal keratin cells extend deep into the dermis and grow. Lesions form primarily on areas exposed to sun.
- Malignant melanoma -accounts for 5% of all malignant skin tumours. They are not restricted to body sites exposed to the sun nor are they associated to outdoors, sun exposed work occupations. Frequently seen on the back and lower extremities. Linked with a history of sunburns, particularly in childhood
There is a course that professionals in this sector can complete online to help with the detection of skin cancers. Use this link to access MASCED – Melanoma And Skin Cancer Early Detection Online Course if you are interested in expanding your knowledge.