Sunshine

Sunshine

22 May 2017, 6:00AM
Triathlon New Zealand


Sunshine is one of the appealing aspects of outdoor sports in general and multisport in particular. Sunlight warms us, brings colour and light to our surroundings and makes us feel good. 


We are a daytime animal with great full colour daylight vision but poor monochromatic night vision. We also are a hot weather creature, with little hair, a large surface area and an ability to sweat profusely, all unique features that adapt us best to a warm and sunny climate.

When the sun goes down our pituitary glands release both melatonin to make us sleepy and anti-diuretic hormone to reduce urine production so we can sleep the night undisturbed. We clearly are optimised for both light and warmth and we search for sunlight almost instinctively as opposed to nocturnal animals which avoid the light and await the dark and cool of night to be active.

I suspect it is for these deep seated evolutionary reasons we love the light and the sun and why the light and bright outdoors do make us feel good is because this is our preferred natural environment. We also need sunlight on our skin to make Vitamin D and this is possibly the reason some of us have whiter skins, allowing sunlight to penetrate more easily deeper into our skin where vitamin D is made.

This is the catch, the same adaption which allows light to penetrate more easily also makes the skin more easily damaged by light rays, be it by UVA UVB or UVC. Dark skinned people need more sun exposure to make Vitamin D, yet are far less likely to get sun damaged skin. It probably fits with light skinned people having origins in northern latitudes where sunlight is weaker therefore the advantage of better Vitamin D production outweighs the negative effects of sun damage. It is not certain that this is the whole explanation but it is clear that fair skinned people are far more susceptible to sunburn, premature skin aging with sun exposure and all skin cancer types.

"I can remember deliberately going out to sunbathe as a kid and applying coconut oil as a kind of baste! Burning and peeling after sunbathing at the beach or public baths was routine."

Clothing has altered this as well, it means that the sun exposure we do get is limited to the same skin areas time after time. Our heads and especially our faces along with our hands are the only body parts routinely exposed to the sun and it is no surprise that’s where we see the most sun damage accumulating.

Sun damage can be short term or long term. Short term causes sunburn which can be severe enough to cause serious pain and blistering. Everyone has had some sunburn at some time but there has been a dramatic change in our attitude towards avoiding sunburn in my lifetime.

I can remember deliberately going out to sunbathe as a kid and applying coconut oil as a kind of baste! Burning and peeling after sunbathing at the beach or public baths was routine. Photos from the sixties and seventies of cricket spectators show a horrendous display of uncovered burnt red flesh and it is great that these attitudes to sun exposure have changed so dramatically.

Today people are much more educated about the dangers of sun exposure and I suspect this will have laid the foundation for lower skin cancer rates in the future in the same way smoking reduction in the last 20 years is now causing a significant drop in lung cancer rates. However at present we are seeing the sun damaged skin and skin cancers that are a consequence of those times. Multisport athletes may be even more at risk because of their love of the outdoors.

Sun damage comes in three forms
1) Skin ageing
The skin looks older early, drier with more wrinkles and a blotchy thinned appearance that cuts easily and bruises readily. This can be reduced by preventing any further sun damage, moisturising daily and perhaps using retinol creams and in the most severe cases the use of ablative treatments like liquid nitrogen or skin peels of various types. These more aggressive treatments work by killing the top layer of skin triggering a healing response with new therefore younger skin growth. Typically they cause a fair amount of blistering & inflammation caused by the toxic chemical, extreme cold, or laser that causes the initial controlled peel. Seek an expert (dermatological or plastic surgical) opinion as these treatments can also cause scarring, infection and a red appearance. Retinol creams do work in a much milder fashion by increasing cell turnover and growth but in turn can make the skin even more sensitive to sunlight.


2) Benign skin cancers
Cancer and benign are words that don’t usually go together. All cancers grow and can invade surrounding tissues and require removal or destruction. The commonest skin cancers are basal cell carcinomas (BCCs) or squamous cell carcinomas (SCCs) and although they can grow rapidly it is very rare for them to spread distantly or metastasize. Hence they called benign although they remain a cancer that needs to be taken seriously.

They are commonest on sun exposed areas like the head neck and hands. Frequently they appear like a sore that won’t heal and are tender and sensitive. Often they are flesh coloured and may be rounded with a humped pearly raised periphery. They may have a central core or scab and often may look like a tiny volcano.

BCCs and SCCs are nearly always irritable so tend to draw your attention, any sore that doesn’t heal and that has some thickness to it needs to be examined by your GP or Dermatologist. Treatment can be biopsy to diagnose but often its best to excise completely as then it is gone and the laboratory can confirm the excision is complete and give certainty to the diagnosis. No one ever has only one BCC or SCC in their life so extra care and regular checks are needed afterwards. Sometimes treatment with liquid nitrogen or chemotherapy creams (efudix, aldara) can be very effective for more extensive areas or tiny lesions but lack the certainty and confirmation that surgical excision gives.

3) Malignant Melanoma
Melanomas are a malignant skin cancer in that they tend to metastasize early and spread or seed to distant sites. Despite recent treatment advancements the prognosis for malignant melanomas that have spread is grim. The cure rate however for early or thin melanomas is excellent, in the order of 99% cure by simply excising. The key is to detecting and removing melanomas while they are superficial, before they spread to the deeper layers of the skin where distant spread becomes increasingly likely. Because melanomas don’t hurt or irritate until they are likely to have spread visual detection is vital, and because they can grow over months visual inspection needs to be fairly frequent, ideally every two or three months. Mole maps are effective but are never going to be frequent enough to detect all melanoma changes.Self examination, ideally with your partner to check your back, is ideally done every two or three months and it is important to have some idea what you are looking for.

Melanomas are defined by the presence of melanin which is a black skin pigment, almost all melanomas contain some black. A cancer is also defined by chaotic cell growth so a melanoma is usually irregular in shape and in profile (unevenly raised). The edges are often not well defined and may show flaring or spreading. The chaotic growth also means that other colours (red brown white grey) may also be present. Have a look under “melanoma images” on google to get an idea. Cancers grow fast so a new mole or a mole that’s getting bigger may be a melanoma. If this is all too confusing a melanoma will be different from all your other moles. it’s indeed the “Ugly Duckling” mole.

Any uncertainty should mean a visit to your GP or Dermatologist, sometimes the only way to be sure is to remove the mole and have it sent to the laboratory for accurate diagnosis. As a result most suspicious moles turn out not to be melanomas at all, or at worst, very early melanomas.

Melanomas are more likely on sun damaged skin but can occur anywhere that has been sunburnt once. Sometimes melanomas occur on soles of feet, under nails, on scalps or backsides, so make sure when you examine your skin you examine everywhere. A “selfie“ of a mole with perhaps a ruler next to it to judge size is a good way to check to see if a mole is growing or changing between self examinations.

We love the sun but it doesn’t love us!

Originally published in New Zealand Triathlon & Multisport Issue 106, October 2016.

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