The Skin in the Sun
Ultraviolet Radiation
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UV radiation is part of the electromagnetic (light) spectrum that reaches the earth from the sun. It has wavelengths shorter than visible light, making it invisible to the naked eye.
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These wavelengths are classified as UVA, UVB, or UVC.
Ultraviolet Radiation and its relationship to our skin
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The evidence is clear that sun damage is a substantial risk factor for skin cancer
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UV radiation damages the skin's cellular DNA and produces genetic mutations that can lead to skin cancer. The World Health Organization has identified UV as a proven human carcinogen (a substance or exposure capable of causing cancer in living tissue)
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UVB is what causes skin reddening and sunburn, thereby contributing to tanning and photo-aging.
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The way a tan works is actually by causing injury to the skin's DNA. The skin then darkens as a defence against further DNA damage. This defence, like many human defences can lead to consequences, and in this case this can be skin cancer.
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Tanning booths primarily emit UVA. The high-pressure sunlamps used in tanning salons emit doses of UVA as much as 12 times that of the sun (Skin Cancer Foundation data).
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UVA and UVB also suppress the immune system, reducing your ability to fight off these and other maladies.
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This ultraviolet radiation also plays a role in eye damage and is implicated in diseases such as cataracts.
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We therefore need protection from both UVA (I and II) and UVB.
Sun Protection Strategies
Seeking shade
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Peak UV radiationtimes here in the west coast of Canada are between 10am-2pm. Seeking the shade at these times is generally a good idea.
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Newborns should be kept out of the sun or at least exposure be minimised. Cover and shade them appropriately.
Harm reduction strategies
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We should all dress to limit UV exposure
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Special sun-protective clothes with UPF (ultraviolet protection factor) indicate how much UV radiation can penetrate the fabric; the higher the UPF, the more protection.
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Bright- or dark-coloured, lustrous clothes reflect more UV radiation than do pastels and bleached cottons.
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Tightly woven, loose-fitting clothes provide more of a barrier between your skin and the sun.
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Broad-brimmed hats and UV-blocking sunglasses help shield the sensitive skin on your head, neck, and eyes. These are areas that usually sustain a lot of sun damage.
The Lowdown on Sunscreen
What does sunscreen do?
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We should all dress to limit UV exposure
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SPF is not an amount of protection but it indicates how long it will take for UVB rays to redden (burn) skin when using a sunscreen, compared to how long skin would take to redden (burn) without the product.
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E.g. someone using a sunscreen with an SPF of 15 will take 15 times longer to redden (burn) than without the sunscreen.
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When it comes to Pediatrics, many dermatologists recommend ≥SPF 50 be used.
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Since both UVA and UVB are harmful, you need protection from both kinds of rays.
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In addition a sunscreen should have some combination of the following UVA-screening ingredients: stabilized avobenzone, ecamsule (a.k.a. MexorylTM), oxybenzone, titanium dioxide, and zinc oxide.
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Terms often seen on labels include ‘multi spectrum’, ‘broad spectrum’ or ‘UVA/UVB protection’.
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It should be known that there is no consensus on how much protection these terms indicate.
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Most UV filters are chemical: They form a thin, protective film on the surface of the skin and absorb the UV radiation before it penetrates the skin.
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The physical sunscreens are insoluble particles that reflect UV away from the skin.
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Most sunscreens contain a mixture of chemical and physical active ingredients.
How to use Sunscreen
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Use on unexposed skin.
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Apply generously. Less is not more.
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Apply 0.5-1 ounce (1-2 tablespoons) of sunscreen to your child’s entire body 30 minutes if possible before they go outside. This is approximately 2mg/cm2
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Reapply the sunscreen every two hours, or immediately after swimming or excessive sweating.Remember, no product is fully waterproof.
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Despite what you may read, many vehicles (different screens) can be left down to patient choice and preference. Simply ensure that the choice meets the requirements needed for protection.
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For Patients with eczema, they may find some brands irritate more than others.
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Beware of “natural” products that may nothave sun-screening agents in them; always check the label.
Spray vs. Lotion
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When it comes to the choice between sprays and lotions, lotions offer more protection because you can tell how much you are putting on your child’s skin.
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On average, people tend to get less sunscreen out of a spray because they only spray for a couple of seconds.Overall, sunscreen lotion is the best way to go and spray is not recommended.
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However if spray is the only sunscreen you have on hand, make sure to spray the sunscreen onto your hands and then rub it onto your child’s skin and face.
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Be sure to avoid getting the spray into the eyes or mouth.
Sunscreen Use < 6 months of age
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“Babies under six months of age should be kept out of direct sunlight. If adequate clothing and shade are not available, sunscreen may be used on small areas of the body, such as the face and the backs of the hands.”
Take care and love the skin that you are in. - Dr. Kevin Ansah
*Also remember the sun not only burns, it heats. With prolonged heat, dehydration follows. Hydration will be key.*