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Dermatology Facts—Sun ProtectionExposure to the sun has been associated with melanoma, non-melanoma skin cancers (basal cell and squamous cell carcinoma), and photo-aging (wrinkling, fragile skin, and spotty dyspigmentation (so called “liver spots”). Both melanoma and non-melanoma skin cancers are more common in those with light skin, light hair, and blue eyes, those who sunburn easily, suntan poorly, or freckle with sun exposure. There is good evidence that the risk of both melanoma and non-melanoma skin cancers is increased with increased UV exposure, although they differ in the way that UV exposure causes them and this influences prevention. Non-melanoma skin cancers are most strongly related to lifelong chronic UV exposure, whereas melanoma correlates best with episodic UV exposure and blistering sunburns. UVA & UVBThere are two forms of ultraviolet (UV) light to protect against: UVA and UVB. UVA is present throughout the entire day (not just the peak sun hours), and comes through glass and clouds. UVA plays a key role in skin wrinkling, leathering, and skin cancer promotion. UVB are burning rays present in greatest amounts during midday. UVB rays play a major role in skin cancer promotion and photoaging. SunscreensThe sun protection factor (SPF) number on the sunscreen lotion is a guide as to how long you can stay in the sun before risking sunburn. Recent studies have shown that most people apply sunscreens too thinly and therefore the SPF is probably less than what it says on the bottle. “Waterproof” on the sunscreen label indicates that the protection is effective for four 20-minute swims. “Water resistant” is effective for two 20-minute swims. Reapply more frequently if perspiring excessively or toweling off frequently. Whichever form of sunscreen is chosen, it must be applied 20 to 30 minutes before being exposed to the sun. A new component of sunscreens, Parsol or Avobenzone, extends the protection from UVA and is advisable. Choosing a sunscreen is an important part of your complete sun protection program but remember it is only one part! Sunscreens are typically divided into two broad categories: physical and chemical. Physical sunscreens such as titanium dioxide and zinc oxide actually reflect and scatter ultraviolet light, while chemical sunscreens act as protective filters by absorbing ultraviolet light. Patients with sensitive skin may benefit from using sunscreens with no dyes or perfumes. Patients with acne or oily skin should use sunscreens that include “hypo-comedogenic or non-comedogenic” on the label. These words mean that this product will be less likely to clog skin pores and contribute to acne. Types of Sunscreen Vehicles
Recommendations for proper sun protection
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