Many of us are far too familiar with the unsightly consequences of having too much fun in the sun (redness, possibly even swelling, blisters, and peeling of the skin), but what isn’t as obvious is the damage being done underneath the skin.
A sunburn is a preventable risk factor for accelerating aging of the skin and skin cancer. Dermatologists agree that the most effective way to keep skin looking young and healthy is to protect ourselves from the sun. With the season of long, sunny days upon us, let’s review why this simple bit of advice is important to adhere to.
A sunburn is an inflammatory response of the skin caused by excessive ultraviolet radiation (UVR) exposure. Both UVA (320 to 400 nm) and UVB (280 to 320 nm) wavelengths can induce a sunburn; however, UVB are the most successful at provoking erythema (superficial reddening of the skin) and DNA damage. The risk of a sunburn is inversely related to latitude; therefore, the greatest risk is closest to the equator, where UVB intensity is most significant. No matter how close to the equator you may find yourself this summer, remember that UVB intensity is highest everywhere between 10 a.m. and 4 p.m.
So what exactly is happening to the skin as it’s absorbing all this UVR? UV photons damage the bonds between the four nucleotides that make up cellular DNA (thymine, cytosine, adenine, and guanine). These damaged cells then undergo apoptosis (programmed cell death), which leads to a cascade of unfortunate events. Within 30 minutes, the superficial blood vessels under the skin begin to vasodilate. Blood, along with inflammatory mediators, rush to the site of damage to help with the healing process. As a result, we experience redness and painful inflammation of the skin.
The acute skin manifestations associated with sunburns typically resolve on their own within three to seven days. The damage that happens on the cellular level is not always as transient. Sometimes, UVR causes damage to the DNA repair process in a way that allows cells to mutate and acquire the ability to avoid dying, which leads to the disease process known as cancer.
Skin cancer is the most common form of cancer in the U.S. Susceptibility to a sunburn is a red flag for susceptibility to skin cancer; however, everyone, regardless of skin type, is at risk for the potential adverse effects of UVR. Therefore, the use of sunscreen should be a part of everyone’s daily skin-care routine. Broad-spectrum products with a sun-protection factor (SPF) of 30 or greater are recommended.
Sunscreen should be applied generously, repeatedly, and to all parts of the skin that are exposed to the sun. You can use the ‘shot-glass rule’ when applying sunscreen; studies have shown the average-size adult or child needs about the amount of sunscreen that it takes to fill a shot glass in order to evenly cover the entire body. Experts also agree that it is best for sunscreen to be applied 15 to 30 minutes before going out in the sun to allow formation of a protective barrier, and should be reapplied every two hours. Avoidance of the sun during peak daylight hours and the use of protective sunscreen are vital to keeping your skin young and cancer-free.
Melanoma, the deadliest form of skin cancer, is easily preventable. When sunscreen is used on a regular basis, we know that your chance of developing skin cancer decreases.
This summer, remember to protect yourself against the sun’s harmful UV Rays. Here are some great tips on how you can ensure you and your family are being sun-safe:
- Wear SPF 30 or above regularly, especially when outdoors, using a full 1-ounce portion to cover all exposed parts of your body;
- Be sure to rub the sunscreen in thoroughly and to reapply every two hours;
- Wear a hat, protective clothing, and sunglasses; and
- Don’t forget the tops of your ears, feet, and back of the hands.
IMPACT Melanoma, a national nonprofit aimed at reducing the incidence of melanoma, the deadliest form of skin cancer, is committed to sun safety. Recently, it conducted an independent national survey of 1,016 adults inquiring about frequency of sunscreen application by season, sunscreen preference, and opinions about free public sunscreen.
The results were in some ways anticipated, with 86% of participants always or sometimes using sunscreen during the summer months, but also surprising, finding a near-complete reversal of use between summer and fall, lower use of sunscreen in Southern states despite the warmer climates, and a concerning lack of use among African-Americans, even in summer months. Remember, is important to protect yourself all year, as the sun’s harmful UV rays are always present.