Cover Up to Cut Risk of Skin Damage from Sun's UV Rays

July 9, 2019

Whenever you’re outdoors this summer, be sure to take steps to prevent solar erythema, the acute cutaneous reaction to excessive exposure to ultraviolet (UV) radiation.

Translation: Don’t get a sunburn.

If you do allow the sun to bake, fry or broil your skin you’ll pay a price right away with painful redness, peeling and possible blistering. Those effects are short-lived, but sunburn can also generate long-term problems such as early aging of the skin (brown spots, wrinkles) and skin cancer.

“Skin cancer is one of the most preventable forms of cancer out there, and there’s greater overall awareness today that overexposure to the sun isn’t good for your health,” said Wake Forest Baptist Health dermatologist William Huang, M.D. “But we still see lots of people engaging in risky behaviors.”

For starters, how does a superhot sphere of glowing gases that’s 93 million miles away manage to damage our skin?

The sun emits many different forms of energy in waves of electromagnetic radiation, but about 99 percent of the ones that hit Earth are rays of infrared radiation (heat), visible light and ultraviolet (invisible) light. The UV rays have shorter wave lengths and therefore contain more energy than heat and visible light rays, and they’re the ones that can ravage skin.

Two types of ultraviolet rays reach us, UVA and UVB.

“UVA, which has the longer wave length of the two, penetrates deeper into the skin and contributes to premature wrinkling and aging,” Huang explained. “UVB doesn’t penetrate as deeply but has high-energy impact that damages surface skin cells and contributes more to sunburn. Both contribute to overall skin cancer risk.”

The skin does have a defense mechanism against the sun’s rays: melanin, the brown pigment that gives skin its color.

When the body senses the effects of UV rays skin cells called melanocytes produces additional melanin to absorb the radiation. A suntan indicates that response to the damage. Sunburn occurs when the impact of the sun exposure overpowers an individual’s melanin output. That’s why someone with very light skin (low melanin) might get a sunburn in 15 minutes on a sunny day while person with very dark skin (high melanin) may tolerate the same exposure for much longer.

But that doesn’t mean people with darker complexions are immune from the effects of exposure to UV rays. Even when it doesn’t burn the skin, UV radiation can cause damage and eventual mutations in the DNA of skin cells, which may lead to the formation of malignant tumors.

“In general the person at higher risk for skin cancer has fairer skin, is easily burned and has had a lot of sun damage over their lifetime, but we see skin cancer in people of all ages and skin types,” Huang said. “Ultraviolet radiation is a carcinogen. The relationship of ultraviolet radiation to skin cancer is stronger than that of smoking to lung cancer.”

And like the effects of cigarette smoke on the lungs, sun damage is cumulative.

“Sun damage follows you throughout your entire lifetime; skin never forgets the damage done to it,” said Huang, who is also associate professor of dermatology at Wake Forest School of Medicine and director of the department’s residency program. “Much of the skin cancer that we see in people in their 50s, 60s and beyond is from sun damage they had when they were in their 30s, 20s or even younger.”

Skin cancer is the most common form of cancer in medical care, accounting for more diagnoses – over 5 million a year in this country – than all other forms of the disease combined. It is estimated that 20 percent of all Americans will develop skin cancer at some point in their lives.

Fortunately, the most common types of skin cancer are not deadly the vast majority of the time.

The two most frequently diagnosed forms, basal cell carcinoma and squamous cell carcinoma, account for approximately 97 percent of all cases in the United States. Both are likely to appear on sun-exposed areas, can usually can be removed surgically and rarely spread to other parts of the body if caught early.

The third most common but most serious form of skin cancer is malignant melanoma, which affects approximately 200,000 U.S. residents annually and will kill an estimated 7,000 this year. It can appear on sun-exposed areas or parts of the body that get no sun at all and is far more likely to metastasize than the other forms.

“If you leave a melanoma unchecked long enough there is a high chance it will spread,” Huang said. “On the other hand, if a melanoma is identified early it can be removed without complications in most instances.”

The best way to guard against the development of skin cancer is to regularly examine your body for new bumps, spots, scaly patches or other anomalies and for changes in existing moles, freckles or birthmarks. Don’t be shy about asking a family member or someone else for help to check hard-to-see areas.

“If there’s something that doesn’t look right, you should see a medical professional,” Huang said.  “If a dermatologist is concerned that it could be cancerous, a skin biopsy is a quick and accurate way of finding out whether something is malignant.”

And the best ways to protect your skin from UV damage?

The American Academy of Dermatology recommends trying to limit exposure when the sun’s rays are strongest, generally between 10 a.m. and 3 p.m.; wearing protective clothing (long-sleeved shirt, long pants, wide-brimmed hat, sunglasses) whenever possible; using extra caution near water, sand, snow and concrete structures (which can reflect UV rays) and when at higher altitudes and tropical latitudes; avoiding tanning beds and sunlamps (which can do more damage than the sun); and generously applying a broad-spectrum, water-resistant sunscreen with an SPF of 30 or higher to all exposed skin whenever you’re going to be outside, even on cloudy days.

“When it comes to sunscreen, people in general don’t put on enough,” Huang said. “And they don’t put it on as often as they should.

“I tell my patients that it should become routine, like brushing your teeth. You’d feel strange if you didn’t brush your teeth every day, and it should feel strange if you’re not using sunscreen every day.”

Media Contact:

Wayne Mogielnicki, wmogieln@wakehealth.edu, 336-716-8043