Fair-skinned people are known to be at higher risk for skin cancer and other problems associated with too much exposure to the sun. But people with skin of color are also vulnerable to the harmful effects of ultraviolet rays emitted by both the sun and indoor tanning beds, said Dr. Adam Friedman, director of dermatologic research, division of dermatology, Montefiore Medical Center in New York.
"Darker skin has more reactive melanocytes, or pigment-making cells, and has more and stronger melanosomes, which are small packets that contain skin pigment, both of which provide some inherent protection against UV rays but not enough, he said. "This unique biological difference in darker skin causes the harmful effects of UV exposure to occur more slowly in people of color, and the effects require more direct sun exposure. But the damage does happen, from cosmetic problems such as premature aging of the skin to serious conditions such as skin cancer."
"There are three major misconceptions that I encounter with my patients in the Bronx," Dr. Friedman said.
• Darker skin makes one immune to the harmful effects of the sun.
• There is no risk of exposure on cloudy days.
• One needs to get vitamin D via sun exposure.
"All three are completely false, and ultimately they perpetuate and result in improper skin protection," he noted.
"Skin cancer is rarer in people with skin of color, but it does occur and can be extremely serious when diagnosis is delayed," Dr. Friedman said. For example, melanoma, the most deadly form of skin cancer, is more than 20 times more common in whites than in African Americans, but people with darker skin are at greater risk of late diagnosis with advanced, thicker melanomas and lower survival rates. In fact, the overall 5-year melanoma survival rate for African Americans is only 77%, versus 91% for Caucasians, he said.
"I advise all of my patients to routinely check their own skin for any changes in appearance, and to see a dermatologist annually for a full body exam," Dr. Friedman emphasized.
Traditional sunscreens, especially those containing mineral-based agents such as titanium dioxide and zinc oxide, do not blend well when used on darker skin. The resulting chalky appearance is unacceptable to many patients, Dr. Friedman said. Fortunately, new formulations are changing that.
The newer sunscreens combine several agents to both decrease the concentration needed of each and allow for a synergistic effect between them, "ultimately offering a better sunscreen formula that can blend well into any skin type," said Dr. Friedman. Patients should look for products containing micronized or nanosized zinc oxide or titanium dioxide, which do not scatter light in the visible spectrum (to which older versions of these products owe their chalky appearance) but are highly effective at blocking UV radiation, he advised. Products that combine these mineral agents with multiple chemical blockers such as ecamsule, avobenzone, and cinoxate are particularly effective and cosmetically acceptable. Patients may be most likely to use sunscreens that utilize vehicles that enhance dispersal of these ingredients to limit clumping and phase separation, such as talc and Bentone gel.
In addition, pH stabilizers such as dimethicone are important, as the skin acidity in skin of color is lower and needs to be maintained to prevent degradation of skin adhesion proteins. Dr. Friedman recommends that his skin of color patients use SPF 30 broad-spectrum sunscreen, generously applied, and lip balm with an SPF of at least 30.
Dr. Friedman often hears from patients that they avoid sunscreen because it prevents them from getting vitamin D from the sun, which they believe is the best source. "You can enjoy the best of both worlds – use sunscreen when you spend time outdoors and take a vitamin D supplement, which is a very effective way to get adequate daily intake," he said. He advises his patients to remain vigilant about how much sun exposure they get. "Sunscreen alone is not enough to protect you from skin cancer, especially between the hours of 10:00 a.m. and 2:00 p.m. I encourage all of my patients to seek shade during that time of day and wear hats, sunglasses, and protective clothing if possible," he said.
Dr. Friedman had no financial conflicts to disclose.
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