Denver is the third smartest city when it comes to preventing and detecting skin cancer, according to a new survey by the American Academy of Dermatology.

Good thing because the city receives roughly 25 percent more ultraviolet (UV) light than those closer to sea level. “Our UV exposure in Colorado can easily double our risk for skin cancer,” says Nicole Annest, MD, board-certified dermatology surgeon with Kaiser Permanente Colorado.

Below Dr. Annest shares ways to prevent and detect sun damage and skin cancer, which is the most common form of cancer in the United States. But first, a lesson on what you’re fighting against.

UV light and your skin
UV radiation’s short wavelengths, known as UVB rays, stimulate the body to produce pigmentation known as melanin. Although this may create a nice suntan, it’s really the body’s attempt to protect itself from further damage.

Long wavelengths, or UVA rays, penetrate the deeper layers of the skin and damage connective tissue and blood vessels. Both types of UV radiation not only increase the risk of skin cancer, but can also cause premature aging and suppress the body’s immune system.

“UV rays damage the structure of the skin, which can cause sun spots, sagging skin, and wrinkles,” says Dr. Annest, who specializes in Mohs micrographic surgery for skin cancer. “UV rays also damage the cells of the skin. That damage can accumulate over time and lead to skin cancer.”

The three most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. Skin cancer warning signs can include a new growth or mole, a change in a growth or mole, a sore that does not heal, or irritation of the skin.

Prevent and detect sun damage
So what can you do about it?

• Recognize the signs and symptoms. Examine your skin once per month for new skin growths or changes in existing moles, freckles, or bumps. Knowing the ABCDEs of skin cancer will help you recognize the signs and symptoms of the disease in its early stages when it’s most treatable.
   
• Avoid peak sun hours. Limit outdoor activities between 10 a.m. and 4 p.m. when the sun is the strongest – even when it’s cloudy. “Remember: the sun can be just as damaging when it is blocked by clouds,” Dr. Annest says. “Even brief periods of repeated sun exposure can add up and be more harmful than spending a day at the beach or out on a hike.”
   
• Check your meds. Some prescription medications and over-the-counter drugs, including antibiotics; certain cholesterol, high blood pressure, and diabetes medications; and immune suppressing medications can increase your sensitivity to the sun. Take extra precaution or avoid the sun if you take these.
   
• Apply (and reapply) sunscreen. “Sunscreen needs to be reapplied about every two hours for it to maintain the sun protection factor (SPF) listed on the bottle,” says Dr. Annest. Use a broad-spectrum sunscreen that protects against UVA and UVB exposure with an SPF of 30 or higher. A shot glass full of sunscreen should cover the whole body, including areas you might overlook like your lips, ears, nose, and neck.
   
• Call your physician. If you notice changes to your skin, make an appointment with your doctor. “Start with your primary care doctor to get a thorough initial screening,” Dr. Annest recommends. “They can determine if the condition is serious and refer you to a dermatologist.”

Test your “sun-telligence” by taking our sun safety quiz at kp.org.

Dr. Annest received her medical degree from the University of Colorado Health Sciences Center. She completed her residency at the University of Iowa and her fellowship in Mohs surgery and Procedural Dermatology at the Scripps Clinic and Research Foundation.