SATURDAY, April 26 (HealthDay News) -- Shiny lip balms and glosses may attract ultraviolet rays and increase the risk of skin cancer, warns a dermatologist at Baylor University Medical Center at Dallas.

Dr. Christine Brown noted that protecting your lips from harmful sun rays is as important as using sunscreen to protect your skin. But a recent study found that less than 25 percent of Americans use some form of lip protection.

Lips are more susceptible than skin to aging from chronic sun damage and also more prone to developing serious cancers.

"When skin cancer occurs on the lower lip, it has the potential to be much more aggressive and metastasize to surrounding lymph nodes," Brown said in a prepared statement.

Shiny balms and glosses don't offer protection. Instead, they attract the sun's rays to the lips.

"What most people don't realize is they're actually increasing light penetration through the lip surface by applying something clear and shiny to them," Brown said.

Women should only wear glossy lipsticks in the sun when they have a layer of sun protection on underneath, dermatologists advise.

Anyone who's planning on being outdoors for more than 20 minutes at a time should use a lip sun block with an SPF of 30. Women should apply it in the morning under any lipsticks or lip glosses and then reapply the sun block throughout the day.

People should check their lips for signs of cancer. Consult a dermatologist if you notice any changes to the color of the lip surface (an area turns opaque or white), or if you have persistent peeling or flaking of a spot on your lip, Brown said.