(HealthDay) -- Skin cancer is more common among white people, but people with darker skin are also at risk, a dermatology expert cautions.
While the skin pigment melanin does offer people with dark skin some natural protection against harmful ultraviolet rays and sunburns, this protection is not perfect and too much sun exposure over a lifetime can lead to a high risk for skin cancer, said Dr. Valencia Thomas of the Harris County Hospital District, in Texas.
Using sunscreen with a high sun protection factor (SPF), regularly checking your own skin and having yearly skin check-ups are important for preventing skin cancer or catching it early if it does occur, Thomas advised.
One in five Americans will be diagnosed with skin cancer this year, according to the American Academy of Dermatology. Over the past 30 years, rates of the deadliest form of skin cancer -- malignant melanoma -- have increased among all races in the United States. The disease kills 22 people a day across the country.
"In African American and Asian populations, malignant melanoma is most commonly located on hands and feet, while among Caucasians [whites] and Hispanics, it's found on the legs and back," Thomas said in a hospital district news release.
"Although excess ultraviolet radiation is a risk factor for developing malignant melanoma in Caucasians, the role of these rays among ethnic populations is not well known. People with new or changing moles that have irregular borders, color and appear bigger than a pencil eraser should get them examined immediately," advised Thomas, who is director of dermatology at the Lyndon B. Johnson General Hospital and Quentin Mease Community Hospital, and an assistant professor at the University of Texas Health Science Center, in Houston.
Other common types of skin cancers are basal cell carcinomas and squamous cell carcinomas. Basal cell carcinomas appear as a growing bump with blood vessels, which tend to bleed easily and in ethnic populations may be dark brown or black. This type of cancer tends to appear in the head and neck area. Basal cell carcinoma is most common among Hispanics and Asians, and second most common among blacks and South Asian Indians.
Squamous cell carcinoma is most common among South Asians and blacks and appears as firm bumps, sometimes with thick scale. Among South Asian Indians and blacks, this type of skin cancer is found on the legs or the genital areas, Thomas said. This type of cancer is strongly linked to sun exposure.
Explore further: Melanoma a big threat to older men
The U.S. National Cancer Institute has more about skin cancer.