People with darker skin types more likely to have pigment "spots" on palms and soles

People with darker skin types are 33 percent more likely to have pigmented lesions on their soles and palms and should be evaluated to ensure the lesions are benign.

These are the findings of a study led by researchers from NYU Langone Medical Center and published online in the Journal of the American Academy of Dermatology.

The study authors hope the findings raise awareness and persuade more people to get evaluated by dermoscopy. This is a procedure in which a specially trained physician takes a magnified look at acral lesions, searching for irregularities that are not always visible to the naked eye. While most are benign, some will need to be regularly monitored by a dermatologist.

"Acral pigmented lesions have not been well studied in people with darker skin," said senior study author Jennifer Stein, MD, PhD, Associate Professor in the Ronald O. Perelman Department of Dermatology at NYU Langone. "In rare cases, an unusual lesion like this can be an aggressive melanoma." Jamaican reggae musician Bob Marley, for example, died from acral melanoma, which was first diagnosed under his toenail.

The NYU-led study provided a rare snapshot of patients coming to three urban outpatient dermatology clinics in Manhattan, the Bronx, and Miami, which commonly treat minorities.

In the new study Dr. Stein and colleagues evaluated the palms and soles of 1,052 patients who came to dermatology clinics in New York City and Miami between October 2013 and April 2015. Overall, 379 of 1,052 patients (36 percent) had acral pigmented lesions, with 391 lesions on palms and 278 on soles. Thirty percent of non-Hispanic white patients had this type of lesion, compared with 40 percent of patients with darker skin types. This represents a 33 percent relative difference between the groups.

The contrast in acral lesion frequency was even greater between patients with the lightest and darkest skin types as defined by the Fitzpatrick scale, a standard measure that divides skin color into six types based on response to the sun. Forty-four percent of patients with dark skin (types IV-VI) were far more likely to have acral pigmented lesions compared to 28 percent of patients with lighter skin (types I-II). Acral melanocytic lesions were also associated with higher mole counts, especially in minorities.

Patient awareness of the presence of acral pigmented lesions was wanting. The study revealed that 54 percent of patients knew they had a pigmented lesion on one of their palms, and that just 43 percent with a lesion on their sole knew it was there.

"Awareness of skin cancer risks in this group support educational outreach to people with dark skin types, including attention to dermatologic evaluation, as well as self-monitoring," Dr. Stein said.

Along with Dr. Stein, NYU coauthors were Reshmi Madankumar, Priyanka Gumaste, Kathryrn Martires, Panta Schaffer, Miguel Sanchez and David Polsky.