Dark skin types prone to acral pigmented lesions

A new study suggests patients with darker skin types are more prone than those with lighter skin to acral pigmented lesions, and many people are unaware those lesions exist.

Researchers from NYU Langone Medical Center 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. Patients coming to these urban outpatient dermatology clinics in Manhattan, the Bronx, and Miami are commonly minorities.

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In their study, published online Dec. 14 in the Journal of the American Academy of Dermatology, senior author Jennifer Stein, M.D., Ph.D., associate professor of dermatology at NYU and colleagues found, overall, 36 percent of patients studied had acral pigmented lesions, with 391 of those lesions on patients’ palms and 278 on their soles. While 30 percent of non-Hispanic white patients had acral pigmented lesions, 40 percent of those with darker skin types had the lesions. That’s a 33 percent relative difference between the groups.

Looking more closely at patients’ skin types, the researchers found 44 percent of patients with Fitzpatrick scale types IV-VI had the lesions compared to 28 percent of patients with skin types I-II.

Acral melanocytic lesions were associated with higher mole counts, especially among minorities, according to a study press release.

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“We found similar benign dermoscopic patterns in darker skin and lighter skin, such as the parallel furrow, lattice and fibrillar patterns. We did note many lesions with a homogenous pattern on darker skin types. These may represent lentigines, which are common on darker skin. We did note two parallel ridge pattern lesions on darker skin, which were biopsied and found to be atypical nevi,” Dr. Stein told Dermatology Times.

Patient awareness about these lesions was a concern. While slightly more than half, or 54 percent, were aware of a pigmented lesion on one of their palms, only 43 percent with lesions on their soles knew they were there.

Dr. Stein said there are several takeaways for dermatologists, including:

• Acral pigmented lesions are very common.

• The vast majority of them are benign. 

• People with darker skin seem to have more acral pigmented lesions. Some of these lesions may be lentigines.

• Many patients are not aware of their acral pigmented lesions.

• A total body exam should include the hands and feet.

• Dermatologists should use dermoscopy when examining acral lesions. “The patterns are usually very clear and will save you unnecessary biopsies on the many acral lesions that you are likely to encounter,” Dr. Stein said.

• Always look out for and do not ignore the parallel ridge pattern on dermoscopy. “It is highly specific for acral melanoma,” she said. “Though it is unclear what the relationship between acral melanoma and atypical acral nevi is, there is a study from Japan that showed some atypical acral nevi with the parallel ridge patterns had cyclin D1 mutations.”

This study, funded by the Skin Cancer Foundation, supports educational outreach for people with dark skin types about these lesions, including attention to dermatologic evaluation and self-monitoring, according to Dr. Stein.

Disclosure: Dr. Stein reports no relevant disclosures.