Skin Cancer in Dark Skin: What You Need to Know

Three factors create a perfect storm for late diagnosis. First, both patients and doctors have lower awareness of skin cancer risk in people of color — many believe dark skin provides complete protection. Second, skin cancers in darker skin often appear in unusual locations (palms, soles, nails, mucous membranes) that are not checked during routine exams. Third, clinical training materials overwhelmingly show skin cancer on white skin, making recognition on darker skin harder for providers.

The result: 52% of non-Hispanic Black patients and 26% of Hispanic patients are diagnosed with advanced-stage melanoma, compared to 16% of non-Hispanic white patients.

The distribution of skin cancer differs dramatically by skin color. In darker skin, melanoma most commonly appears on acral sites — areas with less melanin protection: palms of hands, soles of feet, under fingernails and toenails, mucous membranes (mouth, genitals), and the lower legs.

Basal cell carcinoma and squamous cell carcinoma in dark skin tend to appear on sun-exposed areas (same as in lighter skin) but also in areas of chronic scarring, burns, or radiation — locations that would not be suspicious in lighter-skinned patients.

The ABCDE criteria still apply, but with important modifications. Color (C) is harder to assess when normal skin pigmentation varies widely. Border (B) irregularity may be less obvious against darker skin backgrounds. Evolution (E) remains the single most important criterion regardless of skin color — any changing lesion deserves evaluation.

The ugly duckling sign may be more useful than ABCDE on darker skin: a lesion that looks different from everything else on your body, regardless of its individual features.

During your monthly self-exam, spend extra time on these areas: palms of both hands (look at every crease and between fingers); soles of both feet (use a mirror or ask someone to check); all fingernails and toenails (look for dark longitudinal streaks — the Hutchinson sign); inside your mouth (check gums, palate, inner cheeks); lower legs and ankles.

Any dark spot, streak, or non-healing sore in these locations that is new or changing should be evaluated by a dermatologist.

Bob Marley died at age 36 from acral melanoma that started as a dark spot under his toenail. It was initially dismissed as a soccer injury. By the time it was correctly diagnosed, the cancer had metastasized. His story illustrates two critical points: acral melanoma does not require sun exposure to develop, and delayed diagnosis — not aggressive biology — is what makes it deadly.

If you notice a dark streak under a nail, especially one that is widening or extends onto the surrounding skin (Hutchinson sign), see a dermatologist immediately.

If your dermatologist does not routinely examine your palms, soles, nails, and mucous membranes, ask them to. Request a full-body exam that includes acral sites. If a lesion concerns you and your provider dismisses it, seek a second opinion — you know your body better than anyone.

Bring photos of the lesion from when you first noticed it. Document any changes. Knowledge that skin cancer can affect dark skin — and where it tends to appear — is your most powerful tool for early detection.