Is hyperpigmentation dangerous?

What does hyperpigmentation look like?

Melanin is the pigment that gives skin its color. When the body makes too much, skin becomes darker. Pigmentation changes can affect small patches or much larger areas, and hyperpigmentation can affect any skin tone. The patches can look brown, black, gray, red or pink. Ordinary hyperpigmentation does not cause pain or itching; dark spots with other symptoms need assessment.14

What commonly causes dark patches?

Dark marks can remain after acne, a cut, a burn or another injury. This is called post inflammatory hyperpigmentation: extra pigment left after inflammation. Sun exposure, irritating skin or hair products, certain medicines and hormonal changes during pregnancy can also trigger dark patches. Finding the cause matters because treating ongoing inflammation or removing irritation helps prevent more marks.15

Which changes need a doctor?

Arrange a medical appointment for any of these changes:

• A spot or mole that changes size, shape or color, develops uneven edges, or has several colors.
• A mark that grows, bleeds, becomes crusty or itches.
• A sore that does not heal, or heals and returns.
• A new dark line in a nail, darkening around a nail, or a persistent rough or scaly patch.
• Skin that is painful, hot, red or leaking pus.
• Persistent darkening with no clear explanation, or discoloration that causes significant concern.

Contact a dermatologist promptly if a spot looks suspicious, and explain the change when booking. A new or unusual mark that remains after a few weeks also deserves a check. Skin cancer is easier to treat when found early; do not wait for a suspicious spot to respond to a fading cream.36

Darker skin does not rule out skin cancer. Check palms, soles and nails as well as sun exposed skin. In darker skin tones, cancer can develop where little sunlight reaches, including inside the mouth and around the genitals. Regular skin checks help detect changes early.3

Can darkening signal another health problem?

Yes. Causes include Addison disease, a hormone disorder, and hemochromatosis, which means excess iron in the body. Gradual bronzing can start at the elbows, knuckles and knees and spread. Unexplained widespread darkening should be assessed rather than assumed to be a tan.2

Dark, thick, velvety patches around the neck, armpits or groin can be acanthosis nigricans. These patches are usually harmless themselves but can accompany type 2 diabetes, hormone conditions or medication use. Rarely, they are linked to cancer. A doctor should check new patches and investigate the cause before focusing on their appearance.7

At an appointment, expect questions about when the darkening started, whether it is spreading, your medicines and other symptoms. Depending on the findings, assessment can include blood tests or a biopsy, a small skin sample examined for abnormal cells.12

What can you safely do about ordinary dark marks?

Treatment should address the cause, not just the color, even though the color is the part that gets its own product category.15

Use broad spectrum SPF 30 or higher daily. For dark marks in darker skin tones, choose water resistant tinted sunscreen with iron oxide, which also protects against visible light. Apply before going outdoors and reapply every two hours, and after swimming or sweating. Stop skincare products that burn or sting. Never apply liquid bleach. If you suspect a prescribed medicine, ask the prescriber rather than stopping it yourself.15

Once the trigger stops, marks a few shades darker than your skin usually fade within 6 to 12 months; deeper pigment can take years. Treatments can speed fading, but new marks can form. See a dermatologist if treatment is not helping.5