Discoloration

Skin discoloration is a big, blanket term for any kind of change in skin color, from a sunburn to vitiligo. Even the dark streak left from burning your forearm on the oven door is considered skin discoloration. And freckles, too. "I see skin discoloration every single day,” says Dr. William Kwan, a board-certified dermatologist and expert in skin of color in San Francisco, CA. And while most skin pigment issues are harmless, that doesn’t mean you should ignore that new spot on your arm. “One dark spot could be a melanoma for all we know,” he says. “So I would much rather see a thousand patients that come in with nothing [beyond a pigmentary issue], than to sit on something for too long.”

Some patients with skin discoloration also have psychological stressors, like self-consciousness and embarrassment, because of it.¹ Many skin discolorations, like acne hyperpigmentation (acne scars) are harmless to the body, so they don’t need to be treated—but they can be. There are several ways to treat discoloration, and while treatment can take time (weeks to months to years, depending on the deepness of the pigment), there are options worth seeking out, from lightening creams to lasers.

So yes, you should see a dermatologist if a dark spot concerns you to check it out for signs of melanoma. But even if the look of it bothers you, there’s probably something you can do about it, and that’s a valid reason for visiting a dermatologist too.

Hypopigmentation

Hypopigmentation means there’s a change in skin color to a tone lighter than the base skin color because the body isn’t producing as much melanin. Hypopigmentation could be all over the body, or in just a few spots, like a patch of skin healing from a bit of eczema. Vitiligo and albinism are examples of skin experiencing hypopigmentation; in the case of albinism, the body isn’t producing any melanin at all. Certain skin traumas—that burn from the oven door—can also cause hypopigmentation. Because hypopigmentation is usually associated with other internal medical conditions, it isn’t as common as hyperpigmentation, when the skin darkens, often because of outside injury to the skin like the sun (which has its rays set out for all of us).

Hyperpigmentation

Hyperpigmentation is when the skin darkens, and it can happen for a wide range of reasons, “typically in response to some type of injury to the skin,” says Dr. Kwan, and these are what doctors call “post-inflammatory hyperpigmentation,” he notes. “It could be inflammation like eczema. It could be an acne lesion, like a pimple. It could be a burn. It could be a scrape. Any of those things can potentially hyperpigment the skin.” Skin of color, which contains more melanin to begin with, is more likely to hyperpigment than paler skin;² and postinflammatory hyperpigmentation is one of the most common reasons patients with darker skin tones visit a dermatologist.³

Some hyperpigmentation is associated with hormonal changes—as in the case of melasma, more on that later—and other medical conditions, including cancer. But generally hyperpigmentation fades over time, from months to years. Depending on how much it bothers you, you can treat it with lightening creams and/or laser treatments, or ignore it. Always talk to your dermatologist about your options.

Melasma

Melasma is hyperpigmentation that typically shows up as brown or dark, splotchy patches on the face, cheeks, lips, forehead, and sometimes neck. It can be triggered by a hormonal change, like birth control medication, pregnancy, and hormone replacement medications—but it can be genetic, and triggered by sun and heat as well. The exact cause of melasma isn’t medically certain, but studies show that whatever the cause, it becomes worse in the sun.⁴ Melasma is common in women, but men can experience it too. “I’m one of those men that actually got it,” says Dr. Kwan. “And I probably got it from sun exposure.” He’s had patients who had melasma flare after spending time in a sauna, or after doing Bikram yoga, and even a baker who spends their days in front of a hot oven.

While pregnancy-related melasma typically ends after giving birth, for others, melasma can be a lifelong condition. And because melasma is so tied up with sun exposure, treating it calls for a lifestyle change: “I tell my melasma patients, ‘if you truly want to get your melasma under control, you really have to think of those places where you might be getting sun or exposure to heat.’”—and avoid them—says Dr. Kwan. That might mean wearing a floppy hat and sun-protective clothing at the beach, or canceling the Bikram membership. “Usually, melasma is chronic,” he adds, “and patients are constantly treating it whenever it flares.”

Other treatments, like lightening creams, intense pulsed light, and various laser treatments, can lighten areas of melasma, but these don’t “cure” it completely, and some patients report their melasma returning.5

Melasma is also called “the mask of pregnancy” and is the same thing as “chloasma,” but doctors use the term melasma more often.

Chloasma

Chloasma is lesser-used term for melasma; technically, they’re the same thing.

Acanthosis Nigricans

Acanthosis nigricans is a skin condition in which the skin darkens and takes on a velvety texture in folds and creases of skin, usually in the neck, arm, and groin area. It’s often associated with obesity, diabetes, or weight gain, but it might present in patients with cancer, or as a reaction to certain medications. “It’s not necessarily hyperpigmentation,” notes Dr. Kwan, “It’s actually a velvety texture to the skin that does look darker, but it’s more involved than just pigmentation. There are epidermal changes.” Acanthosis nigricans isn’t harmful, but it could be a sign of a yet-undiagnosed condition like diabetes, so it’s important to have it checked out by your doctor.