Have you ever noticed uneven spots, acne scars or sun damage on the skin? Those are all examples of hyperpigmentation, or darkening of the skin. Hyperpigmentation can occur for a variety of reasons, including injuries and sun exposure, and while the signs can be unwelcome, there are many ways to reduce and prevent hyperpigmentation on the skin.
To understand hyperpigmentation, you have to understand what gives skin its color in the first place: melanin. Melanin is also what gives your hair and eyes their colors. Typically, the more melanin present, the darker the affected part of the body.
Melanin is a complex polymer that stems from tyrosine, an amino acid. Tyrosine is only found in the body in a special type of cell called a melanocyte. Each melanocyte contains vesicles known as melanosomes, which contain small granules of melanin. Skin gets its color when melanosomes leave the melanocytes and move into cells in the epidermis, or the outermost layer of the skin. The amount of melanin deposits, which are usually brown or black, in the epidermis determines a person's skin color.
In a person without hyperpigmentation, the skin's pigment is healthy and consistent across the body. In hyperpigmentation, certain areas of a person's skin overproduce melanin. As a result, those portions of the person's skin appear darker than his or her natural skin tone. The condition can affect any part of the skin but is most often seen on the face, hands and neck.
Hyperpigmentation is fairly common — it's one of the top reasons for seeing a dermatologist — and typically harmless. Those who have the condition most often seek treatment for cosmetic, not medical, reasons.
Causes of Hyperpigmentation
Hyperpigmentation results when one of two things happens: 1) the concentration of melanocytes, the cells that produce melanin, is unusually high, or 2) the melanocytes are abnormally active in producing melanin. The causes of hyperpigmentation include:
- UV exposure. Exposure to UV rays, from the sun in most cases, is one of the most common causes of the condition.
- Pregnancy. Women's hormones change during pregnancy, and those changes can induce abnormal melanin production. Researchers believe the elevated levels of estrogen, specifically, in pregnant women may be to blame.
- Birth control. Contraceptive medications alter a woman's levels of progesterone and estrogen to prevent pregnancy. These changes can trigger melanin overproduction.
- Heredity. Some forms of hyperpigmentation seem to run in families.
- Hormonal changes. Hyperpigmentation is more common in women than in men, with doctors pointing to women's hormonal fluctuations as the cause of that disparity.
- Heat. Even without any sun exposure, heat can trigger the skin to produce melanin.
- Certain medications. Antibiotics, antiarrhythmics, antiepileptics, and antimalarial drugs can all contribute to the condition.
- Addison's disease. With Addison's, the adrenal gland doesn't function properly. When the adrenal glands fail to produce enough cortisol, the pituitary gland responds by producing more adrenocorticotropic hormone (ACTH), which comes from proopiomelanocortin (POMC), a precursor for melanocyte stimulating hormone (MSH). In other words, the body makes more POMC to make more ACTH, and with more POMC comes more MSH, leading to darkened skin.
- Inflammation of or injury to the skin. This may include such factors as acne, psoriasis, burns, or picking at the skin.
Forms of Hyperpigmentation
Hyperpigmentation can manifest in a variety of forms, from the innocuous smattering of freckles on your nose in the summer to melasma, known as "the mask of pregnancy." Here are the most common forms of the condition:
- Lentigo/lentigenes. A form of freckle or pigmented spot, usually called a sun or age spot, that is tan, brown, or black and darker than the rest of the skin. Most commonly appear on the face and the backs of the hands and are caused by sun exposure. "Lentigenes" is the plural form of lentigo.
- Melasma. The National Institutes of Health estimate that 50-70% of pregnant women develop melasma. This form of hyperpigmentation causes a raccoon-like mask around the eyes and mouth. About 31% of women with melasma have a family history of the condition.
- Post-inflammatory hyperpigmentation (PIH). The darkening of the skin following some injury. We cover this prevalent form of hyperpigmentation in more detail in the next section.
What Is Post-Inflammatory Hyperpigmentation (PIH)?
PIH is different from traditional hyperpigmentation in that it is the body's natural response to inflammation or injury. That injury can be caused by acne, burns, psoriasis, professional skin treatments (such as chemical peels), friction, or surgery.
PIH will fade as the skin begins to regenerate, so hyperpigmentation in the epidermis often goes away in six months to a year. However, if PIH affects the dermis, the deeper layer of skin under the epidermis, the pigmentation could last for years. On the bright side, PIH usually responds quickly to treatment.
While treatment options for hyperpigmentation abound, it can take a lot of time to reduce signs of hyperpigmentation - especially severe cases. The easiest and most effective approach to the condition is simply to avoid it in the first place. Here are some preventive measures you can take to keep your skin tone even and bright:
- Avoid the sun. Try to avoid sun exposure, especially between the hours of 10 a.m. and 2 p.m. If you have to go outside, cover your head and face with a wide-brimmed hat and wear shirts with long sleeves.
- Wear sunscreen. Wearing at least SPF 30 sunscreen every day is a crucial step in preventing and treating hyperpigmentation. But one application isn't enough — you have to reapply, especially if you're sweating, exercising, or around water. Try to reapply about every two hours and look for sunscreens that protect against both UVA and UVB rays and also contain zinc oxide or titanium dioxide.
- Exfoliate regularly. Discoloration can also build up in dead skin cells on the epidermis. Exfoliating regularly will help you slough off these cells to reveal the vibrant, newer skin underneath. Depending on your skin type, aim to exfoliate one to three times per week. You can even find exfoliating scrubs that also contain a brightening agent to help with dark patches.
- Use an antioxidant or vitamin C serum. Worn daily, vitamin C serum and other antioxidants can help combat sun damage.
Whether you prefer to treat your hyperpigmentation at home or want to consult a professional, your treatment options are many. A personalized skin-care regimen can do wonders in minimizing the appearance of hyperpigmentation. Generally, products containing alpha hydroxy acids (AHAs), such as glycolic and lactic acids, can help lighten dark spots. AHAs help break up the dead skin cells stained with pigment on the epidermis. Keep in mind, though, that some skin types and medications may prevent you from using AHAs safely, so always consult your doctor first. Other treatment options include:
- Tyrosinase inhibitors. This group includes mulberry extract, kojic acid, and arbutin. The tyrosinase inhibitors block the enzyme tyrosinase, which produces melanin through the oxidation of tyrosine. Without the enzyme, melanin production drops, and hyperpigmented areas lighten.
- Intense pulsed light (IPL). Also called a photofacial, IPL treats hyperpigmentation in a 30-minute procedure that exposes the skin to intense pulses of light. The light makes blood vessels beneath the skin constrict, thereby reducing redness, fine lines, and dark spots. In some skin tones, however, IPL can make pigmentation worse.
- Exfoliation. As we mentioned earlier, exfoliation is key to treating dark spots. Exfoliating speeds up the skin cycle, and sometimes melanin production can't keep pace, so the skin lightens. Retinol is one of the most effective ingredients for exfoliation and can be found in serums and moisturizers.
- PAR2 blockers. Another powerful ingredient to look for is niacinamide, which is a PAR2 blocker. These agents prevent melanosomes, which hold melanin, from making their way into skin cells. In other words, a PAR2 blocker prevents pigment from getting into the visible layers of the skin. Keep in mind, though, that you'll have to wait for the pigmented top layer to slough off before you'll see results.
- Azelaic acid. Originally developed to treat acne, azelaic acid has recently proven effective for the treatment of hyperpigmentation. Studies have shown that is especially effective for the treatment of acne-related PIH.
Hyperpigmentation typically presents itself in a brownish-gray undertone. To neutralize that shade, look for a color-correcting foundation or concealer in a deep orange-brown color. If you're using concealer, apply it to all the affected areas after you’ve applied foundation. Start with a small amount of product and focus on blending thoroughly. If you can still see the dark spots, apply a second layer. Make sure you choose a foundation that is not too light for your skin; it will make your dark spots appear grayer. Finally, set your makeup with a powder, focusing on your problem areas.
What to Know about Corrective Cosmetic Procedures
Some more intensive procedures can benefit people with hyperpigmentation. On the other hand, some of these procedures can also make hyperpigmentation worse or even cause it in the first place. We've summarized a few cosmetic procedures below to guide you in deciding on a treatment:
- Microdermabrasion. The American Academy of Dermatology endorses microdermabrasion for only very mild cases of hyperpigmentation. Microdermabrasion treats only the most superficial layer of the skin and is thus typically ineffective for moderate to serious cases. Even for mild cases, multiple treatment sessions may be needed.
- Chemical peel. A trichloracetic acid (TCA) peel or more intensive phenol peel can also treat hyperpigmentation. When TCA is applied to the skin, the top layers of the skin dry up and peel off over the course of a few days to a week. Once the old skin is gone, you'll see a new, undamaged layer of skin. Chemical peels can be more effective at treating melasma than laser treatments.
- Fraxel pigment laser (FPL). This is a pigment-erasing laser that uses a wavelength, known as Thulium, that specifically and quickly lifts hyperpigmentation. FPL can treat melasma, PIH, sun hyperpigmentation, and acne-related pigmentation. Patients see results in about seven days, which is the treatment's primary appeal.
- Microneedling. Doctors perform this procedure with a tool called a Dermapen, which holds a group of small needles to create a controlled injury to the skin. The needling stimulates collagen production and growth factors to help the skin repair and rejuvenate itself. Usually, patients see results fairly quickly but often experience dryness and peeling in the days after the procedure.
When to See a Dermatologist
The upside to most varieties of hyperpigmentation is that they are purely aesthetic concerns — no other symptoms accompany them. This means that if you see other irregularities in your skin or are having other symptoms in addition to dark spots, something more may be going on. Either way, consulting a dermatologist is always a good idea, especially if you have other skin conditions, such as acne or psoriasis. A dermatologist can tell you the risks and benefits of treatment options in light of your skin type and medical history.
Also don't hesitate to see a doctor if you think the pigmented spot may be cancerous. A doctor can examine and biopsy the spot to make sure it is benign before proceeding with treatment. In evaluating skin spots, remember your "ABCDEs":
- Asymmetrical: not the same on both sides.
- Border: melanomas tend to have uneven borders.
- Color: a variety of colors suggests melanoma.
- Diameter: generally, melanomas tend to be larger than benign spots (larger than a pencil eraser).
- Evolving: have your doctor look at spots that change over time.
No one wants to look in the mirror and see unsightly blotches and dark spots. But, of course, you also don't want to expose your skin to harsh chemicals or treatments just for a more even skin tone. Seek effective yet gentle at-home remedies that give you the best of both worlds, lightening your skin without the added risks of more invasive options.