"Damage due to inflammation, UV exposure, and other environmental insults causes the cells to produce more pigment to protect themselves," says Carl R. Thornfeldt, MD, a dermatologist in Fruitland, ID. Changes in estrogen levels (due to birth control pills or pregnancy) can also play a role.
This results in uneven pigmentation, a common condition that can affect any skin tone, "but in different ways," says Elizabeth Tanzi, MD, assistant clinical professor of dermatology at George Washington University. Lighter skin tones tend to develop freckles and sun spots, while darker skin looks shadowed or patchy, she says.
Since the causes of uneven pigmentation are so common -- and the demand to correct the condition is so high -- many options exist for treating brown spots and patches. But you can't treat all spots equally. Before you pick a course of action, see your dermatologist, Tanzi says. Ingredients can be harsh and irritating, so get advice about which to use and how to safely use them the right way.
One option is hydroquinone, a prescription topical cream that slows down the pigment-making processes in the skin, Tanzi says. "Hydroquinone is one of the strongest and most effective brightening agents we have," she says. But at high concentrations it can be toxic to the skin, she says. (Some countries have banned it. In the U.S., most doctors think a low dose is safe, but they closely watch their patients.)
Doctors usually prescribe a 4% hydroquinone cream, and a 2% version is available over the counter. "Hydroquinone can be irritating and can actually increase pigmentation if used for too long, so I have patients take a ‘holiday' every 3 months and use other lightening agents," Tanzi says. Your doctor may suggest alternating hydroquinone with over-the-counter (OTC) treatments to limit irritation and avoid an adverse reaction.
Retin-A (tretinoin) and steroids may be prescribed in addition to or in place of hydroquinone, but they might not work as well, says William Rietkerk, MD, an associate professor of dermatology at New York Medical College.
That's why he says he suggests his patients try OTC options rather than hydroquinone. "The non-prescription products don't have the same risk of complications and are still effective at reducing pigmentation." One of the best is kojic acid, Rietkerk says. "It is a very effective pigment reducer that you can use continuously without the risk of the side effects that can come with hydroquinone."
Vitamin C is another popular treatment. Studies show C can help brighten skin and fade hyperpigmentation much like hydroquinone, but without as much irritation. "Look for high levels of magnesium ascorbyl phosphate in the ingredients of a brightening treatment," says Renée Rouleau, a Dallas-based aesthetician who treats hyperpigmentation. This form of vitamin C stays stable, so it's more effective.
Other OTC options that may help include soy, niacinamide, ellagic acid, arbutin, and licorice, according to some research results. Your doctor may combine one of these treatments with hydroquinone to minimize reactions and irritation.
"Most people forget that uneven pigmentation doesn't have a quick fix," Thornfeldt says. "The damage occurs deep in the skin and takes time to come to the surface, which means reversing the damage can also take time." That's why the most effective treatment for uneven skin tone might be patience.
Hyperpigmentation doesn't happen overnight -- it's the result of sun damage over time, Tanzi says. Here's what she suggests doing to avoid it.
Seek shade. "I always talk to my patients about avoiding the sun," she says. Whenever possible, stand in a spot out of direct sunlight -- even little things, like crossing to a shadier side of the street, matter.
Never skip SPF. "You have to wear an SPF 30 sunscreen every day," Tanzi says. Every UV ray that hits your skin causes damage, she says. And the damaging rays can pierce through clouds and glass, so you always need SPF protection.
Wear a hat. A wide-brimmed hat will shield your face, the area most prone to hyperpigmentation, Tanzi says. You need that physical protection from the sun. And a hat is a key accessory if you're undergoing treatment for hyperpigmentation.
"You have to wear a hat every day; otherwise, a topical cream won't do anything," she says.
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