Unmasking the causes and treatments of melasma

This challenging skin condition causes dark patches on the skin that can last for years.

By October, your summer tan is probably almost gone, but a glance in the mirror may still show some darkened patches on your skin that seem to be sticking around. These brown or grayish-brown blotches, typically on the forehead, chin, cheeks, upper lip, or nose, may signal a condition called melasma.

Melasma is sometimes referred to as the mask of pregnancy, because it is sometimes triggered by an increase in hormones in pregnant women. But while the condition may be common among pregnant women, it isn't limited to them.

"It's not only associated with pregnancy, but can affect women at all stages of life," says Dr. Shadi Kourosh, director of the Pigmentary Disorder and Multi-Ethnic Skin Clinic at Harvard-affiliated Massachusetts General Hospital. And it may last for many years. "Women who develop melasma in their teens or 20s or 30s may see it stay around for decades," says Dr. Barbara Gilchrest, senior lecturer on dermatology at Harvard Medical School.

A persistent and vexing condition

While melasma isn't painful and doesn't present any health risks, it can cause significant emotional distress for the estimated six million American women who develop these dark patches on their faces. The condition can be difficult to treat, and there's a lot of misinformation out there about what causes it, says Dr. Kourosh.

You're more likely to get melasma if you have a darker skin type, probably because your skin naturally has more active pigment-producing cells, according to the American Academy of Dermatology. Melasma appears when these cells become hyperactive and produce too much pigment in certain areas of the skin. The mechanism is similar to what causes brown age spots and freckles, but melasma patches tend to be larger.

Melasma is more common in women, but it can also affect men. It may have a genetic component, as it often runs in families.

Melasma has a lot of different causes, says Dr. Kourosh. Two in particular stand out:

Hormones (including hormonal medications). Fluctuations in certain hormones can cause melasma, which is why it commonly occurs during pregnancy. Melasma may also occur when you either start or stop hormonal contraception, including birth control pills, or when you take hormone replacement therapy, says Dr. Gilchrest.

Sun exposure. The sun is the big culprit in triggering melasma. "Underlying factors such as hormonal changes may not manifest until a person goes on vacation to a southern location like Florida, or during the summertime when she spends more time in the sun," says Dr. Kourosh. "The sun is the major exacerbating factor, whatever the underlying cause." Melasma can be caused or worsened by not only the sun's rays, but also heat and visible light. This means that even sunscreens that protect against skin cancer aren't enough to ward off melasma, says Dr. Kourosh. This makes treating melasma a challenge, particularly in the summer months.

Treating melasma

The first step in treating melasma is confirming with a dermatologist that your darkened skin patches are indeed melasma, and determining what's causing it. Treating melasma is unlikely to be effective if the underlying cause isn't addressed, says Dr. Kourosh. "Even the oral treatments that now exist for severe cases of melasma are really pointless to do if there are still triggers in place," she says. If you're still being exposed to exacerbating factors, you could just be on a hamster wheel, running and not getting better.

"We take a thorough medical history to find out what's causing the melasma," says Dr. Kourosh. Then adjustments are made. If a hormonal contraceptive is causing the problem, a woman might consider switching to a nonhormonal option, such as a copper intrauterine device.

Shun the sun

The next step in treating melasma is to prevent the sun from aggravating the condition. This may require extreme diligence. "The sun is stronger than any medicine I can give you," says Dr. Kourosh. The most important way to clear up melasma is by using a strict sunscreen regimen. But keep in mind that not all sunscreens are created equal. To prevent against melasma, you need a sunscreen that blocks not only the sun's rays, but also its light and heat.

There are two main types of sunscreens:

• sunscreens that use chemicals, such as oxybenzone

• sunscreens that use physical blockers, such as zinc and titanium dioxide.

"You want to choose the non-chemical, blocking sunscreen, because that will stop all the light and different wavelengths from coming through," says Dr. Kourosh. Luckily, these sunscreens have come a long way from older formulations that sat on your skin in a greasy, white layer. Today's zinc and titanium dioxide formulas are micronized so they can sink into the skin, while still offering the same protection. You can buy them at your doctor's office, skin care stores, or even the drugstore. "I'm not loyal to any specific brand," says Dr. Kourosh.

Chemical sunscreens don't offer the same protection for melasma, and in some instances, they may even trigger allergic reactions that can make melasma worse, she says.

You can provide added protection to your skin by following up with makeup that contains a second sunscreen to further block out the sun's rays. Even in the fall and winter it's a good idea to wear a hat that is designed to provide sun protection, if you're going to be outside for an extended period of time.

Medications and topical treatments

Your dermatologist may prescribe medications or topical treatments to help lighten melasma. Some commonly used options are topical retinols and retinoid treatments, which are applied to the skin to help speed your body's natural cell turnover process. This may help dark patches clear more quickly than they would on their own.

In addition, some doctors may prescribe bleaching agents, such as hydroquinone, which works by blocking melanin production. But while products with hydroquinone can be purchased over the counter, they should only be used under a doctor's care — and only on the darkened areas of the skin.

"Higher concentrations of hydroquinone can cause white spots to develop on the skin," says Dr. Gilchrest. The medication may even cause a darkening of the skin in some cases.

Your dermatologist might also recommend kojic acid or azelaic acid, which are other topical skin lightening agents, she says.

Other treatments that are sometimes recommended for melasma include chemical peels, laser treatments, and skin microneedling. But at this point they're not reliably effective, says Dr. Gilchrest.

For example, peels can work for some people. "And for some people it makes it worse. It's very hard to predict," says Dr. Gilchrest.

At-home treatments

There's more you can do on your own to help your skin heal and prevent future damage. In addition to reducing sun exposure, try these steps:

Establish a good cleansing regimen. Environmental pollution can contribute to melasma, says Dr. Kourosh. Airborne pollutants can bind to the skin and corrode the protective surface, making it weaker and more susceptible to sun damage. Clean your skin every night before bed with a cleanser that can thoroughly remove particulate matter and help protect the skin, she says.

Combat skin stress with antioxidants. Vitamins C and E can help heal damage from sunlight. So, dab on a few drops of a serum that contains these vitamins to improve skin health and ward off the harmful effects of sun exposure.

Moisturize your skin regularly. Use a good moisturizer after the serum to restore the lipid (fat) barrier of the skin, which helps to protect it from damage.

Be patient. Even with treatment, it may take months for melasma to clear up. There's no overnight fix.

Be diligent. Melasma will be quick to return if you're not careful about sun protection. So, long-term maintenance requires an ongoing commitment to protecting your skin.

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