What Is Melasma? Causes, Triggers and Who Gets It

Melasma is a common skin condition that causes flat brown, gray-brown or bluish-gray patches, usually on the face. It happens when the cells that make pigment become overactive, and it's closely linked to sunlight, visible light, heat and hormones. It isn't dangerous, but it can be stubborn, so it helps to know what's behind it.

Below: what melasma looks like, what causes it, who's most likely to get it, and whether it goes away.

What is melasma?

Melasma is a type of hyperpigmentation: patches of skin that are darker than your natural tone because of extra melanin, the pigment that gives skin its color. Unlike a single dark spot, melasma usually shows up as larger, blotchy patches on both sides of the face. It's harmless, very common and often long-lasting.

In skin with melasma, the pigment cells (melanocytes) are more active than usual [1]. Exactly why isn't fully understood. The current thinking is that something, such as sunlight or a hormone shift, pushes those cells into overdrive, and some people are simply more likely to respond that way than others [2].

Melasma can also sit at different depths in the skin. A dermatologist may describe it as epidermal (closer to the surface), dermal (deeper) or mixed [3]. Deeper pigment tends to look more gray or bluish, and it usually takes longer to change.

You may also hear it called chloasma, especially when it appears during pregnancy (the "mask of pregnancy"). Our guide to melasma in pregnancy covers that in detail.

What does melasma look like on the face?

Melasma on the face usually looks like flat, blotchy patches with soft, irregular edges, in shades from tan to dark brown or gray-brown. It tends to appear symmetrically, on both cheeks or across the forehead, and it doesn't itch, hurt or feel raised. Many people notice it looks darker in summer and in bright daylight.

The most common places are:

• Cheeks and the tops of the cheekbones
• Forehead, often in a band across it
• Upper lip, sometimes called a "melasma mustache"
• Bridge of the nose
• Chin and jawline

Less often, it shows up on the neck, upper chest or forearms, which are all areas that get a lot of sun [1][3].

Not sure whether a patch is melasma, sun spots, freckles or marks left after breakouts? Our side-by-side guide to melasma vs sun spots vs hyperpigmentation walks through the differences.

What causes melasma?

Melasma is caused by overactive pigment cells, set off by a mix of triggers. The main ones are ultraviolet (UV) light, visible light, heat and hormones, especially estrogen and progesterone. Genetics matters too, since melasma often runs in families. Most people have more than one factor at play, which is why melasma is hard to pin on a single cause.

Sunlight: UV and visible light

UV light tells skin to make more melanin, which is why melasma favors the parts of your face that get the most sun [2]. Visible light, the light you can see, matters too. Research suggests it can cause darker, longer-lasting pigment than long-wave UVA light on medium to deep skin tones [4], which is why the American Academy of Dermatology (AAD) suggests a tinted sunscreen with iron oxides for people with melasma [5].

Heat

Many people with melasma notice their patches look darker after a hot kitchen, a sauna or a workout, even without much sun. Research suggests heat may play a role alongside light, which is one reason melasma can be so persistent in warm climates.

Hormones

Rising estrogen and progesterone, during pregnancy or while taking birth control pills or other hormone therapy, are thought to trigger melasma in some people [2][3].

Genetics

Melasma often runs in families. If a parent, sibling or other blood relative has it, you're more likely to get it too [2][3].

Other possible triggers

• Tanning beds and sunlamps
• Medicines that make skin more sensitive to sunlight, including retinoids and some antibiotics and blood pressure medicines [2]
• Thyroid problems [2]
• Stress, although the research here is mixed [2]
• Skincare that stings or burns, since irritation can make pigment darker [5]

What is hormonal melasma?

"Hormonal melasma" is an everyday way to describe melasma that appears or darkens with hormone changes, such as pregnancy, starting birth control, hormone therapy or, for some people, perimenopause [3]. It isn't a separate diagnosis, and hormones rarely act alone: sunlight usually decides how dark the patches get.

Signs your melasma may have a hormonal link:

• It first appeared during pregnancy or after you started a hormonal contraceptive
• It sits in the classic places: cheeks, forehead and upper lip
• It showed up in your 20s, 30s or 40s, when hormone shifts are common

Hormone-related melasma sometimes goes away after pregnancy or after stopping the pill that triggered it, but it can also stay for years [1]. Never stop a prescribed medicine on your own; talk to your doctor first. If you're wondering whether your pill is involved, read can birth control cause dark spots on your face.

Who is prone to melasma?

Melasma is most common in women in their 20s to 40s, in people with medium to deep skin tones, and in anyone with a family history of it. The AAD notes it's more likely in women of Latin American, Asian, Black and Native American heritage [2]. Still, melasma can happen on any skin tone, including light skin, and men get it too.

Factors that raise your chances [2][3]:

• Sex: melasma is much more common in women, likely because hormones play a role.
• Age: most people first notice it between their 20s and 40s.
• Skin tone: medium to deep skin makes more melanin in response to triggers, so patches can be more noticeable and slower to settle [1].
• Family history: a close relative with melasma raises your odds.
• Sun habits: lots of unprotected time outdoors, or living somewhere sunny and hot.

Men with melasma tend to have the same patterns and triggers as women [3]. If you're a man with blotchy patches on your cheeks or forehead, melasma is worth asking a dermatologist about.

Is melasma dangerous?

No. Melasma isn't dangerous, contagious or a type of cancer, and it isn't a sign of skin cancer [1]. It's a change in skin color. The main effect is on how people feel: melasma on the face is visible, and it can take a real toll on confidence. That's a completely valid reason to get help.

Melasma is flat and usually shows up on both sides of the face, which is one way it differs from skin cancer [1]. Still, see a dermatologist if a spot:

• appears on one side only, or looks different from your other patches
• is raised, bleeds, itches or crusts
• changes in size, shape or color

A dermatologist can often confirm melasma just by looking, sometimes with a special lamp or magnifying tool, and can rule out look-alikes [3].

Is melasma permanent?

Melasma can be temporary or long-lasting. When it's triggered by pregnancy or a medicine, it may go away on its own in the months after that trigger ends. For many people, though, it lasts for years and comes and goes with the seasons, looking darker in summer. It can also come back after it improves, especially with sun exposure [1].

How do people care for skin with melasma?

There's no quick fix, but dermatologists agree on the basics [5]:

1. Wear broad-spectrum SPF 30 or higher every day, even on cloudy days, and reapply at least every two hours when you're outside.
2. Choose a tinted sunscreen with iron oxides for protection from visible light as well as UV. Our guide to the best sunscreen for melasma explains what to look for.
3. Add shade, a wide-brimmed hat and sunglasses when you're outdoors.
4. Keep your routine gentle. Choose fragrance-free products and skip anything that stings or burns. Irritation can leave pigment behind, as we explain in 3 everyday habits making your dark marks worse.
5. Skip tanning beds and sunlamps.
6. See a board-certified dermatologist. They can confirm it's melasma and talk you through prescription options and in-office procedures if you want them.

Melasma is common, it isn't your fault, and steady sun protection is the foundation. For quick answers, browse our melasma FAQ.

References

1. American Academy of Dermatology. "Melasma: Overview." aad.org
2. American Academy of Dermatology. "Melasma: Causes." aad.org
3. Ogbechie-Godec OA, Elbuluk N. "Melasma: an up-to-date comprehensive review." Dermatology and Therapy (2017). PMC5574745
4. Mahmoud BH, Ruvolo E, Hexsel CL, et al. "Impact of long-wavelength UVA and visible light on melanocompetent skin." Journal of Investigative Dermatology (2010). PubMed 20410914
5. American Academy of Dermatology. "Melasma: Self-care." aad.org

This article is for general information and isn't medical advice. If you have a skin condition or concern, talk to a doctor or dermatologist.