Melasma appears as flat patches of light brown, dark brown, or blue-gray discoloration on the skin, most often on the face. The patches are typically symmetrical, meaning they show up in matching locations on both sides. Unlike a single freckle or sun spot, melasma tends to cover larger areas and often looks like a mask or map-like pattern across the cheeks, forehead, nose, or upper lip.
Colors and Border Patterns
The exact color and edge definition of melasma depend on how deep the excess pigment sits in your skin. There are three recognized types, and each looks noticeably different.
Epidermal melasma involves pigment in the outermost layer of skin. It appears dark brown with well-defined, relatively sharp borders. The color tends to be uniform across the patch.
Dermal melasma sits deeper. The patches look light brown, bluish-gray, or grayish-brown, and the borders are blurry or feathered rather than crisp. This type is harder to treat precisely because the pigment is further from the surface.
Mixed melasma is the most common and combines both depths. You’ll see a patchwork of brown and blue-gray tones, sometimes with sharper edges in some spots and softer ones in others. Most people with melasma have this mixed presentation.
Where It Shows Up on the Face
Melasma follows three characteristic distribution patterns on the face, and the pattern you have is one of the first things a dermatologist will note.
- Centrofacial: The most common pattern, covering the forehead, cheeks, nose, upper lip, and chin. This is what people typically mean by the “mask” appearance.
- Malar: Limited to the cheeks and nose, sparing the forehead and lip area.
- Mandibular: Appears along the jawline. This pattern is less common and sometimes overlooked because people don’t associate the jaw with melasma.
In some cases, melasma also develops on the neck, arms, or chest, though facial patches are by far the most typical. The patches are always flat. If a dark spot is raised, bumpy, or has an irregular texture, it’s something else.
How It Differs From Sun Spots and Other Dark Patches
Several types of hyperpigmentation can look similar at a glance, but the differences are straightforward once you know what to look for.
Sun spots (solar lentigines) are smaller, individual flat brown spots that appear on areas with heavy cumulative sun exposure: the face, chest, shoulders, and hands. They don’t form the large, symmetrical patches that melasma does, and they don’t fluctuate with hormonal changes.
Post-inflammatory hyperpigmentation (PIH) is darkening that follows skin injury or inflammation, like acne, eczema, or a bug bite. The key distinction is location: PIH shows up exactly where the inflammation was, so the patches aren’t symmetrical and they don’t follow melasma’s predictable facial patterns. A dark mark left behind after a pimple on one cheek, for instance, is PIH, not melasma.
Melasma’s symmetry is its signature. If you notice matching brown or grayish patches on both cheeks, or a band of discoloration stretching across your forehead that mirrors itself, that bilateral pattern is the visual hallmark that separates melasma from other causes of dark spots.
The “Mask of Pregnancy”
Melasma is sometimes called chloasma or the “mask of pregnancy” because it frequently appears during pregnancy, when rising levels of estrogen, progesterone, and melanocyte-stimulating hormone trigger excess pigment production. This hormonal connection is why melasma is far more common in women than men. Birth control pills and hormone replacement therapy can trigger it for the same reason.
Pregnancy-related melasma most often appears during the third trimester and typically affects the cheeks, forehead, chin, nose, and the area above the upper lip. In some women, it fades after childbirth. In others, it persists for years or becomes a lifelong condition that waxes and wanes with sun exposure and hormonal shifts. There’s no reliable way to predict which outcome you’ll have.
What Makes It Look Worse or Better
One of the most distinctive things about melasma is that it changes with the seasons and with sun exposure. Patches often darken noticeably in summer and lighten somewhat in winter. Even brief, unprotected sun exposure can intensify existing patches within days. This fluctuation is a useful clue: sun spots and PIH don’t respond to sunlight as quickly or dramatically.
Heat can also darken melasma independent of UV light. Some people notice their patches deepen after cooking over a hot stove, sitting near a fire, or spending time in a sauna. Visible light from screens and indoor lighting may contribute as well, though to a lesser degree than direct sunlight.
Because of this sensitivity, the appearance of melasma on any given day isn’t fixed. You might notice your patches are barely visible in January and strikingly obvious by July. This doesn’t mean the condition is getting worse overall; it means the underlying pigment cells are reactive to environmental triggers.
What a Dermatologist Looks For
Melasma is usually diagnosed visually based on its characteristic color, symmetry, and location. When there’s any uncertainty, a dermatologist may use a Wood’s lamp, which emits ultraviolet light to reveal how deep the pigment sits. Under this light, epidermal melasma appears as sharply defined brown or black patches because the UV highlights superficial pigment. Dermal melasma looks like unaccentuated gray-blue areas because the deeper pigment doesn’t fluoresce the same way. This distinction matters because superficial melasma generally responds better to topical treatments, while deeper pigment is more stubborn.
No biopsy is typically needed. If a dark patch has irregular borders that aren’t symmetrical on the face, is changing rapidly in shape, or has multiple colors including red or black, those features point away from melasma and warrant closer evaluation for other conditions.