Hyperpigmentation means the skin has produced more melanin than usual in a particular area. Melasma is one specific pattern of it: symmetrical brown patches, usually on the face, strongly influenced by sunlight and hormones. Where the extra pigment sits in the skin matters more than how dark it looks.
What is actually happening in the skin?
Melanin is manufactured in the lower part of the epidermis by cells called melanocytes. Each one serves a group of neighbouring cells, handing it to them in small packages, and those cells carry it upwards as they rise towards the surface. Melanin absorbs ultraviolet radiation, which is what it is for.
Hyperpigmentation happens when that process runs harder in a particular area, or when the colour ends up somewhere it does not usually stay. Two broad situations account for most of what people see.
In melasma, the melanocytes in affected areas are more active. Ultraviolet light drives them, hormonal changes influence them, and there is a clear inherited component: the condition runs in families and is much more frequently described in some populations than others. Visible light, not only ultraviolet, is increasingly discussed as a contributor, which is a point worth raising with a clinician.
In post-inflammatory hyperpigmentation, inflammation itself provokes melanin production. Anywhere the skin has been inflamed may be left darker afterwards: after acne, after eczema, after an injury. The distribution simply follows wherever the inflammation was, which is what distinguishes it from the symmetrical patterning of melasma.
Depth then becomes the important variable. Colour held in the epidermis sits in a layer that turns over continuously. What has dropped into the dermis, below the junction, is in tissue that does not renew in the same way, and it behaves quite differently over time.
How would a dermatologist describe it?
Melanocyte, melanin and melanogenesis cover the machinery. Hyperpigmentation is the general term; melasma and the post-inflammatory form are two specific patterns within it.
Epidermal, dermal and mixed describe where the colour sits. Clinicians make that assessment because it bears directly on what is realistic, and hearing which of the three applies to you explains a great deal about the conversation that follows.
Distribution vocabulary is used precisely for melasma. Centrofacial refers to the forehead, nose, upper lip and chin; malar refers to the cheeks; mandibular refers to the jawline. Symmetry is noted specifically, because melasma is characteristically symmetrical and many other pigmented conditions are not.
A Wood’s lamp is an ultraviolet light some clinicians use to examine pigmented areas, since the appearance under it can help indicate depth. Do not be alarmed if the room lights go off.
One further term matters. Any pigmented patch is also assessed for features that would raise a different sort of question, and a clinician looking carefully at an area of pigmentation is doing exactly what they should be doing.
What usually happens at a consultation?
The history covers when the patches appeared, whether they change with the seasons, sun exposure habits, pregnancy, hormonal contraception or hormone treatment, family history, and what has already been applied to the area. Skincare and cosmetic history is asked about in detail here, partly because some products cause irritation that leaves further pigmentation behind.
The examination assesses pattern, symmetry, borders and probable depth, possibly with the lamp described above. A clinician will also look at the affected area as a lesion in its own right, which is routine practice rather than a signal of concern.
Photographs are particularly useful with pigmentation, because change is slow and gradual, and comparing two images taken months apart is far more reliable than anybody’s impression.
What is worth asking?
Ask whether the pigmentation is thought to be epidermal, dermal or mixed. That single answer shapes what is realistic, over what timescale, and it is the piece of information most often absent from what people leave with.
Ask whether what you have is melasma or pigmentation following inflammation, since the two are frequently conflated and they behave differently. If some of both is present, which is common, knowing that prevents confusion when one part improves and the other does not.
Enquire about visible light as well as ultraviolet, if sun protection is discussed. This distinction has practical consequences and it is an area where general advice has not entirely caught up with clinical discussion.
Where treatment is raised, ask what happens if it stops, and what the expected timescale is before anything is judged. Pigmentation changes slowly, and unrealistic expectations about pace are the usual source of disappointment here.
What this page does not do
It does not tell you what the patches on your skin are, and pigmented areas are precisely the thing that warrants an examination rather than a comparison with pictures online. No product, ingredient, procedure or regimen is recommended here.
Common questions
What is the difference between melasma and the marks left by spots?
Melasma is a distinct pattern, typically symmetrical and on sun-exposed areas of the face, driven by light and hormones. Marks left after spots are post-inflammatory hyperpigmentation: pigment produced in response to inflammation, sitting wherever the inflammation was. They behave differently over time.
Why does the depth of the pigment matter?
Pigment sitting higher in the skin behaves differently from pigment that has settled deeper, in terms of how it changes over time and how it responds to anything done about it. Clinicians assess depth for that reason, and it is one of the more useful things to ask about.
Does sunlight really make melasma worse?
Sun exposure is consistently described as a major influence on melasma, and it is one of the few points on which accounts agree. That is why sun protection features so heavily in any discussion of it, and why the condition commonly fluctuates with the seasons.
Does melasma affect only women?
It is much more commonly described in women, and hormonal influences including pregnancy and hormonal contraception are recognised factors. Men do develop it, and their cases are sometimes overlooked because the association with pregnancy is so firmly established in most people's minds.
Will melasma go away by itself?
It sometimes fades substantially, particularly where a hormonal trigger such as pregnancy has passed, and it frequently varies with the seasons. It is also well known for returning. A clinician who has assessed your skin is far better placed than any page to say what is likely.
Sources
- Melasma — patient information leaflet — British Association of Dermatologists (United Kingdom) · accessed
- Sun safety and ultraviolet radiation — UK Health Security Agency (United Kingdom) · accessed
Last updated . How this page was written.