In short. Brown is not one condition. Sun-driven marks, melasma and marks left by inflammation look similar and behave differently, and the history tells them apart.
Key points
- Note where it sits and whether it is symmetric; whether the edges are sharp or soft; whether it appeared with a pregnancy, a change in contraception, a new medicine or a period of sun; and whether it is stable, fading or spreading.
- Those five answers do more of the diagnostic work than a photograph, and they take a few minutes to write down before an appointment.
Almost everyone who describes their skin as uneven is looking at brown, and brown is not one condition. The three commonest patterns differ in where they sit, what drives them, and how they respond to treatment. Two of them are made worse by being treated as though they were the third.
Sun-driven pigment
Cumulative ultraviolet exposure over years produces flat brown marks on the areas that face the light: the cheekbones, the temples, the sides of the forehead, the upper lip, the backs of the hands. They have relatively defined edges, deepen after a sunny holiday and lighten over the winter. This is the pattern that responds most predictably to treatment, and the one that keeps returning, because the exposure that produced it has not stopped.
Melasma
Melasma is symmetric, softly edged and brown to grey-brown, sitting across the cheeks, upper lip, forehead or jaw. It is driven by hormonal change, by ultraviolet and visible light, and by heat, and it is chronic and relapsing. Pregnancy and hormonal contraception are common triggers. It behaves differently from sun-driven pigment in one important respect: the melanocytes involved are already overactive, so anything that inflames or heats the skin can push them further in the wrong direction. Melasma is therefore treated slowly and gently, and clearing it is not the goal.
Marks left by inflammation
A healed acne lesion, an insect bite, a burn, a scratch or an earlier procedure can leave a flat brown mark exactly where the skin was injured. These fade by themselves over months and sometimes years. Skin that marks easily after a spot is skin that will also mark after aggressive treatment, which is why the useful response is to stop creating more inflammation. Picking, scrubbing and repeated acid use all prolong them.
How to describe your own pattern usefully
Note where it sits and whether it is symmetric; whether the edges are sharp or soft; whether it appeared with a pregnancy, a change in contraception, a new medicine or a period of sun; and whether it is stable, fading or spreading. Those five answers do more of the diagnostic work than a photograph, and they take a few minutes to write down before an appointment.
Why the difference matters
Sun-driven pigment and post-inflammatory marks both sit relatively high in the skin and both improve with time and topical treatment, though by different mechanisms. Melasma may sit at several depths at once, and it is the pattern where an aggressive approach is more likely to worsen the appearance than to improve it. Nothing about the colour of a patch in a photograph separates these reliably; the history and an examination do.
Three things that make any pigment pattern worse
- Further unprotected sun exposure, which creates new marks and darkens the existing ones.
- Irritation from over-cleansing, scrubbing or too many active products at once.
- Picking or squeezing a healing spot, which converts a temporary mark into a longer one.
Frequently asked questions
Does the position of the brown patches tell you which pattern it is?
It narrows it considerably. Marks sitting only on the areas that face the light, with fairly defined edges and a summer-winter swing, suggest cumulative sun exposure. A symmetric pattern across the cheeks, upper lip and forehead with soft edges suggests melasma. Marks sitting exactly where a spot or an injury healed suggest post-inflammatory pigment, whatever their colour.
Why do some brown marks fade on their own while others do not?
It depends on where the pigment sits and whether the process producing it has stopped. Marks left by inflammation sit relatively high in the skin and are cleared gradually once the inflammation has settled. Sun-driven pigment fades only when new exposure stops adding to it. Pigment held deeper in the dermis is largely beyond what the skin clears by itself, and it is also the least responsive to treatment.
Is melasma simply a more stubborn form of sun damage?
No, and the difference changes the plan. Sun-driven pigment is a record of exposure, so protecting the skin stops it accumulating. Melasma is an active process influenced by hormones, visible light and heat, and it relapses even when exposure is well controlled. Treating it as stubborn sun damage is exactly how people end up with darker skin than they started with.
Risks & Limitations
- Uneven tone is not one condition. Pigment, vessels and texture answer to different treatment, and a plan built on the wrong category can produce no change however long it is continued.
- Pigment that has faded returns with further unprotected sun exposure, and melasma relapses when control lapses. Maintenance is part of the result rather than evidence that treatment failed.
- Melasma is the pattern where aggressive treatment can leave skin darker rather than lighter; rebound darkening after high-energy pigment work is a recognised outcome, not a rare accident.
- No treatment resets skin to a single uniform colour. Tone can be reduced and evened, and pigment held deep in the dermis responds poorly to everything available.
When to Seek Care
- A mole or spot that is changing in size, shape or colour, or that itches, bleeds or fails to heal — have it examined rather than lightened.
- Darkening that has developed over weeks rather than years, or that appeared away from skin exposed to the sun — seek medical assessment.
- Darkening with tiredness, weight change, cold intolerance or dizziness, which may point to a hormonal or metabolic cause.
- Darkening with yellowing of the eyes or skin, dark urine or pale stools — seek medical assessment promptly.
References & Further Reading
- American Academy of Dermatology (AAD) — patient guidance on pigmentation disorders
- International League of Dermatological Societies (ILDS) — global standards of care
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance
- Cochrane Library — systematic reviews
- Chinese Medical Association Dermatology Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.