In short. Melasma is an acquired, symmetrical brown to grey-brown facial pigmentation driven by overactive melanocytes. Unlike post-inflammatory hyperpigmentation, it does not follow the site of a pimple or rash, and unlike sun spots it is not a fixed lesion but a chronic, relapsing condition. Ultraviolet and visible light are the principal triggers, with hormones second.
Key points
- Melasma is chronic and relapsing; treatment aims at lightening, not cure.
- Ultraviolet and visible light are the principal triggers; hormones are second.
- Pigment depth decides response: epidermal pigment clears better than dermal.
- Photoprotection is the foundation; nothing else works while exposure continues.
- Procedures are used cautiously because reactive melasma skin can darken.
What does melasma look like?
Melasma is an acquired hyperpigmentation that appears as symmetrical, blotchy, brown to grey-brown patches, most often on the cheeks, upper lip, forehead, and jawline. It is far more common in women, and in skin that tans easily rather than burning. It is not an infection, it is not contagious, and it is not a skin cancer.
What triggers melasma?
Ultraviolet radiation is the principal trigger, and visible light matters too, which is unusual among pigment conditions. Hormones are the second: pregnancy, hormonal contraception, and hormone replacement are all recognised triggers. That is why melasma sometimes begins in pregnancy and fades after delivery, and sometimes does not. Heat and inflammation can keep it active, so a hot kitchen, frequent saunas, or repeated harsh facial treatments may worsen it. Genes load the gun; the triggers pull it.
How is it told apart from PIH and sun spots?
| Melasma | Post-inflammatory hyperpigmentation | Solar lentigines | |
|---|---|---|---|
| Typical onset | Adulthood, often after pregnancy or a hormonal change | After acne, eczema, a bite, or a procedure | Later life, after years of sun |
| Pattern | Symmetrical patches on cheeks, upper lip, forehead, jawline | Flat marks exactly where the inflammation was | Sharply defined flat patches on sun-exposed skin |
| Behaviour | Relapses when treatment stops and exposure continues | Fades slowly once the cause settles | Persists; does not fade in winter |
| Main drivers | Ultraviolet, visible light, hormones, heat, inflammation | Inflammation or injury | Cumulative ultraviolet exposure |
| What helps | Photoprotection, topicals, cautious procedures | Control the cause, photoprotection, topicals | Photoprotection, topicals, light or laser |
| Main caution | Reactive skin can darken with aggressive treatment | Irritation can create new marks | Diagnosis before treatment |
The distinction is usually clinical. Post-inflammatory hyperpigmentation follows the map of the original inflammation, whereas melasma is symmetrical and does not. Sun spots are fixed lesions that persist once formed, whereas melasma is a relapsing condition. A dermatologist examines the distribution, the contrast against surrounding skin, and uses a specialised lamp or a dermoscope to judge how much pigment lies in the dermis. Occasionally a small sample is taken to exclude another cause, particularly when the pattern is one-sided or the patches are not symmetrical. Assessment also covers medicines, hormonal treatments, and the products already being used, because several of those actively worsen the problem.
Pigment depth decides the response
What happens in the skin is that melanocytes become overactive. They produce more melanin and pass more of it into the surrounding keratinocytes. In some people pigment also drops into the upper dermis, where it sits deeper and clears far more slowly. That depth matters a great deal: pigment in the epidermis responds better to topical treatment, while pigment in the dermis is stubborn and may never clear completely.
What does treatment involve?
Treatment is layered, and every layer is slow. Photoprotection is not optional — it is the foundation, because nothing else works while ultraviolet and visible light keep arriving. On top of that come topical agents that interrupt melanin production, used for months. Procedures such as chemical peels and light or laser treatment can be added for selected patients, but they are used cautiously: melasma skin is reactive, and an aggressive procedure can darken the patches rather than lighten them.
Expect visible change over months, not weeks.
Managed, not cured
Melasma is chronic and relapsing, with a strong tendency to return when treatment stops while exposure continues. That is not a failure of treatment; it is the nature of the condition. The realistic goal is substantial lightening sustained by a maintenance routine and strict photoprotection — not permanent disappearance, and not a single course of anything. Expect that the condition will need continued maintenance, and expect that if the routine is abandoned, it will return.
When should a dermatologist review it?
- The pigmentation is one-sided, sharply defined, or not symmetrical in the way melasma usually is.
- You are considering strong lightening creams bought online — some contain steroids or mercury and cause lasting damage.
- Patches are darkening despite treatment, or a procedure has made them worse — that needs review, not a stronger round.
Sources
- American Academy of Dermatology — melasma: overview, triggers, and treatment
- British Association of Dermatologists — melasma patient information
- Cochrane Library — reviews of treatments for melasma
Internal links
Frequently asked questions
Why do dermatologists manage melasma rather than cure it?
Melasma is chronic and relapsing, with a strong tendency to return when treatment stops while exposure continues. That is the nature of the condition rather than a failure of treatment. The realistic goal is substantial lightening sustained by maintenance and strict photoprotection.
What triggers melasma?
Ultraviolet radiation is the principal trigger and visible light matters too, which is unusual among pigment conditions. Hormones are the second, including pregnancy, hormonal contraception and hormone replacement. Heat and inflammation can keep it active, so saunas and harsh facial treatments may worsen it.
How long before melasma treatment shows a change?
Expect visible change over months, not weeks. Photoprotection is the foundation, topical agents that interrupt melanin production are used for months, and procedures are added cautiously because melasma skin is reactive and an aggressive procedure can darken patches rather than lighten them.
Risks & Limitations
- Most chronic skin disease is managed rather than cured, and relapse is expected.
- Treatments typically need 8–12 weeks before response can be judged fairly.
- Topical treatment can cause irritation, dryness, peeling and photosensitivity.
- Systemic therapy may require blood monitoring and carries organ, metabolic and pregnancy risks.
- Isotretinoin in particular requires strict monitoring and pregnancy prevention.
- Pigment change is often slow and may be incomplete.
- No treatment works for everyone, and response cannot be predicted with certainty.
When to Seek Care
- A mole or lesion that changes in size, shape or colour, or starts to bleed, itch or crust.
- Fever with a widespread rash, blistering, or rash involving the eyes, mouth or genitals — seek emergency care.
- Rapidly spreading redness, swelling or pain in the skin.
- Facial swelling or difficulty breathing — possible severe reaction; seek emergency care immediately.
- New or worsening symptoms while taking a monitored medication.
References & Further Reading
- American Academy of Dermatology (AAD) — public and clinical guidance
- World Health Organization (WHO) — skin and infectious disease resources
- Chinese Medical Association, Dermatology Branch — clinical guidance
- Cochrane Library — systematic reviews in dermatology
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.