Hyperpigmentation means increased skin colour; melasma is one condition within that category. "Dark spots" describes an appearance, not a diagnosis, which is more work than a serum label usually wants to do. Finding the cause matters because treatment starts with understanding why the discoloration appeared.34
What do the different dark spots look like?
| Type | Typical appearance | Useful clue |
|---|---|---|
| Melasma | Brown patches with irregular borders, usually in a matching pattern on both sides of the face. | Often affects the cheeks, forehead, nose, upper lip or chin. |
| Postinflammatory hyperpigmentation | Marks with an irregular distribution. | Appears where there was earlier injury or inflammation. |
| Sun spots, also called solar lentigines | Distinct spots with clear borders. | Associated with accumulated sun exposure, especially in older adults. |
| Freckles | Small, numerous spots. | Typically become darker in summer. |
The pattern and history are clues, not a home diagnosis. Melasma is mostly symptom free, but itching, tingling, dryness or redness can occur. Other pigmentation disorders can resemble it, so matching facial patches alone do not settle the diagnosis.12
Why does melasma appear?
Melanocytes, the cells that make skin pigment, are more active in melasma, although exactly why is not fully understood. Sunlight is a trigger, and pregnancy related increases in estrogen and progesterone are thought to trigger melasma too. Birth control pills, some seizure medicines and medicines that increase sensitivity to sunlight can also trigger it in some people.5
Melasma is more common in women aged 20 to 40, people with medium or dark skin tones, and people with a blood relative who has melasma. It can still affect anyone. Pregnancy is one possible trigger, not a requirement for the diagnosis.56
Does the difference change treatment?
Yes. Melasma generally needs a combination of measures and ongoing protection against its triggers, rather than treatment of one isolated spot. Treatment should account for pregnancy, skin sensitivity and previous treatments. A dermatologist can select pigment reducing creams or other treatments after confirming the diagnosis.12
Sun protection is part of managing melasma:
- Use a broad spectrum SPF 50 or higher sunscreen containing iron oxides; ultraviolet and visible light both promote pigment production.
- Apply sunscreen before going outdoors and reapply at least every two hours while in the sun, including in winter.
- Wear a hat with a wide brim, limit midday sun exposure and avoid tanning beds.
Chemical peels and lasers need particular caution: they can worsen melasma or cause new pigmentation after inflammation. These procedures require expert use.13
Will melasma fade permanently?
Melasma responds slowly, especially when it has been present for a long time. Pigment near the skin surface usually responds better than pigment deeper in the skin; mixed depth melasma often improves only partly. Even after successful treatment, sun exposure can bring pigmentation back.1
Melasma often fades over several months after pregnancy ends or a triggering hormone medicine is stopped, but it can return with future pregnancies or renewed exposure to the trigger. If you suspect a prescription is involved, discuss it with the prescriber rather than changing treatment yourself.6
See a clinician if facial darkening does not go away. Diagnosis usually involves examining the skin; a Wood's lamp, a device that uses ultraviolet light, can help guide treatment. Not every dark patch is melasma: other possibilities include benign pigmented growths and skin cancers.36
Where this answer comes from
- 1Melasma (facial pigmentation)dermnetnz.org
- 2Latin American consensus on the treatment of melasmapmc.ncbi.nlm.nih.gov
- 3Pigmentation disordersdermnetnz.org
- 4Age spots and dark marksaad.org
- 5Melasma: Causesaad.org
- 6Melasma: MedlinePlus Medical Encyclopediamedlineplus.gov
