In short. Which pigment problems a picosecond laser suits, which ones need a diagnosis before any device is chosen, and the situations in which you are not a candidate yet.
Key points
- A patch of brown is a description, not a diagnosis.
- Two people with identical-looking pigment can need opposite advice, because one has surface pigment that clears and the other has a reactive condition that repeated treatment can make worse.
- If nobody has told you which one you have, that question comes first.
A picosecond laser is a pigment tool. That single fact decides most of the candidacy question, because it means the treatment is a good answer only when the problem is pigment, and only when someone has established what kind of pigment it is. Most disappointments in this field begin with a device being booked before the diagnosis was made.
What the diagnosis changes
Brown marks on a face are not one condition. Freckles and sun spots sit in the surface layer and often respond well to a series. Pigment held deeper in the skin shifts more slowly and rarely clears completely. Melasma-type pigment is a reactive condition rather than a set of spots, and it is the least predictable and the most easily worsened. A mole, or any lesion that has changed, needs a dermatological examination rather than a laser.
That is why a proper assessment comes before any quotation. The clinician looks at the pigment in ordinary light and with a lens, asks how long it has been there, whether it changes with sun and season, whether it appeared during pregnancy or while taking hormonal medication, and whether your skin darkens after injuries or earlier treatments. Those answers predict the outcome far better than anything about the device.
Diagnosis before device
A patch of brown is a description, not a diagnosis. Two people with identical-looking pigment can need opposite advice, because one has surface pigment that clears and the other has a reactive condition that repeated treatment can make worse. If nobody has told you which one you have, that question comes first.
Who tends to do well
Good candidates usually have discrete, stable pigment, skin that has not seen recent sun, no active infection or broken skin in the area, and a realistic expectation of improvement across a series rather than removal in one appointment. They accept that the mark may not disappear completely, and they are willing to protect the skin from sun for months afterwards.
Poor candidates are not unhealthy people. They are people with an unclear diagnosis, people whose pigment is still settling on its own, people with melasma-type pigment expecting clearance, people who cannot avoid sun in the weeks after treatment, and anyone whose expectation is that the mark disappears completely and stays gone.
Reasons to wait or refuse
- A lesion that is new, changing in shape or colour, itching or bleeding — that needs a dermatology examination first, and a laser is the wrong next step.
- Recent sun exposure or an active tan, which raises the chance of the treatment itself causing darkening.
- Pigment that is still fading on its own after acne, a burn or another procedure — waiting costs nothing and often resolves it.
The useful question is not whether a picosecond laser can treat pigment, because sometimes it can and sometimes it should not. The useful question is what your particular brown mark is, and whether anyone has looked at it closely enough to answer that. Until someone has, candidacy is simply unknown.
Frequently asked questions
How do I know whether my brown patch is the kind that responds?
Nobody can tell from a description. Surface pigment such as freckling and sun spots tends to respond, pigment held deeper shifts slowly and often only partly, and melasma-type pigment is the least predictable of all. The answer comes from an examination, not from a photograph or a questionnaire.
What is the difference between surface pigment and deeper pigment?
Where the pigment sits in the skin decides how it behaves. Pigment in the surface layer is closer to the treatment and tends to clear more readily and more completely. Pigment held deeper shifts gradually across a series and often lightens rather than disappears. The distinction is made by looking at the skin properly.
Should I have treatment if my pigment is still fading on its own?
Usually not. Marks that appeared after acne, a burn or another procedure often settle over months without help, and treating them adds the risk of darkening without adding speed. Waiting is a real option and it costs nothing.
Risks & Limitations
- Post-inflammatory hyperpigmentation — the treated area becoming darker than it was — is the most common unwanted outcome. It is more likely in darker skin, after recent sun exposure and when sessions are spaced too closely together.
- Hypopigmentation, where treated skin becomes paler than its surroundings, is less common than darkening and can be long-lasting.
- Scarring is uncommon but real, and more likely when skin is treated aggressively or repeatedly.
- Blistering, infection and reactivation of cold sores occur occasionally.
- Melasma-type pigment can become more reactive with repeated treatment and may worsen rather than improve.
- Results are incremental, usually need several sessions, and are not permanent. Pigment often returns over months and years.
- A pigmented lesion that is new or changing should be examined rather than treated, and no cosmetic treatment should delay that assessment.
When to Seek Care
- Blistering, weeping or broken skin beyond the expected reaction.
- Spreading redness, warmth, pus or fever.
- Pain that is worsening rather than settling after the first day.
- Treated skin that becomes paler than its surroundings, or that keeps darkening week after week.
- A new, changing, itching or bleeding lesion, whether or not it has been treated.
References & Further Reading
- American Academy of Dermatology (AAD) — pigment, laser and tattoo removal information
- American Society for Laser Medicine & Surgery (ASLMS)
- National Medical Products Administration (NMPA, China) — device registration status
- Cochrane Library — systematic reviews in laser dermatology and pigmentation
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.