In short. Why melasma is treated with repeated gentle passes rather than one aggressive treatment, and what the course actually involves over its length.
Key points
- An assessment that establishes the pigment is melasma and that the skin is in a state to be treated.
- A test spot, watched for a period before the face is treated.
- A series of short sessions spaced apart, at settings chosen for this skin rather than for the device's capability.
Low-energy laser treatment for melasma looks undramatic next to laser treatment for other pigment problems, and that is deliberate. The rationale is worth understanding, because a patient who expects a visible single-session result will misread a correctly planned course as a failure.
Why the passes are gentle and repeated
In most pigment treatment, more energy clears more pigment. In melasma that relationship breaks down, because the pigment cells in the affected area respond to inflammation by producing more pigment. Energy delivered into the skin creates heat, heat creates inflammation, and inflammation is the trigger. The clinical answer is to stay below the threshold at which the skin reacts, which means lower energy and repeated short sessions rather than one aggressive pass.
Each session produces a partial change. The pigment that has been broken up is cleared gradually, and the skin is given an interval in which to settle before the next session. Over a course the area typically lightens, and the lightening is judged at the end of the course rather than after each appointment.
What the course involves
An assessment that establishes the pigment is melasma and that the skin is in a state to be treated. A test spot, watched for a period before the face is treated. A series of short sessions spaced apart, at settings chosen for this skin rather than for the device's capability. A review of what the skin has done between sessions, and a defined point at which the course ends.
What the skin does between sessions
Redness for a day or two after a session is expected, and pigment may darken slightly before it fades. Between sessions the skin should return to its baseline. If it does not, if it stays red, stings, or continues to feel reactive, that is information about the settings rather than a normal part of the course, and it is a reason to review the plan rather than to continue it. Skin that is still settling is not skin that should be treated again.
What a course of sessions will not deliver
- A single-session result. The course is designed around partial changes accumulating.
- A permanent clearing. Melasma recurs, and the course is followed by maintenance.
- Control of the condition. Daily protection and topical treatment are what hold the result.
It is also worth understanding what the low-energy approach asks of the patient, because the cost of a course is measured in appointments as well as in money. Short, spaced sessions mean a longer calendar commitment than a single treatment would, and the lightening appears gradually rather than after one appointment. Patients who accept that framing usually find the course easier to persist with than those who are waiting for a single visible change.
Ask what the settings are chosen for, what the skin is expected to do between sessions, and what would cause the course to stop. Those three answers separate a planned course from a series of appointments.
Frequently asked questions
Why is the energy kept low if the pigment is stubborn?
Because the pigment reacts to inflammation more than it reacts to energy. Delivering more energy clears more pigment in the short term and creates more inflammation, and in melasma-prone skin that inflammation drives further pigment production. Low-energy passes repeated across sessions reduce the pigment gradually while keeping the skin below the threshold that provokes it.
How many sessions are involved?
More than most patients expect, and the number is decided as the course proceeds rather than fixed at the outset. Sessions are spaced so the skin settles between them, and the plan is reviewed against what the skin has actually done. A clinic that quotes a fixed number before treating a test area is quoting a package rather than a plan.
What does a session feel like?
Brief snapping sensations as the pulses are delivered, usually described as tolerable without anaesthesia. A cool pack is often used. The skin is pink to red afterwards for a day or two, feels warm and tight, and may be mildly swollen. Pigment that has been broken up can darken slightly before it fades over the following days.
Risks & Limitations
- Rebound darkening. Melasma-prone skin produces more pigment in response to inflammation, and both a laser and a peel create inflammation deliberately.
- Blistering, crusting or a burn if the settings or the contact time do not match the skin, with a small risk of scarring.
- Post-inflammatory pigment change in either direction, darker in most cases and lighter in some.
- Infection in skin that has been broken, and uneven peeling after a chemical agent.
- An allergic reaction to the peeling agent, which is a reason a test spot comes first.
- Increased sun sensitivity after either route, while the skin is settling and afterwards.
- Melasma is a tendency, not a lesion. Neither route removes it, both are followed by maintenance, and the pigment usually returns.
- No outcome is guaranteed, and individual response varies with the depth of the pigment, the skin type and how consistently the skin is protected.
When to Seek Care
- Blistering, crusting or a burn in the treated area — contact the treating team the same day.
- The treated area becoming darker rather than lighter after a session has settled.
- Spreading redness, swelling, pain or discharge, or a fever.
- Skin that stays red, stings or feels reactive between sessions rather than returning to normal.
- A dark patch that is new, changing in size, shape or colour, bleeding or failing to heal — seek assessment rather than treatment.
- Difficulty breathing, or swelling of the lips, tongue or throat after a chemical peel — seek emergency care immediately.
References & Further Reading
- American Academy of Dermatology Association (AAD) — patient information on melasma and pigmentary disorders
- British Association of Dermatologists (BAD) — guidance on laser and light therapy and on chemical peels
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance on skin lesions and referral
- Cochrane Library — systematic reviews in the treatment of melasma
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.