After several weeks of sun exposure, it is common to see the appearance or intensification of brown spots on the face, décolleté, shoulders, or hands. These pigment marks are often associated with photoageing and the accumulation of ultraviolet exposure over the years.
The return to work and autumn generally represent a particularly suitable period to consider their treatment, when the tan has faded and sun exposure becomes less significant.
However, a question often arises during consultations: which laser should be chosen to remove pigment spots and how many sessions should be planned?
The answer mainly depends on the nature of the pigmentation. Solar lentigines, melasma, and post-inflammatory hyperpigmentation may sometimes resemble each other, but their management is quite different.
Why do brown spots appear more frequently after summer?
Ultraviolet rays stimulate the production of melanin, the pigment responsible for skin colour.
After summer, certain areas exhibit a higher concentration of melanin, becoming visible as small brown spots of varying darkness.
Among the frequently observed pigmentations, we find:
- the solar lentigines, often referred to as "sun spots" or "age spots";
- freckles, which may darken after sun exposure;
- the melasma, often presenting as a diffuse and symmetrical pigmentation of the face;
- the post-inflammatory hyperpigmentations, appearing especially after skin inflammation.
Solar lentigines are particularly common on areas chronically exposed to the sun: face, décolleté, backs of the hands, and forearms. They correspond to benign pigmentary lesions primarily related to repeated UV exposure.
Before treating a spot: making the correct diagnosis
This is probably the most important step.
A pigment spot should not be treated with a laser simply because it is brown. Before any session, the doctor must ascertain its nature and rule out a lesion that requires specific dermatological advice.
A solar lentigo and a melasma, for example, respond differently to laser treatment.
This distinction is essential as a treatment that is too aggressive or ill-suited may, in certain situations, lead to post-inflammatory hyperpigmentation and temporarily darken the spot.
The choice of treatment also depends on the phototype, the depth of the pigment, the location of the lesions, and recent sun exposure.
For well-defined brown spots, such as certain solar lentigines, the Q-Switched pigment laser represents a particularly interesting option.
Its principle is based on the emission of extremely short pulses that target the melanin contained within the pigment lesion.
The energy delivered fragments the pigment, which will then be gradually eliminated by the body.
Available data confirms the benefit of pigment lasers in treating solar lentigines, with results achievable in a relatively limited number of sessions.
The Q-Switched pigment laser: a reference for solar lentigines
For well-defined brown spots, such as certain solar lentigines, the Q-Switched pigment laser is a particularly interesting option.
Its principle is based on the emission of extremely short pulses that target the melanin contained within the pigment lesion.
The energy delivered fragments the pigment, which will then be gradually eliminated by the body.
Available data confirms the benefit of pigment lasers in treating solar lentigines, with results achievable in a relatively limited number of sessions.
How many sessions should be planned?
In many cases, 1 to 2 sessions may be sufficient for well-defined superficial solar lentigines.
However, some more resistant pigmentations may require additional sessions.
After treatment, the spot may temporarily darken and form a thin crust. This will gradually disappear, revealing clearer skin underneath.
It is important not to pick at the crusts and to adhere to the recommendations given after the session.
Intense Pulsed Light (IPL): useful when there are multiple spots
When the face or décolleté presents with multiple small pigment spots associated with diffuse photoageing, IPL can be an excellent alternative.
Unlike a laser using a precise wavelength, IPL emits multiple wavelengths that can treat various components of photoageing.
It can act on:
- superficial brown spots;
- certain redness;
- uneven skin tone;
- the overall appearance of skin that has undergone repeated sun exposure.
We then speak more of photo-rejuvenation rather than the isolated treatment of a single spot.
The available clinical studies also demonstrate a promising efficacy of IPL on solar lentigines.
How many IPL sessions?
Generally, 2 to 4 sessions are planned, spaced several weeks apart.
The exact protocol, however, depends on the number of lesions, their intensity, the phototype, and any other associated signs of photoageing.
Q-Switched laser or IPL: how to choose?
The choice therefore does not rest solely on the colour of the spot.
For a few well-defined lentigines, the Q-Switched pigment laser allows for very targeted and often rapid treatment.
For many diffuse spots, especially when accompanied by redness or uneven skin tone, IPL may provide a more comprehensive approach to photoageing.
A recent systematic review of 41 clinical trials involving over 3,200 patients confirms the effectiveness of various laser technologies and IPL in treating solar lentigines, while highlighting that results and risks vary according to the techniques used.
And what about the Erbium YAG laser?
The Erbium YAG laser operates on a different logic.
It acts through skin resurfacing and can be of interest when other signs of skin ageing accompany pigment irregularities:
- irregular texture;
- fine lines;
- pores;
- certain scars;
- overall skin quality deterioration.
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It is therefore not necessarily the first choice for treating isolated lentigines. Its relevance increases when the aim is to achieve a more comprehensive surface skin improvement.
The number of sessions will then heavily depend on the type of resurfacing carried out and its intensity.
And Aerolase?
The Aerolase may also have its place in certain pigment management strategies, particularly when the phototype, the nature of the pigmentation, or the skin’s sensitivity necessitate a different approach.
However, it is crucial not to solely consider the machine: it is the pigment diagnosis that should determine the technology and parameters used, and not the other way around.
This notion is particularly important for medium to dark skin, which is more exposed to the risk of pigment changes following an inflammatory procedure.
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Warning: melasma is not just a simple solar lentigo
This is a fundamental point.
The melasma generally corresponds to more diffuse pigmented patches, often symmetrical, primarily located on the forehead, cheeks, upper lip, or chin.
It is influenced by several factors, including sun exposure, visible light, and certain hormonal factors.
Its treatment is complex and usually relies on a combination of photoprotection and depigmenting treatments. The use of lasers must be approached with far more caution than with a solar lentigo.
Treating melasma as a simple solar spot with an overly aggressive laser can lead to recurrence or worsening of pigmentation.
This is precisely why a prior medical consultation is essential.
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Why wait for the tan to fade?
The pigment laser targets melanin.
However, tanned skin contains more melanin in the epidermis. This melanin can also absorb some of the energy delivered by the laser, potentially increasing the risk of undesirable skin reactions.
It is therefore generally preferable to wait for the tan to completely fade before treatment.
This precaution is all the more important as post-inflammatory hyperpigmentation is one of the possible complications of pigment treatments, particularly in darker phototypes.
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How many sessions should be expected in summary?
There is no universal number of sessions, but as a guideline:
Isolated lentigines – Q-Switched pigment laser: often 1 to 2 sessions.
Multiple spots and photo-ageing – IPL: generally 2 to 4 sessions.
Erbium YAG resurfacing: protocol varies according to indication and treatment intensity.
Complex pigmentation or medium skin: personalised protocol, usually more gradual.
Melasma: specific and often combined management; laser is not always the first-line treatment.
Therefore, the number of sessions remains an estimate. It can only be precisely determined after a skin examination.
Can spots return after laser treatment?
Yes.
A laser can eliminate or significantly diminish an existing spot, but it does not remove the skin's ability to produce melanin.
New spots may therefore appear over the years, particularly with repeated sun exposure.
Rigorous photoprotection is essential after treatment and also helps limit the appearance of new lentigines.
What is ultimately the best time to treat spots?
Autumn and winter are generally the preferred times to undergo laser treatment for pigmented spots.
After summer, however, one may need to wait a few weeks for the tan to completely fade.
It is then the medical assessment that allows for the determination of:
- the exact nature of the spots;
- their depth;
- the phototype;
- the most appropriate technology;
- the anticipated number of sessions;
- the precautions to take before and after treatment.
In conclusion
There is no single “best laser” that can treat all pigmented spots.
For isolated solar lentigines, a Q-Switched pigment laser can achieve significant improvement in just a few sessions.
When there are numerous spots associated with more global photo-ageing, IPL can be particularly interesting.
The Erbium YAG laser can be considered when a more comprehensive improvement in skin texture and quality is sought.
Finally, certain pigmentations like melasma require a much more cautious and personalised approach.
After summer, the first step is therefore not to choose a laser, but to have your spots analysed in order to select the treatment suitable for your skin and type of pigmentation.
