Laser treatment removes moles and other skin lesions permanently as long as the skin lesion is selected carefully and the treatment course is adequate. This often means that multiple treatments are required.
Removing moles with a laser should be permanent, as long as:
- the mole or skin lesion to be removed is well-suited to laser treatment
- the treatment course is adequate, i.e. correct wavelength, pulse duration and energy intensity settings at the time of treatment, and a sufficient number of treatments
- the treated area is properly cared for by the patient (i.e. avoiding sun exposure after treatment)
Some moles or skin lesions are to deep to completely remove because laser may not penetrate to a sufficient depth. In these cases, laser treatment may work effectively on the upper levels of the mole, casing it to fade initially. However, if the laser has not penetrated to the deepest levels of the mole, the pigment-producing cells can regenerate, causing recurrence of the mole. Because it can be difficult to assess the depth of a mole by examining it, sometimes laser treatment is attempted but the result isn't permanent.
It's important to bear in mind that even when laser mole removal is permanent, it might not be appropriate. Moles that resemble melanomas must never be treated by laser due to the risk of accidentally concealing an incompletely-treated melanoma. In some cases, people at high risk (e.g. with many moles) may consider preventing melanoma through mole removal. Laser treatment of moles in these people may appear effective but there's no evidence that removing normal moles reduces the risk of later melanoma. Such treatment would probably be expensive, since Medicare and private health insurance would probably not cover mole removal in these circumstances.
Permanent removal b y laser is most likely for pigmented lesions that are flat and very shallow, particularly age spots, freckles, lentigines, angiomas or telangiectasia. These usually disappear permanently with adequate laser treatment, but because they are caused by increasing age and sun exposure, new ones commonly appear even after laser treatment. this means that while laser treatment is highly effective for the treatment of skin lesions on sun-damaged skin, the treatment effects aren't permanent and repeat treatments may be required to maintain the cosmetic effect in future years.