The mechanism of melasma remains to be fully elucidated but current research suggests it is a multifactorial condition where pathways of pigment homeostasis are disrupted in the epidermis, extracellular matrix, and dermis.
The goal of melasma therapy is to limit the entry pathways and increase the exit pathways so that there is net loss of pigment. Once the desired amount of lightening is achieved, the next step is to find a maintenance regimen that keeps the entry and exit pathways in equilibrium. This may involve control of risk factors, topical treatments, sporadic procedural treatments, or a mixture of these techniques.
Topical therapy takes at least three months or longer to see skin lightening and those patients who are interested in a more rapid response could consider laser and light therapy.
Tranexamic acid is the most common adjunctive therapy to be used and works by decreasing melanogenesis in epidermal melanocytes and provides a rapid and sustained lightening in melasma
Laser and light therapy for the treatment of melasma is best suited for patients with refractory melasma who failed with topical treatment or a series of chemical peels. The mode-toning laser treatment is generally recommended in all skin types and its major advantage is that it destroys melanin without cell damage. Both QS low fluence and IPL are effective for recalcitrant melasma, when patients are non-responsive to other treatments, or when patients are intolerant of other treatment medications. The combination of IPL with QS laser gives a rapid resolution of mixed-type melasma with possible long-term benefits.
Fractional non-ablative lasers can be considered only if all other modalities fail. Ablative lasers should not be considered.