MELASMA ETIOLOGY AND TREATMENT: A SYSTEMATIC REVIEW

Introduction: Melasma is a common chronic refractory pigmentation disorder that predominantly affects women and individuals with darker skin types. It significantly alters quality of life and self-esteem because of its disfiguring skin appearance. Objective: to detail current information related to melasma, etiology, epidemiology, pathophysiology, histology, presentation, treatment and prognosis. Methodology: a total of 30 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 19 bibliographies were used because the other articles were not relevant to this study. The sources of information were PubMed, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: melasma, laser, pigmentation, skin. Results: Females are more affected than males in a 9:1 ratio. Melasma is infrequent prior to puberty and more common in the reproductive years. Melasma is found in 15% and 50% of pregnant women. The prevalence is 1.5% and 33% depending on the population. The most notable factor is exposure to sunlight. Next to pregnancy, direct sun exposure is the most important risk factor for melasma, shown by 27% to 51% of individuals as a trigger and 84% as a clinical deterioration factor. Approximately 83% to 93% of individuals with melasma have modifiable levels of solar elastosis. Conclusions: The treatment of melasma continues to be a challenge, because of the fact that the spots do not disappear completely in most of those affected, in addition to presenting considerable recurrence rates. The first line management is adequate sun protection and the association of sunscreens with color and topical bleaching agents, which may have a different effect on melanogenesis. In case oral medications are needed, tranexamic acid presents the best evidence for treatment. Some procedures support the treatment of melasma, such as microneedling and chemical peels that act through epidermal renewal. Lasers should be used with extreme caution because heat induces post-inflammatory melanogenesis. The combination of topical bleaching agents with medications and oral procedures provides more rapid effects, however more studies are needed regarding the treatment of the condition. KEY WORDS: melasma, laser, pigmentation, skin.