Topical Treatments for Melasma: A Systematic Review of Randomized Controlled Trials

Background: Melasma is an acquired skin disease characterized by symmetric hyperpigmentation on sun-exposed areas, particularly on the face. Recently, there has been tremendous scientific interest in novel, safe, and effective topical agents to manage melasma. Objective: To evaluate topical treatments for melasma and provide evidence-based recommendations for clinical use and further research. Methods: We performed a systematic review of randomized controlled trials (RCTs) on topical agents for the treatment of melasma on March 4th, 2019 using PRISMA guidelines. Clinical recommendations were based on the American College of Physicians guidelines. Results: After screening, we identified 35 original RCTs using azelaic acid, cysteamine, epidermal growth factor, hydroquinone (liposomal-delivered), lignin peroxidase, mulberry extract, niacinamide, Rumex occidentalis, triple combination therapy, tranexamic acid, 4-n-butylresorcinol, glycolic acid, kojic acid, aloe vera, ascorbic acid, dioic acid, ellagic acid and arbutin, flutamide, parsley, or zinc sulfate for melasma. Conclusions: Cysteamine, triple combination therapy, and tranexamic acid received strong clinical recommendations for the treatment of melasma. Cysteamine has excellent efficacy and is reported to have anti-cancer properties, but has not been directly compared with hydroquinone. Triple combination agents and tranexamic acid are effective, but carry theoretical risks for ochronosis and thrombosis, respectively. Natural compounds are associated with low risk for adverse events, but more research is needed to determine the efficacy, optimal formulation, and appropriate concentration of novel treatments.