The treatment of melasma: a review of clinical trials.

Melasma is an irregular brown or grayish-brown facial hypermelanosis, often affecting women, especially those living in areas of intense UV radiation. The precise cause of melasma remains unknown; however, there are many possible contributing factors. Because of its dermal component and tendency to relapse, melasma is often difficult to treat. The use of broad-spectrum (UVA + UVB) sunscreen is important, as is topical hydroquinone, the most common treatment for melasma. Other lightening agents include retinoic acid (tretinoin) and azelaic acid. Combination therapies such as hydroquinone, tretinoin, and corticosteroids have been used in the treatment of melasma, and are thought to increase efficacy as compared with monotherapy. Kojic acid, isopropylcatechol, N-acetyl-4-cysteaminylphenol, and flavonoid extracts are other compounds that have been investigated for their ability to produce hypopigmentation, but their efficacy, safety, or trial design indicates that the interventions would need further study before they could be recommended. Chemical peels, laser treatments, and intense pulsed light therapy are additional therapeutic modalities that have been used to treat melasma.