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Rationale for the use of topical corticosteroids in melasma.

Corticosteroids have been combined with other agents in the treatment of melasma for years. In early studies by Kligman and Willis, topical dexamethasone as monotherapy produced little depigmentation even after 3 months of therapy. A significant concern is that topical corticosteroids used alone in this setting, especially on the face, may result in epidermal atrophy, telangiectasia, rosacea-like erythemas, acne, and perioral dermatitis. Topical corticosteroids, however, including low-potency fluocinolone acetonide, also exert an anti-metabolic effect, resulting in decreased epidermal turnover, and, thus, may produce a mild depigmenting effect. When used in combination with tretinoin and hydroquinone in the treatment of melasma, fluocinolone acetonide 0.01% suppresses biosynthetic and secretory functions of melanocytes, and thus melanin production, leading to early response in melasma, synergy among the three agents, and no significant side effects over an 8-week period.