Depigmenting and bleaching agents: coping with hyperpigmentation.

Since the introduction of hydroquinone as a skinlightening agent in 1961, several products with bleaching properties have been used for the treatment of pigmentary disorders of the skin.1 The most important medical indications for the use of these agents are melasma and postinflammatory hyperpigmentation, although they have also been used as alternative options for the treatment of ephelides, solar lentigenes, nevi, and lentigo maligna. This article reviews the most commonly used bleaching agents, discusses their mechanism of action, and focuses on their efficacy and safety in treating unwanted skin pigmentation. Based on our current knowledge, the ideal bleaching agent has to fulfill certain pharmacologic criteria. It should have a potent bleaching effect with a rapid time of onset (less than 2 to 3 months), carry no shortor long-term side effects, and lead to a permanent removal of undesired pigment. Most of the currently available bleaching or depigmenting agents cause a temporary removal of hyperpigmentation, which usually recurs after discontinuation of therapy. Presently, there are three categories of bleaching agents (Table 1): phenolic compounds, nonphenolic compounds, and combination formulas.