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KEY POINTS
Melasma is an acquired, relapsing condition of bilateral facial hypermelanosis.
Melasma predominantly affects women with skin of color.
An association exists with exposure to ultraviolet radiation, hormonal influences, and genetic predisposition, although the exact cause remains unknown.
Melasma negatively affects quality of life and can be socially stigmatizing.
First-line therapy entails sun protection and sun avoidance in conjunction with topical depigmenting agents.
The use of chemical peels, laser and light therapies should be reserved for refractory cases and used with caution in patients with skin of color to reduce the risk of postinflammatory hyperpigmentation.
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Melasma is an acquired, relapsing disorder of the skin characterized by bilateral, hyperpigmented, irregularly shaped macules and patches on sun-exposed areas of the face [Figure 51-1]. The terms chloasma and ‘mask of pregnancy’ are synonymous with melasma. Melasma is a common cause of hyperpigmentation worldwide, particularly in women of childbearing age with skin of color. Although several therapies have been developed for this often recalcitrant condition, effective long-term treatment for melasma remains a challenge, resulting in psychological distress and social stigmatization.
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EPIDEMIOLOGY AND PATHOGENESIS
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Melasma affects more than 5 million people in the United States alone and serves as a significant source of psychological distress with a negative impact on the quality of life reported by those who seek treatment for it.1,2 It predominantly affects women of Latino, African, Native American, and Asian descent.3 Fitzpatrick skin types III and IV are most commonly affected, as evidenced by a recent multicenter survey of women from nine countries.4 A population-based study of melasma in Hispanic women in the United States showed that 8.8% currently had melasma and 4% reported having had it in the past [Figure 51-2].5 Other studies, including surveys of patients presenting to dermatology clinics, have shown rates as high as 40%.6 The mean age of diagnosis is 34 years old, often years after the last pregnancy.4 Melasma tends to be much less common after menopause.
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The exact etiology of melasma has yet to be elucidated. There appears to be a strong association with hormones, ultraviolet (UV) light, and genetics. Recent data indicate that visible light may also play a role in the pathogenesis.
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Melasma has long been associated with hormonal changes, with patients noticing initiation or exacerbation of the condition during pregnancy, after oral contraceptive use, and occasionally during hormone replacement therapy.7,8 In a study conducted by Resnik,7 29% of women developed ...