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KEY POINTS
Acquired disorders of hyperpigmentation are commonly seen in patients with skin of color but are particularly challenging to treat in this population.
Photoprotection is a safe and effective method of management.
Topical agents, including hydroquinone, combination, and azelaic acid creams, are first-line treatments for hyperpigmentation.
Glycolic acid and salicylic acid peels, and microdermabrasion have also demonstrated efficacy.
Q-switched (QS) neodymium-doped yttrium aluminium garnet laser, intense pulsed light, and nonablative fractional photothermolysis are promising therapies.
The erbium-doped yttrium aluminium garnet resurfacing laser, and lasers with shorter wavelengths (including the QS ruby and QS alexandrite laser) are not recommended for the treatment of acquired pigmentary disorders in patients with skin of color.
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Acquired disorders of hyperpigmentation, such as melasma [Figures 55-1 and 55-2] and postinflammatory hyperpigmentation (PIH), are among the most common conditions seen by dermatologists in patients with skin of color.1 They are often refractory to standard methods of lightening, and patients with darker skin types are at greater risk for developing undesired hypo- or hyperpigmentation from depigmenting agents or procedures.2 In this chapter, the treatment of hyperpigmentation with topical agents, peeling agents, and laser and light therapies is reviewed. Key principles of management include prevention of dyspigmentation with photoprotection, disruption of melanogenesis through tyrosinase inhibition, and melanin removal.
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In addition to ultraviolet (UV) A (290 to 320 nm) and ultraviolet UV B (320 to 400 nm) radiation, long-wave visible light (400 to 760 nm) has also been shown to induce melanin formation and pigmentation.3,4 Thus, photoprotection is a safe and effective first-line approach to depigmentation. Patients of all skin types should be advised to apply an oil-free, broad-spectrum UVA and UVB sunscreen with a sun protection factor (SPF) of at least 30.5 In June 2011, the U.S. Food and Drug Administration (FDA) released its final rule on sunscreens, clearly stating the testing and labeling requirements for “broad-spectrum” statements.6 As of December 2012, all major sunscreen manufacturers were mandated to accurately describe broad-spectrum coverage in accordance with these regulations. Seeking shade during the hours of 10:00 AM and 2:00 PM when UV rays are strongest, using photoprotective clothing and wide-brimmed hats, wearing sunglasses, and applying broad-spectrum sunscreens are essential approaches to avoid hyperpigmentation.7
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The most commonly used topical depigmenting agent is hydroquinone cream. Available in 2% over-the-counter formulations or higher concentrations by prescription, hydroquinone is a hydroxyphenol that acts on the tyrosinase enzyme to inhibit conversion of dihydroxyphenylalanine (dopa) to ...