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KEY POINTS
Hypopigmentation disorders are the third most common reason for patients with skin of color to seek dermatologic treatment. Dermatologists should know how to recognize and treat these conditions, with special sensitivity to their psychological aspects.
The causes of hypopigmentation can be divided into two categories based on the pathogenesis: melanopenic and melanocytopenic. The causes can also be congenital or acquired.
Hypopigmentation disorders can often be treated successfully with topical, oral, surgical, light- or laser-based techniques, either alone or in combination.
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Hypopigmentation and depigmentation disorders can be divided into two categories based on their pathogenesis: melanopenic or melanocytopenic. The melanopenic category refers to disorders of melanin pigment production by the melanocytes, whereas the melanocytopenic category refers to disorders that lead to a reduction in the numbers, or the complete absence, of melanocytes. Clinically, melanocytopenic macules are milky-white, due to the reflection of incident light. Under Wood lamp skin examination, they appear stark white in contrast to the surrounding skin. The skin undergoing melanopenic processes can be various degrees lighter than the normal skin color.
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There are a number of disorders of hypopigmentation and depigmentation that are clinically relevant. Those that will be discussed in this chapter are tinea versicolor (TV), idiopathic guttate hypomelanosis (IGH), pityriasis alba (PA), postinflammatory hypopigmentation (PIH), piebaldism, and progressive macular hypomelanosis (PMH).
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The incidence of some of these conditions, such as PA, is increased in individuals with skin of color, whereas others occur equally in Caucasians and those with skin of color. Hypopigmentation disorders are the third most common reason for patients with skin of color to seek dermatologic treatment.1 These disorders are of great concern because of the marked contrast between the affected and normal skin, and they can be psychologically devastating. Dermatologists should know how to recognize and treat these conditions, with special sensitivity to their psychosocial effects on patients.
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TV, caused by the fungus Pityrosporum ovale (also known as Microsporum furfur, Malassezia furfur, or Pityrosporum orbiculare), is a superficial infection with a distinctive clinical appearance. It manifests as hypopigmented or hyperpigmented slightly scaly macules and patches that are an ivory to tan color and up to several centimeters in diameter. The lesions predominantly affect the sebaceous areas of the trunk, arms, neck, and face [Figure 48-1]. Patients sometimes present with follicular hypopigmentation, although there is no racial predilection [Figure 48-2].2 The dyschromia that results from the infection is often more apparent in individuals with skin of color because of a greater contrast between the dyschromia and the patient’s dark skin.
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