Disorders of pigmentation are commonly seen, can cause significant distress, and often require a multi-modal approach in order to provide satisfactory outcomes.
Dyspigmentation is often multifactorial and can stem from a combination of both environmental (photo-induced) and intrinsic (constitutional skin pigmentation) factors.
The melanin biosynthesis pathway is complex and improved knowledge regarding these mechanisms may yield additional targets for therapy in the future.
The effect of light outside of the ultraviolet spectrum is becoming better elucidated. Visible light is able to illicit dyspigmentation in darker-skin individuals. Therefore, it is crucial to protect against the visible light spectrum when counseling patients on management of their pigmentary disorders.
For treatment of melasma, new skin-lightening options are becoming available and being integrated into clinical practice. These include methimazole, flutamide, cysteamine, and tranexamic acid.
Newer protocols for treatment of dyschromia are continually being developed as technology advances. Picosecond lasers represent one of the newer advances in treatment of melasma. Best practices for integration of these devices in clinical practice are currently underway.
Larger studies in diverse populations comparing medical and procedural interventions are occurring to determine the optimal combination of interventions for treatment of various dyschromia.
SKIN PIGMENTATION AND PIGMENTATION DISORDERS
Disorders of pigmentation can cause significant stress to patients, so available treatment options should be well-understood. Ultraviolet as well as visible light-induced changes to the skin may contribute to cutaneous pigmentation. In this chapter, the mechanisms involved in pigment formation will be detailed and the pigmentary conditions most likely to be seen by a cosmetic dermatologist will be discussed. There is a wide array of rarer dyschromia (lichen planus pigmentosus, erythema dyschromicum perstans) that is beyond the scope of this chapter. Cosmetic dermatologists are often faced with patients presenting with melasma, lentigines, postinflammatory hyperpigmentation, and periorbital hyperpigmentation. These conditions will be addressed in addition to some common treatment options. Depigmenting agents will be discussed in greater detail in Chapter 41 while energy-based devices will be discussed in greater detail in Chapter 26.
Although many factors contribute to skin color, including carotenoids or hemoglobin,1 the amount, quality, and distribution of melanin present in the epidermis are principally responsible for human skin color. The number of melanocytes in human skin is equal in all races. However, melanocyte activity and interaction with the keratinocytes account for skin color.2 In darker-pigmented individuals, melanocytes produce more melanin; the melanosomes are larger and more heavily concentrated, and they undergo degradation at a slower rate as compared to lighter-skinned individuals.3 Skin color is related to a combination of intrinsic and extrinsic factors. Experts refer to Constitutive skin color (CSC) as the genetically influenced color, whereas facultative skin color (FSC) will denote pigmentation influenced by environmental factors, most often referring to sunlight.4 Key concepts related to skin of color will be ...