Pigmentary Disorders: Vitiligo, Melasma, and Disorders of Hyperpigmentation

This chapter reviews the current understanding of melanocyte biology, pigment regulation, and the molecular mechanisms underlying major acquired and genetic pigmentary disorders, including vitiligo, melasma, post-inflammatory hyperpigmentation, and drug-induced dyschromia. It critically evaluates the expanding therapeutic options for repigmentation in vitiligo — including JAK inhibitors, NB-UVB, and autologous melanocyte transplantation — as well as the complex management of melasma, addressing the limitations of conventional topical regimens and the promise of novel combinatorial approaches. The psychosocial burden of pigmentary disorders and the disparities in clinical recognition across skin phototypes are also examined.