Increasing our understanding of pigmentary disorders.

This article focuses on developments in pigmentary disorders that extend dermatologists' understanding of the field. Areas that are reviewed include the basic biochemistry, pharmacology, and physiology of the melanocortin system; melanosome development; genetic diseases associated with pigmentary disorders; pigmentary disorders secondary to systemic disease; drug-induced hyperpigmentation; environmental exposure to chemicals; and primary disorders of hyperpigmentation such as melasma and lentigines. Basic, clinical, and epidemiological research, along with a number of clinical case reports, were included in the review. This article also reports on the new health-related quality-of-life instrument (MELASQOL) that has been developed for women with melasma.