Chemically Induced Depigmentation of Skin and Hair

The document from 1990 provides a comprehensive overview of how various chemicals can cause depigmentation of skin and hair. It differentiates between irreversible depigmentation due to damage to hair bulb melanocytes by agents like ionizing radiation and alkylating agents, and reversible effects from chemicals like thiols and phenolic compounds. It highlights the distress caused by depigmentation, particularly in dark-skinned individuals, and notes that certain topical medicaments can destroy melanin in hair. The document reports cases of disfiguring leukomelanoderma from cosmetic products, occupational leukoderma from phenolic compounds, and reversible skin and hair depigmentation from various substances including anesthetics, adhesives, and tranquilizers. It also discusses the depigmenting action of dicarboxylic acids and the effects of chemicals on the hair growth cycle. The conclusion emphasizes the need for better control of depigmenting substances in cosmetics, the underreporting of pigmentary changes from chemicals, and the implications of these findings for drug and cosmetic use, as well as for understanding melanogenesis and related disorders.