Etiology • Occupational exposure—metals vapors (lead, mercury) • Therapeutic—metal salt deposits (bismuth, cis-platinum, silver,
gold); also nonmetal agents, such as chloroquine, minocycline, zidovudine, chlorpromazine, phenolphthalein, clofazimine, and others
Clinical Presentation • Focal to diffuse areas of pigmentary change • If heavy metals are the cause, a typical gray to black color is
gold); also nonmetal agents, such as chloroquine, minocycline, zidovudine, chlorpromazine, phenolphthalein, clofazimine, and others
Clinical Presentation • Focal to diffuse areas of pigmentary change • If heavy metals are the cause, a typical gray to black color is
seen along the gingival margin or areas of inflammation. • Palatal changes characteristic with antimalarial drugs and
minocycline • Most medications cause color alteration of buccal-labial
mucosa and attached gingiva. • Darkened alveolar bone with minocycline therapy (10% at
1 year, 20% at 4 years of therapy)
Diagnosis • History of exposure to, or ingestion of, heavy metals or drugs • Differentiation from melanocyte-related pigmentation by
biopsy if necessary
Differential Diagnosis • When localized: amalgam tattoo, mucosal melanotic macule,
melanoacanthoma, mucosal nevus, ephelides, Kaposi’s sarcoma, purpura, malignant melanoma, ecchymosis
• When generalized: ethnic pigmentation, Addison’s disease • If asymmetric, in situ melanoma must be ruled out by biopsy.
Treatment • Investigation of cause and elimination if possible
Prognosis • Excellent