Multifocal or diffuse mucosal pigmentation
Mucosal pigmentation caused by exogenous substances can be divided into two categories depending on the pigment: heavy metal pigmentation of systemic origin and medication-induced pigmentation. Heavy metals pigmentation may be caused by lead, arsenic, or bismuth and often present as a linear discoloration along the gingival margin (the "lead line"). Even the bismuth present in Pepto-Bismol can cause a hyperpigmentation, although this is generally localized contact pigmentation on the dorsum of the tongue. It is believed that heavy metal ions excreted through the gingival crevicular fluid react with sulfites produced by gingival and periodontal bacteria, resulting in the deposition of heavy metal sulfides that are often black.
The medications that can cause drug-induced oral pigmentation include minocycline, antimalarials, clofazimine, and oral contraceptives. The drug or drug metabolites are pigmented substances that can be identified lying free or chelated to iron or melanin within the hard and/or soft tissues. Other drugs that supposedly cause oral pigmentation are likely related to a post-inflammatory hypermelanosis from a lichenoid interface drug eruption or from direct damage to the mucosa (such as chemotherapeutic agents). Although tetracycline can cause intrinsic staining of the teeth and bone, it does not generally cause mucosal pigmentation.
Mucosal pigmentation caused by endogenous pigment is usually melanotic or hemosiderotic in origin, the latter from breakdown of blood products. Melanotic pigmentation is seen in Peutz-Jeghers syndrome, Albright syndrome, hypoadrenal states (such as Addison disease), neurofibromatosis, LEOPARD syndrome, and Carney complex, to name a few.
K13.79 – Other lesions of oral mucosa
249405005 – Oral pigmentation
- Lead poisoning – May produce a "lead line," a narrow gray-black band along the gingival margin.
- Melanocytic nevi are generally single.
- Smoker's melanosis – Presents as multiple tan / brown melanotic macules on the buccal gingiva, usually of the mandibular teeth. This may be post-inflammatory in nature.
- Amalgam tattoo (exogenous pigmentation) – This is the most common intraoral pigmented lesion. Usually the amalgam tattoo is not elevated and particles of dental amalgam (silver filling material) can often be detected on periapical radiographs of the lesional site.
- Melanoacanthoma – This uncommon condition occurs most frequently in young adult African-American women, typically on the buccal mucosa. The lesion is generally much larger (1 cm or greater) than a melanocytic nevus, and it often follows a characteristic pattern of spontaneous involution over a period of days to weeks.
- Post-inflammatory hyperpigmentation by melanins is often seen in inflammatory mucosal conditions, especially those involving basal cells such as lichen planus. This often leads to a brown discoloration within the lesions of lichen planus.
- Pigmentation seen in patients infected with human immunodeficiency virus (HIV) is of unclear etiology but may be drug induced or intrinsic to the disease.
- Kaposi sarcoma – In early stages, may look macular, but it rapidly progresses to a tumorous stage.
- Melanoma – Has ill-defined or irregular margins and is unevenly pigmented, sometimes with areas of nodularity.
- Addison disease
- Peutz-Jeghers syndrome
- Laugier-Hunziker syndrome
- Gingival melanosis
- Heavy metals (silver, bismuth, arsenic, mercury)
- Albright syndrome