Dark Gums: Causes from Melanin to Medical Conditions

Gingival hyperpigmentation has multiple etiologies. Most are benign; some signal systemic disease.

Common Causes

1. Physiologic melanin: Genetic, more common in darker skin tones (melanin in basal/suprabasal layers). Bilateral, symmetric, asymptomatic.
2. Medication-induced: Minocycline, antimalarials (chloroquine), oral contraceptives, zidovudine, chemotherapeutics.
3. Smoking: "Smoker's melanosis" — nicotine stimulates melanocytes; reversible with cessation.
4. Amalgam tattoo: Impregnated mucosal particles from silver fillings; localized blue-black macule.
5. Endocrine: Addison's disease (ACTH/MSH ↑), Peutz-Jeghers syndrome (mucocutaneous macules), Cushing's.
6. Inflammatory: Lichen planus, chronic periodontitis.
7. Malignant: Melanoma (rare; asymmetric, irregular, changing), Kaposi sarcoma (HIV-associated).

Evaluation

• Dental exam: distribution, history, medications, smoking.
• Dermatology referral if atypical features (asymmetry, border irregularity, color variation, diameter >6 mm, evolution).
• Systemic workup if endocrine signs.

Treatment

• Benign: reassurance; gingival depigmentation (laser, scalpel, cryo) for aesthetics if desired.
• Drug-induced: review necessity; may fade after discontinuation.
• Smoking-related: cessation counseling.
• Pathologic: treat underlying condition.

New or changing pigmentation always warrants professional assessment.