Ingestion of, or exposure to, heavy metals*, such
as lead, mercury, gold, arsenic and bismuth, can
lead to diffuse pigmentation of oral mucosa. The
pigmentation may be dark blue, gray or black and
commonly involves the marginal gingiva. Diffuse
mucosal ulceration and a metallic taste may
also be noted. Extraoral manifestations may be
a clue to the diagnosis, and include dermatitis,
tremors, mental changes, headache, fatigue, and
gastrointestinal upset. Management of suspected
heavy metal intoxication involves referral for
diagnostic workup