Contact stomatitis is an immunologic reaction of the oral mucosa to any one of a variety of materials to which the mucosa might be exposed, including (but not limited to) flavoring agents, dental amalgam, and preservatives.

There is no age, sex or racial predilection associated with contact stomatitis, although most affected patients are adults.

Patients may complain of pain, tenderness or a burning sensation, and these symptoms may vary in their intensity depending on contact with the offending agent.

Contact reactions often appear from within a few days to a few weeks of exposure to the causative agent, although in some cases, hypersensitivity may not develop until after years of exposure. Lesions remain as long as the agent is in contact with the mucosa and resolution occurs after removal of the agent. Usually resolution is seen after 1-2 weeks, however, some lesions may take as long as 1-2 months to resolve.