Aphthous stomatitis century BC), although it seems likely that this was oral ulceration as a manifestation of some infectious disease, since they are described as occurring in epidemic-like patterns, with concurrent symptoms such as fever. Aphthous stomatitis was once thought to be a form of recurrent herpes simplex virus infection, and some clinicians still refer to the condition as "herpes" despite this cause having been disproven. The informal term "canker sore" is sometimes used, mainly in North America, either to describe this condition generally, or to refer to the individual ulcers of this condition, or mouth ulcers of any cause unrelated to
Aphthous stomatitis history, suggesting that some people are genetically predisposed to suffering with oral ulceration. HLA-B12, HLA-B51, HLA-Cw7, HLA-A2, HLA-A11, and HLA-DR2 are examples of human leukocyte antigen types associated with aphthous stomatitis. However, these HLA types are inconsistently associated with the condition, and also vary according to ethnicity. People who have a positive family history of aphthous stomatitis tend to develop a more severe form of the condition, and at an earlier age than is typical. Stress has effects on the immune system, which may explain why some cases directly correlate with stress. It is often stated that in studies of