 " Aphthous affectations " and " aphthous ulcerations " of the mouth are mentioned several times in the treatise " Of the Epidemics " ( part of the Hippocratic corpus , in the 4th century B.C ) , 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 . 
