Aphthous stomatitis caused by a reduction in numbers of CD4+ T cells may be implicated in RAS-type ulceration in HIV infection. The thickness of the mucosa may be an important factor in aphthous stomatitis. Usually, ulcers form on the thinner, non-keratinizing mucosal surfaces in the mouth. Factors which decrease the thickness of the mucosa increase the frequency of occurrence, and factors which increase the thickness of the mucosa correlate with decreased ulceration. The nutritional deficiencies associated with aphthous stomatitis (Vitamin B12, folate, and iron) can all cause a decrease in the thickness of the oral mucosa (atrophy). Local trauma is also associated
Aphthous stomatitis this condition. The origin of the word "canker" is thought to have been influenced by Latin, Old English, Middle English and Old North French. In Latin, "cancer" translates to "malignant tumor" or literally "crab" (related to the likening of sectioned tumors to the limbs of a crab). The closely related word in Middle English and Old North French, "chancre", now more usually applied to syphilis, is also thought to be involved. Despite this etymology, aphthous stomatitis is not a form of cancer but rather entirely benign. An aphtha (plural "aphthae") is a non specific term that refers to an ulcer