Some suggest that screening for celiac disease should form part of the routine work up for individuals complaining of recurrent oral ulceration. Many of the systemic diseases cause other symptoms apart from oral ulceration, which is in contrast to aphthous stomatitis where there is isolated oral ulceration. Patch testing may be indicated if allergies are suspected (e.g. a strong relationship between certain foods and episodes of ulceration). Several drugs can cause oral ulceration (e.g. nicorandil), and a trial substitution to an alternative drug may highlight a causal relationship.Tissue biopsy is not usually required, unless to rule out other suspected conditions such as oral squamous cell carcinoma. The histopathologic appearance is not pathognomonic (the microscopic appearance is not specific to the condition). Early lesions have a central zone of ulceration covered by a fibrinous membrane. In the connective tissue deep to the ulcer there is increased vascularity and a mixed inflammatory infiltrate composed of lymphocytes, histiocytes and polymorphonuclear leukocytes. The epithelium on the margins of the ulcer shows spongiosis and there are many mononuclear cells in the basal third. There are also lymphocytes and histiocytes in the connective tissue surrounding deeper blood vessels near to the ulcer, described histologically as "perivascular cuffing". Classification
Aphthous stomatitis has been classified as a type of non-infectious stomatitis (inflammation of the mouth).
There is some evidence that small subpopulations of clinical isolates are more capable of colonizing the heart throughout the course of infection, but cardiac manifestations are usually sporadic and may rely on a combination of bacterial factors and host predispositions, as they do with other strains of cardiotropic bacteria. Recent outbreaks
According to the Centers for Disease Control and Prevention (CDC) there are about 1,600 cases of listeriosis annually in the United States. Compared to 1996–1998, the incidence of listeriosis had declined by about 38% by 2003. However, illnesses and deaths continue to occur. On average from 1998 to 2008, 2.4 outbreaks per year were reported to the CDC.Some notable ones are listed below. 2002 United States outbreak
A large outbreak occurred in 2002, when 54 illnesses, 8 deaths, and 3 fetal deaths in 9 states were found to be associated with consumption of contaminated turkey deli meat. 2008 Canadian listeriosis outbreak
An outbreak of listeriosis in Canada linked to a Maple Leaf Foods plant in Toronto, Ontario killed 22 people. 2011 United States listeriosis outbreak
On September 14, 2011, the U.S. Food and Drug Administration warned consumers not to eat cantaloupes shipped by Jensen Farms from Granada, Colorado due to a potential link to a multi-state outbreak of listeriosis.