recurrent aphthous stomatitis
a recurrent disease of unknown etiology, characterized by the appearance on the oral mucosa of one or more small round or oval ulcers that are covered by a grayish fibrinous exudate and surrounded by a bright red halo. The lesions usually persist for 7 to 14 days and then heal without scarring. A severe form is known as periadenitis mucosa necrotica recurrens. Called also aphthae, aphthous s., and canker sore.
Medical dictionary.
2011.