Recurrent aphthous stomatitis

Abstract

Recurrent aphthous stomatitis (RAS), also known as “canker sores,” is one of the most common diseases of the oral mucosa. It is characterized by the recurrent development of one to several discrete, painful ulcers in the mouth, often leading to difficulty in eating, drinking, and talking. RAS is world-wide in distribution and afflicts approximately 20% of the population. This disorder generally begins during adolescence, increases into adulthood, and then decreases with advancing age. Most patients are otherwise healthy. Although self-limited in nature, some individuals experience frequent and severe episodes, so that RAS may be associated with significant morbidity. Two disorders that are potentially related to RAS are “complex aphthosis” (CA) and Behçet's Disease (BD). In CA, recurrent oral and genital ulcers, or almost continuous oral ulcers (more than three), are seen. BD was originally described as the triad of oral ulcers, genital ulcers, and uveitis. However, it is now appreciated that BD is a complex multisystem disease. In both CA and BD, the mucosal ulcers are clinically and histologically indistinguishable from those that occur in RAS. For this reason, it has been suggested that these three processes present a continuum along the same disease spectrum, ranging from RAS, to CA, to BD. RAS has been divided into two forms, minor aphthous ulcers (MiAU), and major aphthous ulcers (MjAU). MiAU and MJAU, as the names imply, differ in the severity and frequency of active episodes. In both cases the clinical presentation of the oral ulcers typically progresses through four stages: premonitory, preulcerative, ulcerative, and healing. Histologic findings in RAS depend on the stage at which the biopsy was performed. Necrosis of individual epithelial cells evolves to more generalized destruction of the epithelial surface. A predominantly mononuclear inflammatory cell infiltrate is present, but vasculitis is not seen. Results of direct immunofluorescence studies have been variable and are generally considered nonspecific. The pathogenesis of RAS is unknown, despite multiple investigative studies. Possible etiologies that have been considered include genetic, nutritional, hormonal, allergic, psychological, traumatic, infectious, and autoimmune. An infectious agent and/or alteration in host immune function are considered most likely. Other disorders that may be associated with oral ulceration, and must be differentiated from RAS, include various infections (herpes simplex virus, coxsackie virus, yeast), mucocutaneous syndromes (erythema multiforme, cicatricial pemphigoid, pemphigus vulgaris, lichen planus), and certain systemic diseases (lupus erythematosus, inflammatory bowel disease, hematologic disorders). Some systemic, as well as topical, medications may also result in the development of RAS-like lesions. Unfortunately, there is currently no cure for RAS and no uniformly effective treatment. However, multiple therapeutic regimens exist that may provide significant symptomatic relief to the individuals with frequently recurrent or severe disease.