Recurrent aphthous stomatitis: clinical characteristics and evidence for an immunopathogenesis.

Recurrent aphthous stomatitis is one of the most common diseases affecting the oral mucosa, and one of its variants is the most painful affliction of the oral mucosa. The lesions of recurrent aphthous stomatitis can be manifested as part of a broad spectrum of clinical disease ranging from the common minor aphthous ulcers to Behçet's syndrome. Differential diagnosis, although not often difficult, must include many conditions capable of producing erosive and ulcerative oral mucosal lesions. The salient features of recurrent aphthous stomatitis suggest that it is a heterogeneous entity. Recent immunologic investigations have focused attention on a possible immunopathogenesis and the evidence for this is reviewed.