Observations on the diagnosis of recurrent aphthous stomatitis.

The case histories of four patients--one with recurrent aphthous stomatitis who had a "correctable" deficiency, one with pemphigus vulgaris, one with cicatricial pemphigoid, and one with lichen planus--are reviewed. All had oral ulcerations resembling recurrent aphthous stomatitis. These cases demonstrate the heterogeneity of lesions that might be diagnosed as "canker sores." The necessity for clinical correlation and specific laboratory, histopathologic, and immunopathologic diagnostic tests is delineated.