Oral syphilis lesions--a diagnostic approach and histologic characteristics of secondary stage.

Syphilis is among the oldest recognized sexually transmitted diseases. In the past decade, its incidence has risen significantly in the developed world. Oral syphilitic lesions, the most common extragenital sign of infection, are a diagnostic challenge to dentists, who are usually the first to examine the oral lesions. Biopsies are occasionally the first examination performed, but histologic findings are considered nonspecific. We present two new cases as well as an additional 25 published cases, suggesting that plasma cell arteritis and plasma cell neuritis is a combination that has not been reported in any other pathologic condition of the oral cavity and may be specific enough to direct the clinician toward a diagnosis of syphilis prior to clinical confirmation.