A Novel Treponema pallidum Subspecies pallidum Strain Associated With a Painful Oral Lesion Is a Member of a Potentially Emerging Nichols-Related Subgroup.

Background: Early syphilitic lesions are typically painless; however, several recent case studies have included patients with tender lesions and no evidence of concurrent infections. Here we present the manifestations and serological and molecular findings of a patient from New York State with a painful tongue lesion.

Methods: The diagnosis of syphilis was based on a combination of physical examination, serologic, pathologic, and immunohistochemical findings.