The hard penile circumferential fold as the presenting finding in primary syphilis: report of six cases.

Background: Six patients with firm circumferential folds located in the balanic sulcus of the penis were studied.
Objective: The purpose of the study was to determine the origin of the lesions.
Methods: These patients were examined clinically, with dark-field examination when possible and with a serologic test for syphilis.
Results: All patients had reactive serologic tests for syphilis and had enlarged, firm, nontender, inguinal lymph nodes.
Conclusion: Although we were unable to prove with certainty that the origin of these folds was syphilitic, all patients had clinical and serologic findings that supported the diagnosis of primary syphilis.