Clinical Value of the Fluorescent Quantitative Polymerase Chain Reaction in the Diagnosis of Primary Syphilis

Objective： To evaluate the clinical value of fluorescent quantitative polymerase chain reaction （FQ-PCR） in the diagnosis of primary syphilis. Methods： 68 swab specimens were collected from patients suspected of infecttion with primary syphilis attending two STD clinics （Guangzhou Institute of Dermatovenerology and the First People＇s Hospital of Guangzhou city）, from September 1998 to December 2000. Analysis： by FQ-PCR, darkfield microscopy （D-F） for Treponema pallidum （TP）, and serologic testing for syphilis （STS）. Results： Of 68 patients, 30 （44.12%） were positive for TP by QF-PCR assay, 19 （27.94%） were positive for TP by D-F, 33 （48.53%） were positive for TP-IgG antibody by RPR, and 42 （61.76%） were positive for TP-IgG antibody by TPHA. There are significant differences in detection between D-F and TPHA （P〈0.05）, but there is no difference with RPR （P〉0.1）. Conclusion： This data shows that QF-PCR is a convenient, reliable and rapid method for diagnosis of primary syphilis, and may be an effective clinical assay in the detection of TP.

The Great Imitator:Atypical Cutaneous Manifestations of Primary Syphilitic Chancre

Objective To analyze the reasons of misdiagnosis of primary syphilitic chancre and strengthen the understanding of atypical features of this disease.Methods A case series of twenty-seven challenging primary syphilis patients who were not immediately recognized as chancre was included in our study.The clinical data including the patients’age,sex,skin lesions,HIV status,syphilis serologic test results,treatment,and follow-up results were collected.Hematoxylin-eosin and immunohistochemistry staining of skin biopsy sections were reviewed.Results Four female cases with extragenital chancres presenting as erythema or erosive skin lesions on the nipple were misdiagnosed as Paget’s disease or eczema.The disorder of missed or misdiagnosed male cases manifested as syphilitic balanitis or multiple chancres on the penis root and adjacent pubis rather than coronal sulcus or frenum.Patients with nonreactive nontreponemal tests at initial presentation were also easily missed or misdiagnosed.Conclusion Primary syphilis presenting as multiple lesions rather than a single chancre,at atypical locations,or with a nonreactive nontreponemal test result,tends to be missed or misdiagnosed.

Early Syphilis Presenting as Thickened Penile Plaques With an Embedded Recurrent Ulcer (Chancre Redux): A Case Report

Introduction:The manifestations of syphilis are varied,and serology can establish the diagnosis early,especially in rare cases.We report a case of chancre redux(a rare recurrence of primary syphilis),which was embedded within a secondary syphilitic penile skin plaque.There were missed opportunities at earlier diagnosis as serology for syphilis was not ordered.Case presentation:A 56-year-old man presented with thickened penile plaques for five months.He reported a small penile ulcer approximately one month prior.There was no history of other skin lesions or rash.However,clinically there was an asymptomatic,indurated ulcer embedded within a plaque which was swab-positive for syphilis by PCR.A punch biopsy of a plaque was spirochaete-positive using an immunoperoxidase stain.The patient’s lesions resolved three weeks after treatment with intramuscular benzathine penicillin.Discussion:Uncommonly reported even in the preantibiotic era,chancre redux is now rare.The ulcer usually recurs at or near the site of the original chancre,and has similar morphological features.The skin lesions of secondary syphilis can exhibit remarkable morphological variety.The most common skin manifestation,a generalized macular rash,was not present at any time in this case.Rather,there were only a couple of nonspecific penile plaques.If biopsy is performed,histologic findings are variable,though typically the inflammatory infiltrate includes plasma cells.A special immunoperoxidase stain can highlight spirochaetes in biopsy sections.Conclusion:This case highlights the importance of considering syphilis in the differential diagnosis of persistent,atypical penile lesions and underscores the need for appropriate serological testing in such instances.