Oral syphilis – A case report

17 June, 2019 / clinical
 Dr Maria Taheny, Dr Rebecca Lees, Mr Roger Currie  

Dr Maria Taheny1, Dr Rebecca Lees2, Mr Roger Currie3, University Hospital Crosshouse


Syphilis is a sexually transmitted infection caused by the spirochaete Treponema pallidum. Oral manifestations are usually in the form of a painless ulcer, known as a chancre, at the site of entry of the infection. This is a case report of a patient who was referred to the OMFS clinic with suspected oral cancer, but following investigation was diagnosed with syphilis. This report highlights the importance of considering syphilis in the provisional diagnoses of white/red patches and ulcerative lesions of the oral mucosa. 


A 38-year-old man was referred to the oral and maxillofacial surgery clinic by his GMP with regards to a non-healing ulcer on his right lower lip. The GMP had prescribed a course of Nystatin, followed by Fluconazole with no improvement. At this point the patient was referred to the OMFS unit due to clinical suspicion of oral malignancy. 

The patient attended the clinic complaining of an ulcer on his lower lip which he originally thought was a cold sore but grew suspicious when it increased in size and did not heal over a four-week period. He also mentioned being aware of a persistent white patch under his tongue and recurrent oral ulceration for three months. 

Medically, the patient was diagnosed with HIV and subsequent Hepatitis C co-infection five years previously and was receiving the antiretroviral drugs Dolutegravir and Rezolsta. He was a smoker of 20 cigarettes per day and drank 18 units of alcohol per week. He worked as a hotel manager.

Clinical examination revealed a large ulcer on the right lower lip which measured approximately 1.5cm x 1cm. It was a mixed red and white ulcer which appeared indurated. (Figure 1). There was also a red and white patch on the left ventral tongue (Figure 2) and some small ulcers on the posterior hard palate. Urgent incisional biopsies of the lip and tongue lesions were carried out.

The results showed both biopsies to be in keeping with the clinical impression of syphilis. The key diagnostic feature from the histopathology was “numerous corkscrew-like spirochaetal organisms especially prominent within the surface epithelium” which were visible after staining for Treponema pallidum (Figure 3). 

The patient’s blood tests were also positive for Syphilis IgM and Treponema pallidum antibodies. Liaison with the Infectious Diseases team resulted in the patient receiving intramuscular benzathine penicillin treatment. 


Syphilis can be congenital or acquired. Acquired syphilis is sexually transmitted and has three clinical stages: primary, secondary and tertiary.2 It can present as various oral manifestations, mainly at the secondary stage2. Oral manifestations are, in many cases, one of the first signs of the disease and can guide the correct and early diagnosis, which is of great importance for the treatment of the condition3

These manifestations include ulcerated lesions, white plaques, verrucous lesions, or other atypical lesions1. The lip represents the most common site of involvement, followed by the tongue and the tonsils. 2,4,5

In this case, the patient had sexually-transmitted HIV and had already undergone serology investigation for syphilis, therefore secondary syphilis was in the provisional diagnoses. However, if the patient did not present with this history, the suspicion of syphilis would not have been as obvious. The other provisional diagnoses were aphthous ulcers secondary to immunocompromise, lichenoid reaction, dysplasia or SCC. 

The analysis of a suspected patient’s clinical history, combined with physical examination and serological assays normally allows a conclusive diagnosis of the disease to be reached, and biopsy is not normally required as an initial diagnostic resource2. In this case, biopsy was performed to rule out oral malignancy or dysplasia, particularly given the fact that the patient had risk factors for oral cancer, including smoking and immunocompromise and both the tongue and lip lesions had been present for more than three weeks. 

The therapy of choice for syphilis is benzathine penicillin2, which is delivered intra-muscularly1. For patients hypersensitive to penicillin, oral administration of doxycycline 100mg twice a day for 14 days or tetracycline 500mg four times a day for 14 days is indicated, with similar efficacy2.


This case highlights that syphilis can present intra-orally and represent a diagnostic challenge because of the broad spectrum of clinical appearances, which can be similar to other oral mucosal lesions. A thorough medical and social history is vital in reaching a definitive diagnosis so the appropriate treatment can be provided. 


1. Barbosa de Paulo et al. Oral Manifestations of Secondary Syphilis. International Journal of Infectious Diseases, 2015-06-01, Volume 35, Pages 40-42

2. Seibt et al. Secondary syphilis in the oral cavity and the role of the dental surgeon in STD prevention, diagnosis and treatment: a case series study. Brazilian Journal of Infectious Diseases, 2016-07-01, Volume 20, Issue 4, Pages 393-398

3. WHO Guidelines for the Treatment of Treponema pallidum (syphilis) Geneva: World Health Organization; 2016

4. Shim HJ. Tertiary syphilis mimicking hepatic metastases of underlying primary peritoneal serous carcinoma. World J Hepatol. 2010;2:362–6.

5. de Andrade et al. Oral Findings in Secondary Syphilis. Med Oral Patol Oral Cir Bucal. 2018 Mar 1;23 (2):e138-43.

6. https://binged.it/2QfMtEi


2BDS MFDS RCPS(Glasg) Dip Con Sed (Ncl), Speciality Doctor OMFS

3FDS FRCS FFST (Ed) FRCS (OMFS), Consultant Oral and Maxillofacial Surgeon

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