Description of clinical cases and available diagnostic tools of oropharyngeal syphilis: a systematic review of the literature.

Introduction: Syphilis is a systemic bacterial infection caused by the spirochete Treponema pallidum. Head and neck mucosal manifestations of syphilis can be observed in each and all of primary, secondary and tertiary syphilis, especially in the secondary one. Therefore, oropharynx is an unusual localization of syphilitic lesions, mainly represented by ulcerous lesions, tissue hypertrophy, mucosal patches and cancer-like lesions. Serology is routinely considered the gold standard for the screening and diagnosis of syphilis. However, direct detection is routinely used during polymerase chain reaction (PCR) of oropharyngeal tissue and suspicious cervical lymphadenopathies.

Methods: PRISMA 2020 guidelines were applied to make a systematic literature review with the aim to make an overview of clinical manifestations and diagnostic tools of oropharyngeal syphilitic infection. A computerized MEDLINE search was performed using the PubMed, Web of Science and Cochrane databases.

Results: The intended analysis was based on 38 papers, including a total of 55 cases. The main localization of oropharyngeal infection was the tonsil (71%), followed by lateral and posterior wall of oropharynx (16%). Ulcerous lesions were the most frequently encountered lesions in the primary syphilis (56%) and secondary syphilis (36%), whereas gumma's lesions were encountered in the tertiary syphilis (57%). Diagnosis based on serological assays was used in combination with non-treponemal methods to determine disease activity (80% cases).

Conclusions: Oropharyngeal syphilis has historically been referred to as the "great imitator" due to its highly variable manifestations, which can resemble malignancies. Physicians have to recognize oropharyngeal luetic features early, in order to set up an effective diagnostic and therapeutic work-up.