Middle-aged man with symmetrical lesions in his throat

Abstract

A 51-year-old man infected with HIV for more than 10 years visited our HIV clinic due to lesions in his throat. He had a CD4 T-cell count of >500 cells per μl and a HIV-RNA viral load of <20 copies per mm3. Nearly 3 months before this presentation, the patient participated in oral sex. At the clinic, he presented with a milky and (Fig. 1A ). He did not have any other symptoms on his skin. What is the diagnosis? Answer: Butterfly sign of pharyngeal syphilis. The patient had a history of syphilis 4 years prior to this visit. Although he was treated with amoxicillin 4 years prior, his serological tests for syphilis (STS) titer had remained positive at a low level. Laboratory testing revealed that his rapid plasma reagin (RPR) test result increased from 1:4 to 1:512 (normal value, <1), and his Treponema pallidum hemagglutination (TPHA) level had increased from 1280 to >40,960 (normal value, <1). Co-infections of HIV and syphilis are common [[1]Imahashi M. Izumi T. Watanabe D. Imamura J. Matsuoka K. Ode H. et al.Lack of association between intact/deletion polymorphisms of the APOBEC3B gene and HIV-1 risk.PLoS One. 2014; 9e92861Crossref PubMed Scopus (22) Google Scholar]. Notably, HIV patients often demonstrate prolonged STS positivity even after appropriate treatment. Thus, it is hazardous to diagnose syphilis solely based on a serological test. Pharyngeal syphilis accounts for 7% of syphilis cases [[2]Nishijima T. Teruya K. Shibata S. Yanagawa Y. Kobayashi T. Mizushima D. et al.Incidence and risk factors for incident syphilis among HIV-1-infected men who have sex with men in a large urban HIV Clinic in Tokyo, 2008–2015.PLoS One. 2016; 11e0168642Crossref PubMed Scopus (17) Google Scholar]. Due to the diversification of patients' sexual behaviors, healthcare providers should be aware of the oral manifestation of syphilis [[3]Dybeck Udd S. Lund B. Oral syphilis: a reemerging infection prompting Clinicians' alertness.Case Rep Dent. 2016; 20166295920PubMed Google Scholar]. The patient was treated with amoxicillin for a month, and the symptoms of pharyngeal lesions resolved rapidly. The picture shows the patient's soft palate after 2 months of follow-up (Fig. 1B). The authors disclose no financial or proprietary conflicts of interest with this publication. Consent was obtained and no patient identifiers are evident on the clinical image.