Syphilis is a sexually transmitted disease caused by Treponema pallidum (T. pallidum). In Japan, the number of cases decreased rapidly after the end of World War II due to the availability of relatively inexpensive diagnostic methods and effective antimicrobial agents such as penicillin. If a pregnant woman is infected with T. pallidum, it can infect the fetus through the placenta, resulting in miscarriage or congenital syphilis. Congenital syphilis has various late complications, such as sensorineural hearing loss, and is one of the reemerging infectious diseases that otolaryngologists should be familiar with. In this report, we describe a case of second-stage syphilis in which narrow band imaging (NBI) was useful for detecting mucosal lesions in the pharynx, with some discussion of the literature.
A 24-year-old woman was referred to our hospital with a 1-month history of sore throat. Examination revealed a mucosal lesion with a butterfly appearance extending from the anterior palatal arch to the upper pole of the palatine tonsil. NBI clearly showed the mucous membrane plaques with a butterfly appearance, which raised the possibility of a sexually transmitted disease, including syphilis, and after blood tests, culture tests, and biopsy of the lesion, the diagnosis of pharyngeal syphilis, stage 2 was established. NBI can clearly detect microscopic mucosal lesions that are difficult to distinguish by conventional white-light observation. The non-invasive nature of NBI and the fact that it does not require staining make it a useful tool for rapid and simple diagnosis of mucosal plaques in infectious diseases. However, given that the anti-TP antibody staining of biopsy specimens significantly aided in the diagnosis, histological examination should not be omitted. Since untreated syphilis patients with mucosal plaques can easily transmit the infection to others, prompt and appropriate diagnosis and treatment are necessary to help prevent the spread of syphilis.
