Otosyphilis as a rare cause of secondary benign paroxysmal positional vertigo: a case report

Otosyphilis is a rare cause of audiovestibular dysfunction that can easily be misdiagnosed. Here, we report a rare case in which a patient presented with secondary benign paroxysmal positional vertigo (BPPV) 2 weeks after symptoms of otosyphilis appeared. The Dix–Hallpike test showed a classical response in the head-hanging left position. The patient was treated with intravenous penicillin G and the canalith repositioning maneuver, which completely resolved the vertigo. The patient's audiovestibular symptoms resolved gradually. The elevated cerebrospinal fluid (CSF) white blood cell (WBC) count returned to normal and the results of the Treponema pallidum particle agglutination (TPPA) test were negative at the 3-month follow-up. This report suggests that otosyphilis should be considered in the differential diagnosis of audiovestibular dysfunction in patients at risk. Additionally, clinicians should remain vigilant about the possibility of secondary BPPV in patients with otosyphilis who report positional vertigo.