Otosyphilis mimics immune disorders of the inner ear.

Syphilis is a well established cause of hearing loss. Sensorineural hearing loss may develop in the congenital or acquired form. The clinical course of the early acquired and late congenital forms are similar: sudden or rapidly progressive bilateral sensorineural hearing loss with mild vestibular symptoms. Cochleovestibular involvement in early acquired syphilis has been related to a basilar meningitis with lymphocytic infiltration of the labyrinth and VIIIth nerve. However, neurosyphilis and inner ear syphilis are not the same disease. Prompt diagnosis and treatment with corticosteroids and penicillin are mandatory to reduce the immune response and fibrosis of the labyrinth and the endolymphatic sac. Unfortunately, early acquired syphilis is frequently overlooked in the differential diagnosis of other forms of sensorineural hearing loss, particularly autoimmune inner ear disease. Given the increasing number of luetic infection cases, especially in immunocompromised patients, this condition should be considered in any sexually active patients affected by sudden hearing loss. Cases of inner ear syphilis are presented. Immunopathology of luetic inner ear infection is discussed and compared with immune disorders of the inner ear.