Abstract
We present a case of sudden sensorineural hearing loss occurring as a complication of secondary syphilis. Syphilis affecting the inner ear, or otosyphilis, is well described in historical literature, but has rarely been reported in recent times. However, following the resurgence of syphilis in the UK, unusual manifestations such as otosyphilis are likely to be seen increasingly commonly.
Case Report
A 44-year-old homosexual man presented with a two-week history of deafness. This had come on suddenly, and worsened over the subsequent week to the point where he could hear no sound at all with either ear. He also experienced some tinnitus and vertigo initially, which later settled. Two weeks after the onset of deafness, he developed an erythematous macular rash on his trunk and limbs.
Investigation by the ear, nose and throat department demonstrated a profound bilateral sensorineural deafness but failed to identify a cause. He received a course of steroids with no benefit. Magnetic resonance imaging (MRI) of his brain and inner ear was normal.
Three months prior to his deafness, he had developed an enlarged inguinal lymph gland. This had been biopsied and histology was reactive. He had no other significant past medical history and took no regular medication.
He was seen in our clinic seven months after the onset of his symptoms, at which point his rash was still present but had faded (Figure 1). Examination was otherwise normal save for his deafness. Serological testing for syphilis was performed and was positive (treponemal enzyme immunoassay [EIA], Treponema pallidum particle agglutination assay [TPPA] and IgM-positive, and rapid plasma reagin [RPR] test 32 units). A diagnosis of secondary syphilis was made, and he was admitted for 21-days treatment with four-hourly intravenous benzylpenicillin (2.4 g) and prednisilone (60 mg) daily. His rash quickly resolved, but unfortunately there was no improvement in his hearing.
Erythematous macular rash on the trunk
A lumbar puncture performed before starting the treatment showed normal cell count, protein and glucose. Cerebrospinal fluid (CSF) treponemal EIA and TPPA were positive and CSF RPR test was negative. HIV testing was negative, as was an autoimmune profile.
Discussion
Otosyphilis can occur both in congenital and acquired syphilis. In the latter, hearing loss may occur in early or late stages of the disease.
Sensorineural deafness in early-acquired syphilis may be seen as part of an acute meningitic syndrome. Importantly however, early syphilis may present simply as an acute labyrinthitis or vestibular neuronitis, and classical signs of secondary syphilis may be minimal. 1 Hearing loss is usually of sudden onset, bilateral and rapidly progressive, often with only minor vestibular symptoms. 2
Eighth nerve involvement may result from basilar meningitis, with the associated CSF abnormalities of a pleocytosis, raised protein and positive treponemal serology. Cases have also been reported where the CSF was normal, postulating that spirochaetal invasion of the perilymph resulted in inflammation confined to the labyrinth and cochlea. 2
Late syphilitic hearing loss is thought to result primarily from osteitis and periosteitis of the temporal bone, leading to degeneration of the cochlea and labyrinth. 3 CSF studies are usually normal. Conductive deafness because of bony fixation of the ossicles has also been described. Deafness can also result from eighth nerve involvement in late neurosyphilis.
A presumptive diagnosis of otosyphilis may be made on the basis of positive serology and the exclusion, as far as is practicable, of other pathology of the inner-ear. There are numerous other causes of sudden sensorineural hearing loss, but in practice most cases are idiopathic. If no diagnostic clues are provided by history or clinical examination, further useful investigation is mainly limited to MRI and simple blood tests such as full blood count, erythrocyte sedimentation rate and blood glucose. 4 Many viruses have been implicated in causing sensorineural deafness. There are rare reports of sudden onset of hearing loss occurring as part of an HIV seroconversion illness 5 or as a manifestation of chronic HIV infection, 6 so HIV testing is also indicated.
Recommended treatment is the same as for neurosyphilis. 7 Published series vary widely in the dosage of penicillin used and duration given, along with the usage of steroids in most cases. Evidence of the additional benefit of steroids is limited, with no prospective controlled trials. The little data that exist on the treatment of early disease suggests complete recovery may occur if treatment is commenced within weeks of symptom onset. 1 Outcome is generally poor when symptoms have been present for longer periods, or if hearing loss is absolute prior to treatment. 8
In conclusion, syphilis should be considered as a cause in all cases of sudden sensorineural hearing loss. If diagnosed early, hearing loss may be reversible.