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Cogan syndrome (CS) is a rare autoimmune disorder of unknown origin characterized by inflammatory ocular disease (mainly interstitial keratitis) and vestibulo-auditory manifestations (mainly acute onset hearing loss, tinnitus and vertigo), in the setting of a negative work-up for syphilis, with a variable risk of developing into a systemic disease. Systemic manifestations may occur in more than 70% of cases.
- Synonym(s): -
- Prevalence: Unknown
- Inheritance: Not applicable
- Age of onset: Childhood, Adolescent, Adult, Elderly
- ICD-10: H16.3
- OMIM: -
- UMLS: -
- MeSH: D055952
- GARD: 1421
- MedDRA: 10056667
CS is a rare disease with several hundred cases reported in the literature since 1945. The disease generally affects Caucasians with no gender specific prevalence.
The disease usually manifests in the first three decades of life. Typically, CS is characterized by ocular symptoms (non-syphilitic interstitial keratitis) and audiovestibular symptoms (sudden onset of tinnitus, vertigo and hearing loss) similar to those seen in Menière disease (see this term), with the interval between the onset of auditory and ocular symptoms being less than 2 years. Atypical CS is characterized by variable auditory and ocular features encompassing uveitis, superficial keratitis, iritis, episcleritis, glaucoma, and a delay of more than 2 years between the onset of ocular and auditory symptoms. Atypical and typical CS may be associated with the presence of systemic manifestations: vasculitis (see this term) involving cardiovascular (aortitis, aortic insufficiency, congestive heart failure, Raynaud's phenomenon), neurological (peripheral neuropathy, meningitis, encephalitis with hemiparesis, hemiplegia and aphasia) and gastrointestinal systems (diarrhea, melena and abdominal pain).
Etiology is not known but the mechanism of CS is now considered to be autoimmune and is characterized by the presence of specific anti-Cogan peptide antibodies to inner ear antigens and corneal structures and non-specific auto antibodies (such as anti-nuclear antibodies, anti-endothelial antibodies, anti-neutrophil cytoplasmic antibodies and rheumatoid factor).
The diagnosis of CS is often a challenge and is based on audiovestibular symptoms, evocative ocular inflammation and non-reactive serological testing for syphilis and Lyme disease (see this term) (in the absence of other differential diagnoses) as well as a good response to corticosteroid treatment. Pure tone audiogram is used to quantify hearing loss. Laboratory studies including blood count, urine analysis, serum electrolytes, creatinine, liver transaminases and erythrocyte sedimentation rate are performed to identify and assess systemic involvement.
Differential diagnosis includes syphilis and Menière disease, along with other infectious and inflammatory diseases such as Lyme disease, sarcoidosis, polyarteritis nodosa, granulomatosis with polyangiitis and Takayasu arteritis (see these terms).
Management and treatment
Treatment of CS traditionally consisted of systemic corticosteroids, with the ocular symptoms being more responsive than the vestibular-auditory symptoms. Diverse immunosuppressive agents (e.g. cyclophosphamide, methotrexate, azathioprine, cyclosporine, infliximab) have been used in cases of steroid dependence or resistance, with various degrees of success. Surgical intervention is reserved for conditions unresponsive to medication (e.g. cochlear implantation for unresponsive hearing loss, aortic valve replacement for aortic insufficiency resistant to medical therapy).
The prognosis is dominated by the risk of definitive deafness and by cardiovascular complications, notably aortic insufficiency. Severe visceral involvement or death related to cardiac or vascular involvement is unusual.
- Review article
- English (2012)