Cogan's Syndrome

●Cogan's syndrome (CS) is a chronic inflammatory disorder that most commonly affects young adults. Clinical hallmarks are interstitial keratitis (IK) and vestibuloauditory dysfunction, and associations between CS and systemic vasculitis, as well as aortitis, also exist. There are a range of pathologic findings, most of which reflect immune-mediated injury of the affected tissues; however, despite an association with systemic vasculitis, eye and inner ear specimens of those with CS do not reveal any evidence of vasculitis. The underlying mechanisms responsible for the eye and inner ear disease in CS are unknown.

●The predominant ocular feature of CS is IK, which typically causes eye redness, pain, photophobia, and blurred vision. Slit-lamp examination commonly demonstrates a patchy, deep, granular corneal infiltrate. IK is not essential for the diagnosis; ocular inflammation may involve other parts of the eye and may lead to iridocyclitis, conjunctivitis, episcleritis, anterior or posterior scleritis, or retinal vasculitis.

●The inner ear manifestations of CS are Ménière-like attacks consisting of vertigo, ataxia, nausea, vomiting, tinnitus, and hearing loss. Vestibular dysfunction may also cause oscillopsia, and caloric testing often reveals absent vestibular function. Recurrent episodes of inner ear disease frequently result in profound sensorineural hearing loss. Noninflammatory down-fluctuations in hearing may be difficult to distinguish from those of inflammatory origin. If hearing loss is associated with eye inflammation or other features of active CS or does not resolve within three to five days, an inflammatory origin is more likely.

●When present, the systemic vasculitis associated with CS is a large- or medium- to small-sized vessel vasculitis or an aortitis. The pattern of vessel involvement may be overlapping. Other systemic manifestations of CS include fever, fatigue, weight loss, lymphadenopathy, hepatomegaly, hepatitis, splenomegaly, pulmonary nodules, pericarditis, abdominal pain, arthralgia, arthritis, myalgia, and urticaria. An association with inflammatory bowel disease has also been observed.

●Evaluation of the patient with possible CS requires ophthalmologic examination to establish the presence of IK, scleritis, or episcleritis and to exclude other diseases and ocular pathology; neurologic and otologic examination to establish the presence of vestibuloauditory abnormalities; and rheumatologic examination to seek evidence of systemic vasculitis. We diagnose CS based upon the presence of characteristic inflammatory eye disease and vestibuloauditory dysfunction. The eye and inner ear are nearly equally likely to be the cause of presenting symptoms, while less than 5 percent of patients initially present with systemic manifestations

Bhopalwala. H