Cogan syndrome

Cogan syndrome
Classification and external resources
Specialty
ICD-10	M30.8
ICD-9-CM	370.52
DiseasesDB	32705
Patient UK	Cogan syndrome
MeSH	D055952

Cogan syndrome is a rare disorder characterized by recurrent inflammation of the front of the eye (the cornea) and often fever, fatigue, and weight loss, episodes of dizziness, and hearing loss. It can lead to deafness or blindness if untreated. The classic form of the disease was first described by D.G. Cogan in 1945.

Signs and symptoms

Cogan's syndrome is a rare, rheumatic disease characterized by inflammation of the ears and eyes. Cogan's syndrome can lead to vision difficulty, hearing loss and dizziness. The condition may also be associated with blood-vessel inflammation (called vasculitis) in other areas of the body that can cause major organ damage in 15% of those afflicted or, in a small number of cases, even death. It most commonly occurs in a person's 20s or 30s. The cause is not known. However, one theory is that it is an autoimmune disorder in which the body's immune system mistakenly attacks tissue in the eye and ear.

Causes

It is currently thought that Cogan's syndrome is an autoimmune disease. The inflammation in the eye and ear are due to the patient's own immune system producing antibodies that attack the inner ear and eye tissue. Autoantibodies can be demonstrated in the blood of some patients, and these antibodies have been shown to attack inner ear tissue in laboratory studies. Infection with the bacteria Chlamydia pneumoniae has been demonstrated in some patients prior to the development of Cogan's syndrome, leading some researchers to hypothesize that the autoimmune disease may be initiated by the infection. Chlamydia pneumoniae is a common cause of mild pneumonia, and the vast majority of patients who are infected with the bacteria do not develop Cogan's syndrome.

Diagnosis

While the white blood cell count, erythrocyte sedimentation rate, and C-reactive protein tests may be abnormal and there may be abnormally high levels of platelets in the blood or too few red blood cells in the blood, none of these findings is a reliable indicator of the disease. A slit-lamp examination is essential. Recent work has suggested that high-resolution MRI and antibodies to inner ear antigens may be helpful. Cogan syndrome can occur in children, and is particularly difficult to recognize in that situation.

Treatment

For more severe disease, oral corticosteroids may be necessary to reduce the inflammatory response. When large amounts of steroids are required or if the disease is severe and is not responding to steroid therapy, other immunosuppressive medications often are recommended. These immunosuppressive drugs include methotrexate, cyclophosphamide, cyclosporine or azathioprine. In some cases, combinations of these medicines are prescribed. Occasionally, if the disease has damaged blood vessels, cochlear implantation may need to be done to correct the problem.

Cinnarizine is mainly used to treat nausea and vomiting associated with motion sickness, vertigo, Ménière's disease, or Cogan's syndrome. Studies have shown it to produce significant improvement in hearing loss in some patients.

History

In 1945, the ophthalmologist David Glendenning Cogan (1908–1993) first described the "nonsyphilitic interstitial keratitis and vestibuloauditory symptoms" that would later bear his name. In 1963, the atypical form of Cogan syndrome, also known as "Logan Syndrome" was first described.

See also

• McCabe disease