Cogan syndrome

Cogan syndrome
Classification and external resources
DiseasesDB	32705
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.

History

In 1945 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 was first described.

Diagnosis

While the ESR, WBC, C-reactive protein test may be abnormal and there may be thrombocytosis or anemia, none of these findings are reliable indicators 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.

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 hypothesis 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.

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.

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 (Rheumatrex), cyclophosphamide (Cytoxan, Neosar), cyclosporine (Neoral, Sandimmune) or azathioprine (Imuran). 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. Studies have shown it to produce significant improvement in hearing loss in some patients.

Related disorders

• McCabe disease

References

it:Sindrome di Cogan pl:Zespół Cogana