Cogan syndrome
Encyclopedia
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.
(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.
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.
.
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.
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.
s 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.
History
In 1945 ophthalmologist David Glendenning CoganDavid Glendenning Cogan
-External links:* http://library.med.utah.edu/NOVEL/Cogan/career/...
(1908–1993) first described the "nonsyphilitic interstitial keratitis
Keratitis
Keratitis is a condition in which the eye's cornea, the front part of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves impaired eyesight.-Types:...
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.
Diagnosis
While the ESR, WBC, C-reactive protein test may be abnormal and there may bethrombocytosis
Thrombocytosis
Thrombocytosis is the presence of high platelet counts in the blood, and can be either primary or reactive...
or anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
, none of these findings are reliable indicators of
the disease. A slit-lamp examination
Slit lamp
The slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope...
is essential. Recent work has suggested
that high-resolution MRI
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
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 diseaseAutoimmune disease
Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...
.
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 ofthe 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
Vasculitis
Vasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of 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 corticosteroidCorticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
s 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
Immunosuppressive drug
Immunosuppressive drugs or immunosuppressive agents are drugs that inhibit or prevent activity of the immune system. They are used in immunosuppressive therapy to:...
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.