Sarcoidosis is an inflammatory disease characterized by granulomas in affected tissues or organs of the body.
Most people have granulomatous inflammation in their lungs (about 90%) but many other organs can be affected. Examples of other organs are the eyes, the nervous system, lymph nodes, skin, the liver, the spleen and joints.
While clinical studies have found genetic risk factors in people with sarcoidosis, the underlying genetic traits are complex and involve multiple genes. The leading theory about what triggers sarcoidal inflammation is some type of environmental stimulus. Results from the largest epidemiological study to date (the NIH-sponsored ACCESS trial) found no one unifying environmental trigger and no single gene mutation responsible for causing sarcoidosis. Thus, the disease is thought to be a complex genetic disease with an environmental component.
Common symptoms
Since most individuals have sarcoidosis in their lungs, respiratory or chest symptoms are the most common symptoms (shortness of breath and cough). Other symptoms that can be frustrating, debilitating, and difficult to treat include symptoms of fatigue, joint pain, and vague chest pains. However, some individuals have no symptoms at all. Since sarcoidosis can affect any organ, individuals may have symptoms specific to their affected organ.
Sarcoidosis diagnosis
Sarcoidosis can be challenging to diagnose as no single diagnostic test currently exists. Doctors will often ask questions about the patient’s clinical history, obtain a high-resolution chest CT scan, and recommend a biopsy of the affected organ. These steps are taken to accurately diagnose sarcoidosis and exclude diseases that can appear similar to sarcoidosis (lymphoma and infections like tuberculosis are two examples of diseases that can share similar symptoms and appearance on chest imaging studies).
Sarcoidosis treatment approaches
Immune suppression is the mainstay of treating sarcoidosis. The first step is determining whether treatment with immune suppression will be necessary. Because sarcoidosis can resolve without therapy, it is important to hold off on therapy if the inflammation is asymptomatic or mild and not causing damage to organs.
Once the decision to treat sarcoidosis is made, the most common treatment is corticosteroids (often prednisone) and steroid-sparing treatments (such as methotrexate or azathioprine). Treatment typically lasts for 6 -24 months or longer. However, the length of treatment depends on the organs involved and whether symptoms relapse once treatment is tapered down or off.