1. What other tests are used to diagnose sarcoidosis?
A variety of tests may be ordered, both to help diagnose sarcoidosis and to determine the degree of organ involvement. Laboratory tests may include a liver panel, complete blood count (CBC), and calcium (both blood and urine levels may be elevated). Other tests may include a physical exam for skin lesions, pulmonary function tests as about 90% of the time there will be some degree of lung involvement, bronchoscopy (a procedure that uses a flexible tube to look at the lining of the airway and to biopsy the lung), chest x-ray, and gallium screening (radioactive gallium is used to evaluate inflammation). Biopsies of the skin, lungs, lymph nodes, and sometimes liver may also be needed, as may a thorough eye exam. A test called a slit-lamp examination may be used.
The cause is not well understood. It is not contagious. It is inflammatory and involves the immune system. It appears to have a genetic component as well as an environmental one. It has been reported both in related and unrelated individuals living in the same area. Up to 40 people per 100,000 are affected in the U.S., the majority of them between 20 and 40 years old. In the U.S. and in the Caribbean, sarcoidosis is more common in those of African descent, but worldwide about 80% of those with sarcoidosis are white. It is relatively common in Scandinavia and Northern Ireland, but rare in China, Japan, and Africa. For some reason, those who have moved from a part of the world where the prevalence is low to a part of the world where it is high tend to take on the risk of the higher prevalence area.
This article was last reviewed on March 10, 2015. | This article was last modified on March 10, 2015.
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