Definition of Sarcoidosis:

Sarcoidosis is a disease of unknown cause in which inflammation occurs in the lymph nodes, lungs, liver, eyes, skin, or other tissues.

Causes, incidence, and risk factors:

The cause of the disease is unknown. Sarcoidosis is marked by abnormal inflammatory masses (granulomas) in certain organs of the body. Granulomas are clusters of immune cells (macrophages, lymphocytes, and multinucleated giant cells). The disease can affect almost any organ of the body, although it most commonly affects the lungs. Sarcoidosis can be acute, subacute, or chronic.

Possible causes of sarcoidosis include:

• Hypersensitivity to environmental factors
• Genetics
• Extreme immune response to infection

The incidence varies widely according to race and sex.

It is more common in African Americans than Caucasians. Females are usually affected more frequently than males. Onset of the disease typically occurs between the ages of 20 and 40. Sarcoidosis is very rare in young children.