Definition of Sarcoidosis:

Sarcoidosis is a disease 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. In sarcoidosis, tiny clumps of abnormal tissue (granulomas) form in certain organs of the body. Granulomas are clusters of immune cells.

The disease can affect almost any organ of the body, but it most commonly affects the lungs.

Possible causes of sarcoidosis include:

• Extreme immune response to infection
• High sensitivity to environmental factors
• Genetic factors

The condition is more common in African Americans than Caucasians, especially in Caucasians of Scandinavian heritage. Females are usually affected more often than males.

The disease typically begins between ages 20 and 40. Sarcoidosis is very rare in young children.

A person with a close blood relative who has sarcoidosis is nearly five times as likely to develop the condition.