Sarcoidosis a systemic disease of young adults with an unknown etiology, inconsistent manifestations, and an unpredictable course. Sarcoidosis affects both sexes, all races, and all ages throughout the world. In the United States and Europe, the prevalence is between 10 and 40 per 100,000. This disease tends to appear in young adults between the ages of twenty and forty. US blacks are affected by this disease ten to seventeen times as often as whites are.
Women seem to be affected slightly more often than men.
Nonsmokers are affected more than smokers. Studies are not definitive, but both genetic and environmental factors seem to be involved in development of the disease. Monozygotic twins are more likely to both be affected than dizygotes in some cases which suggests a genetic etiology. No link to HLA antigens have been proven. Sarcoidosis causes damage by the derangement of normal tissue architecture through space occupation rather than by the release of any mediators or exotoxins.