Familial Sarcoidosis

Abstract
Generalized sarcoidosis is becoming recognized as a common disease, but its etiology remains unknown. For years, tuberculosis was considered the most likely underlying cause; however, as time has passed, it has become recognized as a probable complication rather than a cause.1Specific agents such as helminths,2beryllium,3,4histoplasma,5,6cryptococci,7and foreign bodies8,9have been associated with isolated cases, but by no means can they account for the pathogenesis in the vast majority of involved patients. Recently, environmental influences have been considered as a potential etiologic factor. This idea evolved from the work by Michael et al.,10who, in 1950, reviewed 226 cases from military personnel, and discovered that most were born in rural areas of the southern section of the United States. In 1955, Gentry, Nitowsky and Michael11published an extensive survey of 297 veterans showing that the birthplace and residence when inducted into the service correlated with an