| Sarcoidosis is an unusual multisystem granulomatous disorder of unknown etiology, most commonly affecting young adults and presenting most frequently with bilateral hilar lymphadenopathy, pulmonary infiltration, and skin or eye lesions. Over the past 50 years a number of potential etiologic agents have been examined including bacteria, viruses, certain occupational and environmental exposures, and histocompatibility complexes; but no direct, consistent causality has been identified. Initially, this study assesses the geographic distribution of sarcoidosis in South Carolina by using modified county hospitalization rates as determined from hospital discharge records. Hospitalization rates are 6 times higher for African-Americans than Caucasians. Both racial groups demonstrate higher rates of the disease in the coastal region of the State. African-American rates consistently decrease with increasing distance from the Atlantic coastline. Geographic variation in the disease is not associated with education level, income level, poverty status, physician density, or diagnostic variability at the population level. Only general hospital usage was significantly associated with the variability in sarcoidosis rates in this study. Secondly, using standard case-control methodology, this work did not find the overall length of time spent residing or working in South Carolina to be associated with the development of sarcoidosis. Additionally, neither the location of residence nor employment with respect to physiographic regions appears to be associated with the development of the disease. Sarcoidosis patients were, however, 8 times more likely than controls to have at least one relative with the disease, 3.7 times more likely to have used wood stoves prior to disease development, and 6.8 times more likely to have used fireplaces prior to disease development. Sarcoidosis subjects also exhibited higher levels of use of both wood stoves and fireplaces than controls. This works identifies two rural-based risk factors involving the handling and burning of wood which may, in part, explain the higher rates of sarcoidosis found in southeastern, rural communities in the US. |
