Epidemiology of sarcoidosis in the Isle of Man--1: A case controlled study.

A case controlled study of 96 cases of sarcoidosis has been carried out in the Isle of Man. Age and sex matched controls were selected at random from the pathology and radiology records, which cover 85% of the resident population, and a second control group was drawn from a tuberculosis register. Special efforts were made to achieve a high level of ascertainment. In this study most cases occurred in young adults. It affected the sexes equally and occurred more frequently in the indigenous Manx population. Thirty eight cases (39.6%) had been in contact with the disease before diagnosis, compared with two (1.2%) of the combined controls. These contacts included members of the same household, colleagues at work, and close friends. A bias may have been introduced as patients would inevitably be more aware of the disease and be more likely to mention previous contact than the controls. Nevertheless, the evidence is considered to support the view that sarcoidosis is a communicable disease.