[Recent epidemiological features of sarcoidosis in Japan].

The 8th nation-wide epidemiological survey on sarcoidosis in Japan was carried out in 1991. Total number of sarcoidosis patients was increased two times more than that of the 7th survey which was carried out in 1984. Moreover, the epidemiological features of the disease were different, at least in part, from those of the previous survey, especially on the age distribution and the frequency of cases with symptoms. These differences might be depend on the changes of the diagnostic methods including the reduction of systemic mass radiography.