Incidence and clinical picture of sarcoidosis in a circumscribed geographical area.

The incidence and clinical picture of sarcoidosis were studied on the basis of an unselected series of 354 sarcoidosis patients (168 men, 186 women) in a defined geographical area during the years 1970-81. All the patients were examined in hospital. The mean annual incidence of sarcoidosis was 15 cases per 100 000 population 15 years or older. Sixty-four per cent of the cases began or were diagnosed in the first half of the year (P less than 0.001). The disease was diagnosed in 67% of the male cases and 38% of the females before the age of 35. Sarcoidosis was found by mass chest radiographic survey or by chance in 99 men (59%) and 103 women (55%), but 85 men (51%) and 129 women (69%) had symptoms of the disease. Two hundred and eighteen patients (62%) had bilateral hilar adenopathy upon diagnosis of the disease, 120 (34%) parenchymal changes and three fibrotic radiographic changes. Lung function test results tended to decrease with the radiographic stage and were indicative more of obstruction than restriction.