The epidemiology of sarcoidosis.

The nationality, social factors, exposures, morbidity, mortality, and hospital discharge notes have been analysed in a series of patients with histologically proven sarcoidosis, and correlated with clinical and radiological features. Compared with the expected prevalence according to the Central London population obtained from the 1961 Census, Irish and West Indians attended the Sarcoidosis Clinic twice as frequently as British, whereas African Negroes are under-represented. Sarcoidosis is slightly commoner in women, particularly those in the childbearing years of life. Mass miniature radiography rates per 100,000 population reveal prevalence rates of twenty overall, forty-three in those aged 25-34 years, and ten in those aged over 45 years. Erythema nodosum, other skin lesions, and ocular involvement occurred twice as often in women. The death-rate of about 1·7/10 population is slightly higher in women and in those living in rural districts. Hospital discharge rates are about three per 100,000 people at risk each year.