Prevalence, Incidence and Modes of Presentation

There are several reasons why it is difficult to ascertain the number of cases of sarcoidosis in a community. One of these is that since many cases are discovered at screening examinations and follow an asymptomatic course to resolution, it is certain that in the general community many individuals must pass through the whole course of the disease without consulting a doctor. Another is that clinical diagnosis is in some cases a matter of judgement, and it cannot be assumed that standards of diagnosis are uniform. Even death notifications are difficult to interpret, since most of the deaths which result, wholly or in part, from sarcoidosis occur many years after the active stage of the disease, at which time there may be little that is specific in the clinical picture; and thus it is probable that at least some deaths from the late results of sarcoidosis are notified under some other diagnostic label. And finally, the clinical manifestations of sarcoidosis are so various that a patient may come under medical care in various ways.