Sarcoidosis

Sarcoidosis is a chronic, multisystem disorder of unknown cause characterized in affected organs by an accumulation of T lymphocytes and mononuclear phagocytes, noncaseating epithelioid granulomas, and derangements of the normal tissue architecture.

The cause of sarcoidosis is unknown. Various infectious and noninfectious agents have been implicated, but there is no proof that any specific agent is responsible.

Sarcoidosis is a relatively common disease affecting individuals of both sexes and almost all ages, races, and geographic locations. Females appear to be slightly more susceptible than males.

Sarcoidosis is occasionally discovered in a completely asymptomatic individual, but more commonly it presents abruptly over 1 to 2 weeks or the affected individual develops symptoms insidiously over several months. Despite the fact that sarcoidosis is a systemic disease and some evidence of inflammation can be detected in most organs in the majority of patients, sarcoidosis is important clinically because of the pulmonary abnormalities and, to a lesser extent, lymph node, skin, liver, and eye involvement

For a typical case, the diagnosis of sarcoidosis is made by a combination of clinical, radiographic, and histologic findings. The presence of skin anergy is typical but not diagnostic of sarcoidosis. Individuals with sarcoidosis who develop active tuberculosis react strongly to skin tests with purified protein derivative.

Overall, the prognosis in sarcoidosis is good. Most individuals who present with the acute disease are left with no significant sequelae. The therapy of choice for sarcoidosis is glucocorticoids.

Various other drugs have been tried, including indomethacin, oxyphenbutazone, chloroquine, hydroxychloroquine, methotrexate, p-aminobenzoate, allopurinol, levamisole, azothioprine, and cyclophosphamide; but there is no evidence, apart from anecdotal, uncontrolled reports, to support their efficacy. Cyclosporine is ineffective for the pulmonary manifestations of the disease; anecdotal reports suggest that it may be useful in extrathoracic sarcoid not responding to glucocorticoids.