Sarcoidosis

Sarcoidosis is a diagnosis of exclusion of granulomatous lung diseases, including tuberculosis and histoplasmosis.

Typical history and biopsy from affected organs are essential for the diagnosis.

Treated with topical corticosteroids for mild local cutaneous disease. Systemic corticosteroids are the mainstay of treatment for severe disease.

Carries a mortality of 1% to 6%.

Poorer prognosis if black ancestry, chronic pulmonary involvement, lupus pernio, or chronic hypercalcaemia.

Spontaneous remissions occur in 55% to 90% of patients with stage I, 40% to 70% of patients with stage II, and about 20% of patients with stage III disease, but no remissions are expected in stage IV.

Sarcoidosis is a chronic granulomatous disorder of unknown aetiology, commonly affecting the lungs, skin, and eyes. It is characterised by accumulation of lymphocytes and macrophages and the formation of non-caseating granulomas in the lungs and other organs. Although lungs and lymph nodes are involved in more than 90% of patients, virtually any organ can be involved. It has a bimodal age distribution with 2 peaks in the third and fifth decades. The clinical course is often heterogeneous and unpredictable.