Sarcoidosis: a rheumatologist's perspective

Sarcoidosis is a systemic disorder of unknown etiology, which may involve various tissues and organs and is characterized by a noncaseating granuloma reaction. While pathogenesis is not yet clear, cellular immune system activation and nonspecific inflammatory response occur secondarily to several genetic and environmental factors. T helper 1-cells and macrophage-derived pro-inflammatory cytokines stimulate the inflammatory cascade and formation of granuloma occurs as a result of tissue permeability, cell influx, and local cell proliferation. The different prevalence, clinical results, and disease course observed in different races and ethnic groups, is an indicator of the heterogeneous nature of the disease. Sarcoidosis may mimic and/or may occur concomitantly with numerous primary rheumatic diseases. This disease most commonly presents with bilateral hilar lymphadenopathy, pulmonary infiltrations, and skin and eye lesions. Locomotor system involvement is observed at a range of 15% and 25%. Two major joint involvements have been described: acute and chronic form. The most common form, the acute form, may be the first sign of sarcoidosis and present with arthralgia, arthritis, or periarthritis. Chronic sarcoid arthritis is usually associated with pulmonary parenchymal disease or other organ involvement and occurs rarely. While asymptomatic muscular involvement is reported between 25% and 75%, symptomatic muscular involvement is very rare. Symptomatic myopathy may present as th...
Source: Therapeutic Advances in Musculoskeletal Disease - Category: Orthopaedics Authors: Tags: Reviews Source Type: research