Arthritis as a feature of sarcoidosis occurs in 10–35% of patients. It is usually acute in onset, but articular symptoms may appear insidiously and antedate other manifestations of the disease. Knees and ankles are most commonly involved, but any joint can be affected. Distribution of joint involvement is usually polyarticular and symmetric. The arthritis is commonly self-limited, resolving after several weeks or months and rarely resulting in chronic arthritis, joint destruction, or significant deformity. Sarcoid arthropathy is often associated with erythema nodosum, but the diagnosis is contingent on the demonstration of other extra-articular manifestations of sarcoidosis and, notably, biopsy evidence of noncaseating granulomas. Despite the clinical appearance of an inflammatory arthritis, synovial fluid often is noninflammatory (ie, less than 2000 leukocytes/mcL [2.0 × 109/L]). In chronic arthritis, radiographs show typical changes in the bones of the extremities with intact cortex and cystic changes.
Treatment of arthritis in sarcoidosis is usually symptomatic. Patients with severe and progressive joint disease may respond to corticosteroids, methotrexate, or TNF inhibitors.
et al. Treatment of sarcoidosis in U.S. rheumatology practices: data from ACR's Rheumatology Informatics System for Effectiveness (RISE) registry. Arthritis Care Res (Hoboken). 2022;74:371.