Osteoarticular involvement in a series of 100 patients with sarcoidosis referred to rheumatology departments.

OBJECTIVE: To analyze the pattern of osteoarticular lesions in patients with sarcoidosis hospitalized in 4 rheumatology departments.
METHODS: We carried out a systematic retrospective analysis of cases with sarcoidosis admitted in the last 10 years, using hospital databases. Two distinct groups were defined from the outset: patients with Löfgren's syndrome (LS) or sarcoid rheumatism (SR). We assessed the following items: distribution of arthritis, chronicity, systemic manifestations, biochemical and immunological measures.
RESULTS: We included 100 patients (75% women); 43% had LS and 57% SR. Osteoarticular symptoms revealed the disease in 85% of patients. The patients in the LS group were younger than those in the SR group (41 +/- 9 vs 48 +/- 13 yrs; p < 0.006) and were more likely to have oligoarthritis involving ankles (58% vs 32%; p = 0.04) and high C-reactive protein concentrations (63% vs 33%; p < 0.005). Patients with SR presented osteoarticular symptoms in the form of oligoarthritis (32%), polyarthritis (32%), bony erosion in 8/57 (14%), and osteitis in 9/57 (16%). Lung interstitial involvement was more frequent in the SR group than in the LS group (38% vs 18%; p = 0.03). Chronic polyarthritis was associated with the detection of rheumatoid factor (p = 0.004). Osteitis occurred in older patients (p = 0.02).
CONCLUSION: SR was the most frequent manifestation leading to hospitalization; it was characterized by oligoarthritis and polyarthritis and associated with interstitial lung involvement. Osseous involvement occurred in a quarter of SR patients with similar frequency of erosions targeting the distal small bones and osteitis. These latter occurred at a later age.