Clinical characteristics of patients with remitting seronegative symmetrical synovitis with pitting edema compared to patients with pure polymyalgia rheumatica.

Objective: To compare clinical features of patients with remitting seronegative symmetrical synovitis with pitting edema (RS3PE) and patients with polymyalgia rheumatica (PMR) and to explore the purported association between RS3PE and malignancy.

Methods: We did a retrospective chart review of patients with RS3PE and PMR treated in a community-based hospital between January 2000 and December 2009. Outcomes assessed were clinical course of disease and associated malignancies.

Results: We identified 28 patients with RS3PE and 123 with pure PMR. All patients with RS3PE fulfilled PMR criteria as well. Age, comorbidity, erythrocyte sedimentation rate, duration and progression of symptoms, treatment response to initial low-dose steroids, and steroid complication rates were similar in both groups. Patients with RS3PE were more likely to be male (79% vs 41%; p = 0.001) and to have a history of smoking (39% vs 15%; p = 0.008) and a higher rate of depression (11% vs 2%; p = 0.044) at diagnosis. Among those with RS3PE, hip pain was less common (39% vs 74%; p = 0.001) than in the PMR group. No patients with RS3PE and 6 patients with pure PMR (4.9%) developed another rheumatological disease during followup. Seven of 9 patients (78%) with concurrent cancer presented slightly more frequently with systemic symptoms compared to patients without cancer (48%; p = 0.098), especially with fatigue (56% vs 22%; p = 0.037) and anorexia (33% vs 9.0%; p = 0.047). Despite rigorous cancer screening in patients with RS3PE, however, the rate of associated malignancy was not statistically different from that of patients with pure PMR [2 (7%) vs 7 (6%), respectively; p = 0.673].

Conclusion: Despite evidence that RS3PE is clinically distinct from PMR, we observed characteristics, treatment response, and outcomes like those expected in pure PMR. Compared to patients with pure PMR, patients with RS3PE are more likely to be male, to be depressed, and to smoke. Contrary to earlier studies, no clear association of RS3PE with malignancy was found despite rigorous cancer screening, although clinicians should be aware that patients with concurrent cancer may manifest more systemic signs and symptoms, as well as steroid resistance.