Key features of polymyalgia rheumatica mimics
Disease | Features |
---|---|
Inflammatory diseases | |
Rheumatoid arthritis | Symmetrical joint involvement, autoantibody-positive, may see erosions on imaging in advanced disease |
Spondyloarthritis | Low back involvement, sacroiliac joint tenderness, sacroiliitis on imaging |
RS3PE (remitting seronegative symmetrical synovitis with pitting edema) | Peripheral edema, extensor synovitis on imaging, may be paraneoplastic |
Crystalline arthropathy | Usually involvement of medium to large joints, intermittent symptoms, characteristic radiography and ultrasonographic findings, synovial fluid analysis positive for crystals |
Autoimmune myositis | Muscle weakness and tenderness, elevated muscle enzymes |
Other connective tissue diseases | Multiorgan involvement, specific autoantibodies may be positive, hypocomplementemia |
Noninflammatory diseases | |
Osteoarthritis | Pain exacerbated with use, normal inflammatory markers, degenerative changes on imaging |
Fibromyalgia | Fatigue, chronic pain with more generalized involvement |
Spinal spondylosis and stenosis | Numbness, paresthesias, muscle weakness, normal inflammatory markers |
Parkinson disease | Muscle stiffness primary complaint, other symptoms typical of Parkinson disease including tremor and rigidity |
Infection | Fever, heart murmur, leukocytosis, positive blood cultures |
Malignancy and paraneoplastic syndromes | Weight loss, diffuse symptoms usually not limited to shoulder or pelvic girdle, lack of response to low-dose glucocorticoid therapy |
Drug-induced myopathy (eg, statin, glucocorticoid, colchicine) | Lack of systemic symptoms, muscle weakness and tenderness, improvement with discontinuation of drug, elevated muscle enzymes, positive anti-HMG-CoA reductase antibody |
Thyroid and parathyroid disease | Systemic symptoms typical of endocrinopathy; abnormal thyroid markers; abnormal calcium, phosphorus, or parathyroid levels |