Ddx | ||
---|---|---|
Clinical features | Diagnosis | |
Fibromyalgia | Young to middle-aged womenChronic widespread pain Fatigue, impaired concentration Tenderness at trigger points (eg, mid trapezius, costochondral junction) |
>3 months of symptoms with widespread pain index or symptom severity score Normal laboratory studies |
Polymyositis | Proximal muscle weakness (eg, increasing difficulty climbing up stairs) Pain mild/absent |
Elevated muscle enzymes (eg, creatine kinase, aldolase, AST) Autoantibodies (ANA, anti-Jo-1) Biopsy: Endomysial infiltrate, patchy necrosis |
Polymyalgia rheumatica | Age >50 Systemic signs & symptoms Stiffness > pain in shoulders, hip girdle, neck Association with giant cell (temporal) arteritis |
Elevated ESR, C-reactive protein Rapid improvement with glucocorticoids |