Polymyalgia rheumatica

Inflammatory rheumatic syndrome of older adults (age >50) causing bilateral shoulder and hip girdle pain and morning stiffness without true muscle weakness. It is associated with markedly elevated inflammatory markers and typically responds dramatically to low-dose corticosteroids.

• Common in older adults (~2% lifetime risk) and second only to rheumatoid arthritis as a cause of inflammatory rheumatic disease in the elderly. Causes significant pain and disability but is very treatable with steroids. Crucially, ~15% of PMR patients develop giant cell arteritis, a vasculitis that can cause blindness if not promptly recognized and treated.

• Typical patient is >50 (often ~70s) with subacute onset of bilateral shoulder and hip pain accompanied by pronounced morning stiffness (lasting >30–60 minutes). Patients often report difficulty with overhead activities (e.g. combing hair, putting on a coat) and getting out of a chair.
• Systemic symptoms are common: low-grade fever, fatigue, loss of appetite, and weight loss can occur. On exam, range of motion in shoulders and hips is limited by pain, but muscle strength is normal (pain may make strength exam difficult). Muscle tenderness is usually absent or mild.
• Labs: ↑ ESR and ↑ CRP (often very high, e.g. ESR >50 mm/h) are characteristic. Importantly, CK is normal (helps distinguish from polymyositis). Rheumatoid factor and CCP are typically negative, and there are no erosive changes on imaging (helping exclude rheumatoid arthritis).
• Variations: some patients have mild peripheral arthritis or hand edema (e.g. RS3PE syndrome) in addition to the shoulder/hip girdle symptoms. ~40–50% of patients with giant cell arteritis (temporal arteritis) also have PMR symptoms, so there can be overlap; PMR without cranial symptoms is often called "isolated" PMR.

1. Confirm inflammation: check ESR and CRP (nearly always elevated in PMR—if normal, question the diagnosis).
2. Exclude mimics: obtain a CK level (normal in PMR; elevated suggests myositis) and TSH (to rule out hypothyroid myopathy). Test RF and anti-CCP antibodies; positive results or significant joint swelling point to rheumatoid arthritis instead of PMR.
3. Consider imaging if doubt: ultrasound of shoulders can reveal bilateral subacromial/subdeltoid bursitis or biceps tenosynovitis typical of PMR. If giant cell arteritis is suspected (e.g. limb claudication or fever of unknown origin), vascular imaging (ultrasound or PET) can detect large-vessel involvement.
4. Therapeutic trial: a prompt, dramatic improvement (within 2–3 days) upon starting low-dose prednisone (10–20 mg daily) strongly supports the diagnosis of PMR.

1. Glucocorticoids are first-line: start low-dose prednisone (~15 mg daily). Symptoms usually improve within days. Continue for ~1–2 years while tapering slowly (reduce ~1 mg/month) to minimize relapse. Supplement calcium & vitamin D and consider bisphosphonates for bone protection during long-term steroids.
2. If unable to taper steroids or frequent relapses: add methotrexate as a steroid-sparing agent (2015 guidelines suggest early MTX in some cases). For refractory PMR, consider IL-6 inhibitor therapy (e.g., tocilizumab off-label; sarilumab was FDA-approved for PMR in 2023).
3. Regular exercise and physical therapy can help maintain muscle strength and function during treatment. NSAIDs are generally not sufficient alone and are not first-line due to limited benefit.

• Rapid steroid response: PMR pain and stiffness often improve within 48 hours of low-dose prednisone—a near-diagnostic clue.
• PMR causes stiffness & pain, but no weakness. By contrast, polymyositis causes true muscle weakness (and elevated CK).
• Always assess for new temporal headache, jaw pain, or vision changes in PMR patients—these red-flag symptoms herald giant cell arteritis.

• Giant cell arteritis symptoms (new headache, scalp tenderness, jaw claudication, visual disturbances) → requires urgent high-dose steroids to prevent vision loss.
• Poor or no improvement on moderate-dose prednisone → re-evaluate diagnosis. PMR should respond to steroids; lack of response suggests an alternate diagnosis (e.g. malignancy, infection, or a different rheumatic disease).

1. Age >50 with bilateral shoulder & hip girdle pain/stiffness + ↑inflammatory markers → suspect PMR.
2. Rule out other causes: check TSH, CK, and rheumatoid serologies (exclude hypothyroidism, polymyositis, RA).
3. If likely PMR, initiate low-dose prednisone (10–20 mg/day). Rapid symptom relief (within 2–3 days) essentially confirms PMR.
4. Taper prednisone gradually over 1–2 years (decrease ~1 mg/month once at 10 mg); monitor for relapse or return of symptoms at each taper step.
5. Educate patient about signs of temporal arteritis (headache, jaw claudication, vision changes); if these occur → start high-dose steroids immediately (suspected GCA).

• 70-year-old with bilateral shoulder and hip girdle aching, morning stiffness >1 hour, and ESR of 85 mm/hr → Polymyalgia rheumatica (classic presentation; treat with low-dose prednisone).
• Elderly patient on chronic low-dose steroids for PMR who develops new unilateral headache and jaw claudication → giant cell arteritis (temporal arteritis requiring high-dose steroids).