What are the diagnostic criteria and treatment options for an adult over 50 years old presenting with widespread muscle aches and stiffness, particularly in the shoulders, hips, and neck, suspected of having polymyalgia rheumatica (PMR)?

Polymyalgia Rheumatica Diagnosis

Diagnose PMR in adults over 50 with bilateral shoulder and hip girdle pain plus morning stiffness lasting >45 minutes, elevated ESR/CRP, and exclusion of mimicking conditions through targeted laboratory testing, then confirm with rapid response to prednisone 12.5-25 mg daily. 1, 2, 3

Clinical Diagnostic Criteria

Age and symptom requirements:

• Patient must be >50 years old (atypical if <60 years, warranting specialist referral) 1, 2
• Bilateral shoulder pain with or without hip/pelvic girdle involvement 2, 3
• Morning stiffness >45 minutes with functional impairment 3, 4
• Acute or subacute onset over days to weeks 4

Key clinical pitfall: Pelvic girdle involvement is NOT mandatory for diagnosis—some patients present with isolated shoulder symptoms 2

Essential Laboratory Workup

Core inflammatory markers (obtain first):

• ESR and/or CRP—typically elevated, though normal values can occur in atypical presentations 2, 3, 5
• ESR >40 mm/hr predicts higher relapse rates and need for prolonged therapy 3, 5

Mandatory exclusion tests:

• Rheumatoid factor and/or anti-CCP antibodies (exclude rheumatoid arthritis) 2, 3
• Complete blood count (assess for other inflammatory causes/anemia) 3
• Creatine kinase—must be normal in PMR (elevated suggests inflammatory myositis instead) 3
• Glucose, creatinine, liver function tests (baseline before glucocorticoid therapy) 3
• Bone profile including calcium and alkaline phosphatase 3
• Urinalysis 3

Additional tests based on clinical suspicion:

• Protein electrophoresis (exclude paraproteinemia) 3
• TSH (exclude thyroid disorders) 3
• ANA and ANCA (if other autoimmune conditions suspected) 3
• Chest radiograph (exclude malignancy) 3

Diagnostic Algorithm

Step 1: Clinical screening

• Bilateral shoulder pain + morning stiffness + age >50 + functional impairment → Proceed to Step 2 3

Step 2: Laboratory confirmation

• Obtain core laboratory tests listed above 2, 3
• Elevated ESR/CRP + normal CK + negative RF/anti-CCP → Proceed to Step 3 3

Step 3: Therapeutic trial

• Initiate prednisone 12.5-25 mg daily 1, 2, 3
• Rapid response (within days to 1-2 weeks) supports diagnosis but is not pathognomonic 6
• Lack of response warrants reconsideration of diagnosis 1

Conditions Requiring Specialist Referral

Atypical presentations mandating rheumatology consultation: 1, 2

• Peripheral inflammatory arthritis
• Systemic symptoms beyond typical PMR
• Normal inflammatory markers despite classic symptoms
• Age <60 years
• High risk of glucocorticoid-related side effects
• Refractory to initial glucocorticoid therapy

Treatment Initiation

Initial glucocorticoid dosing:

• Start prednisone 12.5-25 mg daily (oral, single morning dose) 1, 2, 3
• Higher doses (20-25 mg) for: high ESR >40, female sex, peripheral arthritis, low adverse event risk 3
• Lower doses (12.5-15 mg) for: diabetes, osteoporosis, glaucoma, other comorbidities 1
• Strongly avoid initial doses ≤7.5 mg/day or >30 mg/day 1

Alternative route:

• Intramuscular methylprednisolone 120 mg every 3 weeks may be considered as alternative to oral therapy 1

Tapering schedule: 1

• Weeks 0-8: Taper to 10 mg/day prednisone
• Below 10 mg: Reduce by 1 mg every 4 weeks until discontinuation
• If relapse occurs: Increase to pre-relapse dose, then taper over 4-8 weeks back to relapse dose

Baseline Comorbidity Assessment Before Starting Glucocorticoids

Screen for: 3

• Hypertension, diabetes/glucose intolerance, cardiovascular disease
• Dyslipidemia, peptic ulcer disease
• Osteoporosis risk (consider DEXA scan and calcium/vitamin D supplementation)
• Glaucoma and cataracts

Special consideration: Female patients have higher risk of both glucocorticoid side effects and disease relapse 3

Monitoring Schedule

Follow-up frequency: 1, 3

• Every 4-8 weeks during first year
• Every 8-12 weeks during second year
• As indicated for relapses or during tapering

At each visit monitor: 1, 3

• Clinical symptoms (pain, stiffness, functional status)
• ESR/CRP (though values suppressed by glucocorticoids during treatment) 5
• Glucose and complete blood count
• Evidence of glucocorticoid side effects
• Base treatment adjustments primarily on clinical symptoms rather than ESR alone during treatment phase 5

Glucocorticoid-Sparing Agents

Consider methotrexate for: 1, 7

• Relapsing disease
• Prolonged therapy requirements
• High risk of glucocorticoid toxicity
• Inability to taper below 7.5-10 mg prednisone

Emerging biologics: 7

• Tocilizumab and sarilumab (anti-IL-6 receptor agents) show efficacy in reducing relapses and cumulative glucocorticoid burden
• Reserved for refractory cases or high-risk patients

Critical Pitfalls to Avoid

• Do not use response to steroids as the sole diagnostic criterion—many conditions respond to glucocorticoids 6
• Do not ignore normal inflammatory markers in otherwise classic presentations—this warrants specialist evaluation 2, 5
• Do not confuse pain-related functional limitation with true muscle weakness—weakness suggests myositis, not PMR 2, 3
• Do not overlook immune checkpoint inhibitor therapy as potential cause of PMR-like syndrome in cancer patients 2, 4
• Do not forget to screen for giant cell arteritis—occurs in 10-20% of PMR patients and requires higher glucocorticoid doses 4, 8