What is the workup and management for a patient presenting with symptoms of polymyalgia rheumatica (PMR)?

Polymyalgia Rheumatica: Workup and Management

The diagnosis and management of polymyalgia rheumatica (PMR) requires a specific laboratory workup, exclusion of mimicking conditions, and treatment with glucocorticoids at an initial dose of 12.5-25 mg prednisone daily with a structured tapering schedule over 1-2 years. 1

Clinical Presentation and Diagnosis

PMR typically presents with:

• Bilateral proximal muscle pain and morning stiffness affecting:
  • Neck
  • Shoulders and upper arms
  • Lower back, hips, and thighs
• Constitutional symptoms (fatigue, low-grade fever, weight loss)
• Acute onset over days to weeks
• Affects patients >50 years (peak incidence 70-75 years)
• More common in women (2-3 times) 2, 3

Diagnostic Workup

Required Laboratory Tests

• Inflammatory markers: ESR and/or CRP (typically markedly elevated)
• Rheumatoid factor and/or anti-CCP antibodies (to exclude RA)
• Complete blood count
• Metabolic panel: glucose, creatinine, liver function tests
• Bone profile: calcium, alkaline phosphatase
• Urinalysis 1

Additional Recommended Tests

• Protein electrophoresis
• Thyroid stimulating hormone (TSH)
• Creatine kinase (to exclude myopathy)
• Vitamin D level 1

Further Testing Based on Clinical Presentation

• ANA, ANCA (if other autoimmune conditions suspected)
• Tuberculosis testing (if relevant)
• Chest radiograph (to exclude malignancy or other conditions)
• Ultrasound of shoulders and hips (can show bursitis, synovitis) 1, 2

Differential Diagnosis

Critical to exclude conditions that mimic PMR:

• Rheumatologic conditions: Elderly-onset rheumatoid arthritis, seronegative spondyloarthropathies
• Malignancies: Solid tumors and hematologic malignancies (particularly concerning if poor response to steroids)
• Endocrine disorders: Thyroid disease
• Infections: Chronic infections
• Neurologic conditions: Parkinson's disease, polymyositis
• Drug-induced myalgia 1, 4

Management

Initial Treatment

• Glucocorticoid therapy:
  • Initial dose: 12.5-25 mg prednisone equivalent daily
  • Higher initial dose (within range) for patients with high relapse risk and low adverse event risk
  • Lower initial dose for patients with comorbidities (diabetes, osteoporosis)
  • Avoid NSAIDs as primary treatment 1, 5

Tapering Schedule

• Reduce to 10 mg/day within 4-8 weeks
• Then decrease by 1 mg every 4 weeks until discontinuation
• Total treatment duration typically 1-2 years
• Monitor for relapses during tapering 1, 5

Monitoring

• Follow-up visits:
  • Every 4-8 weeks in first year
  • Every 8-12 weeks in second year
  • As needed for relapses or during tapering
• Monitor for:
  • Disease activity (symptoms, inflammatory markers)
  • Steroid-related side effects
  • Comorbidities
  • Risk factors for relapse 1

Management of Refractory Cases

• Methotrexate: Consider at 7.5-10 mg/week for patients with:
  • Insufficient response to glucocorticoids
  • High risk of steroid-related adverse effects
  • Frequent relapses 5, 3

Special Considerations

Indications for Specialist Referral

• Atypical presentation (peripheral arthritis, systemic symptoms, low inflammatory markers, age <60)
• High risk of or experiencing steroid-related side effects
• PMR refractory to glucocorticoid therapy
• Frequent relapses or need for prolonged therapy
• Suspected giant cell arteritis (GCA) 1

Risk Factors for Relapse/Prolonged Therapy

• Female sex
• High ESR (>40 mm/hr)
• Peripheral inflammatory arthritis 1

Patient Education and Support

• Provide education about PMR and treatment
• Discuss potential steroid side effects and monitoring
• Advise on individually tailored exercise programs
• Ensure rapid access to healthcare providers for flares or adverse events 1

Complications and Comorbidities

• Giant Cell Arteritis: 15-30% of PMR patients may develop GCA
• Glucocorticoid-related adverse effects:
  • Diabetes/glucose intolerance
  • Hypertension
  • Osteoporosis
  • Cataracts/glaucoma
  • Weight gain
  • Skin thinning
  • Increased infection risk 1, 2, 3

Proper diagnosis, appropriate initial dosing of glucocorticoids, careful monitoring, and structured tapering are essential for optimal management of PMR to reduce morbidity and improve quality of life.