Initial Workup and Treatment for Suspected Polymyalgia Rheumatica (PMR)
The initial workup for suspected polymyalgia rheumatica should include a comprehensive laboratory assessment to exclude mimicking conditions, followed by treatment with glucocorticoids at a dose of 12.5-25 mg prednisone equivalent daily. 1
Diagnostic Workup
Basic Laboratory Dataset
- Obtain rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies (ACPA) to exclude rheumatoid arthritis 1
- Measure inflammatory markers: C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR) - typically elevated in PMR 1
- Complete blood count to assess for other inflammatory or hematologic conditions 1
- Metabolic assessment: glucose, creatinine, liver function tests 1
- Bone profile including calcium and alkaline phosphatase 1
- Urinalysis to exclude renal pathology 1
Additional Recommended Tests
- Protein electrophoresis to exclude paraproteinemia 1
- Thyroid stimulating hormone (TSH) to rule out thyroid disorders 1
- Creatine kinase to exclude myopathy 1
- Vitamin D levels for baseline assessment prior to steroid therapy 1
Further Testing Based on Clinical Presentation
- Anti-nuclear antibodies (ANA) if systemic autoimmune disease is suspected 1
- Anti-neutrophil cytoplasmic antibodies (ANCA) if vasculitis is suspected 1
- Tuberculosis testing if considering immunosuppressive therapy 1
- Chest radiograph to exclude malignancy or other conditions 1, 2
Assessment of Comorbidities
- Evaluate for hypertension, diabetes, glucose intolerance, cardiovascular disease 1
- Screen for dyslipidemia, peptic ulcer disease, osteoporosis 1
- Check for cataracts or glaucoma risk factors 1
- Document history of chronic or recurrent infections 1
- Review current medications, especially NSAIDs 1
Treatment Approach
Initial Glucocorticoid Therapy
- Start with prednisone 12.5-25 mg daily 1
- Higher initial doses within this range for patients with high relapse risk and low adverse event risk 1
- Lower initial doses for patients with significant comorbidities 1
- Doses ≤7.5 mg/day are discouraged for initial treatment 1
- Expect clinical improvement within 7 days of starting therapy 3, 2
Monitoring Response
- Assess response to treatment within 4 weeks 4
- Response is typically defined as 70% improvement in PMR symptoms on visual analog scale 4
- Poor response to 20 mg/day prednisone should prompt consideration of alternative diagnoses 3, 5
Follow-up Schedule
- Every 4-8 weeks during the first year of treatment 1, 6
- Every 8-12 weeks during the second year 1
- More frequent monitoring during relapse or when tapering prednisone 1
Relapse Management
- For relapses on ≤5 mg prednisone, return to the previous effective dose 6
- After re-establishing control, taper more slowly than initially (≤1 mg/month) 6
- Consider methotrexate as a steroid-sparing agent for frequent relapses 6, 2
Special Considerations
- Consider specialist referral for atypical presentations (peripheral arthritis, systemic symptoms, low inflammatory markers, age <60 years) 1
- Refer patients with high risk of steroid-related side effects or refractory disease 1
- Female sex may be associated with higher risk of glucocorticoid side effects 1
- Risk factors for relapse include female sex, high ESR (>40 mm/hr), and peripheral inflammatory arthritis 1
- Provide patient education about PMR and individualized exercise programs 1
- Ensure osteoporosis prophylaxis for patients on long-term glucocorticoids 3