KISS: Polymyalgia Rheumatica

Lancet October 2023 & BSR 2010

Diagnosis/Assessment:

• Suspect PMR if > 50 years old (although most >60) with ≥ 2 weeks of core symptoms:
  • Bilateral shoulder and/or pelvic girdle pain & stiffness AND
  • Stiffness lasting >45 minutes after waking or periods of rest.
• Additional systemic symptoms may be present (in 40-50%) - low-grade fever, fatigue, weight loss, anorexia, depression.
• Exclude/consider other conditions that can ‘mimic’ or be associated with PMR:
  • Giant cell arteritis - present in 15-20% with PMR; consider if more prominent systemic features or very high ESR/CRP.
  • Infections - consider viral, osteomyelitis, TB, infective endocarditis.
  • Cancer - myeloma, leukaemia, lymphoma, lung carcinoma; consider if more significant systemic symptoms or more widespread (i.e. not predominantly proximal) pain.
  • Endocrine disease - thyroid or parathyroid disease.
  • Other inflammatory diseases - RA, SLE, spondyloarthropathy.
  • Degenerative conditions - OA or bilateral impingement/frozen shoulder; usually mechanical pain (i.e. worse with activity) rather than inflammatory pain (improves with activity) and normal ESR/CRP.
  • Others - myositis/myalgia from statins, osteomalacia, fibromyalgia, CFS.
• Investigations to be done before starting corticosteroids:
  • In all cases - FBC, ESR/CRP, U&E, LFT, Ca, CK, TSH, protein electrophoresis, rheumatoid factor, dip urine.
  • Consider (depending on clinical features) - ANA, anti-CCP antibodies, CXR, and urine BJP.
• If PMR is the most likely diagnosis give a trial of treatment:
  • Prednisolone 15mg daily and review at 1 week - expect ≥ 70% improvement in symptoms within 1 week (typically many symptoms resolve within 24-72 hours).
  • If lesser response, consider increasing dose to 20mg, but if response still <70% refer.
• PMR diagnosis can be confirmed if core symptoms present, other ‘mimic’ conditions excluded and there is a typical response to oral corticosteroids; ESR/CRP are typically raised but a diagnosis can be made if normal (but these patients need referring, see below).
• Refer if atypical features of PMR/concern about alternative diagnosis:
  • Red flags e.g. weight loss, night pain, neurological features.
  • Younger than 60 years old or chronic onset of symptoms.
  • Normal inflammatory markers or ESR >100 +/- very high CRP.
  • <70% symptom response to 15-20mg prednisolone daily.

Ongoing Management:

• Flexible approach, individually tailored, most will need 1-2 years of treatment; 
  • Consider referral if unable to reduce doses at reasonable intervals, possible relapse or on steroids > 2 years.
• Suggested prednisolone regimen (remember to give blue steroid card/warn of risks):
  • 15mg OD 3 weeks, then 12.5 mg OD 3 weeks, then 10mg for 4-6 weeks.
  • Thereafter reduce by 1mg every 4-8 weeks.
• Bone protection (updated NOGG guidance 2021):
  • People on ≥7.5 mg prednisolone for ≥3 months are considered very high risk of fractures and should be considered for urgent specialist review, but start bisphosphonate in the meantime. 
  • For all others assess risk with FRAX (click here)
  • However, bone loss can occur early in steroid treatment so if DEXA is recommended (as it will in most cases) bisphosphonates should be started whilst awaiting DEXA scan if:
    • Woman aged >70, previous fragility fracture, FRAX score exceeding intervention threshold. 
• Monitoring - Review 1 week after dose changes and at least every 3 months in 1st year, or urgently if they develop symptoms of GCA.
• Patient information - NHS Patient information sheet and Versus Arthritis