Polymyalgia Rheumatica

1
Polymyalgia Rheumatica

• Sarah Hughes, MD
• Morning Report
• January 24, 2006

2
Polymyalgia Rheumatica

• PMR is an inflammatory condition of unknown
  etiology
• Characterized by aching stiffness in the
  shoulder and pelvic girdles and the neck
• Occurs in people 50 yrs old
• Usually responds to low doses of steroids
• Is related to Giant Cell Arteritis, with
  biopsy-proven GCA present in about 4-21

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Epidemiology

• Prevalence of 1 case for every 133 people over 50
  yrs of age.
• Incidence increases with age, peaks 70-80yrs
• Females Males in all age groups (21)
• Higher incidence at higher lattitudes,
  Scandinavian countries
• Rarely reported in blacks, but appears to have
  the same presentation, course, and response to
  treatment.

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Diagnostic Criteria

• Criteria most frequently used for diagnostic
  purposes are empirical.
• Those of Hunder at Mayo clinic Healey at Mason
  clinic are most widely used.
• A current ongoing international project is aiming
  to develop new diagnostic and classification
  criteria and validate them.

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Diagnostic Criteria
Salvarani, C. Polymyalgia Rheumatica. Best
Practice Research Clinical Rheum. 2004. Vol.
18, No. 5, pp. 705-722.
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Etiology

• Probably polygenic in which multiple
  environmental and genetic factors influence
  susceptibility and severity.
• Possible infectious triggers
• Viruses adenovirus, RSV, parvovirus,
  parainfluenza
• Bacteria Mycoplasma, Chlamydia pneumoniae

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Etiology

• Genetic component probable
• HLA-DRB104 and -DRB101 appear to be most
  associated with susceptibility to PMR
• Genetic polymorphisms of additional genes
  involved in initiation and regulation of
  inflammatory reaction
• ICAM-1, TNF, IL-1 receptor antagonists
• Possible subclinical vasculitis

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Clinical Manifestations

• Persistent pain (for at least 1 month)
• Aching morning stiffness in neck, shoulder and
  pelvic girdles lasting 30 min.
• Discomfort is bilateral, worse w/ movement, and
  usually interferes w/ ADL
• Evidence of systemic involvement

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Clinical Manifestations

• Shoulder pain is presenting sign in 70-95
• Hips and neck 50-70
• Pain usually radiates distally towards elbows and
  knees
• Systemic signs seen in 1/3
• Fever
• Malaise/fatigue
• Anorexia, weight loss

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Clinical Manifestations

• Exam reveals little evidence of proximal joint
  swelling or tenderness
• MRI studies have shown subdeltoid subacromial
  bursitis are more prominent than actual joint
  synovitis

11
Clinical Manifestations
Cantini, F. Polymyalgia Rheumatica and Giant Cell
Arteritis. NEJM. 2002. Vol. 347, No. 4, pp.
261-271.
12
Clinical Manifestations

• Distal manifestations also seen in 1/2 cases
• Nonerosive, self-limiting, asymmetric peripheral
  arthritis (knee/wrist)
• Carpal tunnel syndrome
• Distal extremity swelling pitting edema over
  dorsum of hands and wrists, ankles and feet.

13
Clinical Manifestations
Cantini, F. Polymyalgia Rheumatica and Giant Cell
Arteritis. NEJM. 2002. Vol. 347, No. 4, pp.
261-271.
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Labs

• ESR 40mm/hr (nl in 7-20)
• CRP less influenced by other factors, may be more
  sensitive direct measure
• IL-6
• Modest anemia of chronic disease in 2/3
• Mildly abnormal LFTs in 1/3
• Rheum factor and ANA usually negative
• Muscle enzymes are normal

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Differential Diagnosis

• SLE
• Look for pleuritis or pericarditis
• Leukopenia or thrombocytopenia
• Check anti-dsDNA and anti-ENA antibodies
• RA
• Small joints of hands/feet
• Only partially responsive to steroids
• Considerable overlap b/t PMR seronegative RA

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Differential Diagnosis

• Polymyositis
• Symmetric proximal muscle weakness
• Pain not prominent
• Elevated CK, aldolase abnormal EMG, myositis on
  muscle biopsy
• Fibromyalgia
• Late-onset spondyloarthropathy

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Differential Diagnosis

• Malignancy
• Solid (kidney, ovary, stomach)
• Hematologic (myeloma, primary amyloidosis)
• Infection
• Bacterial endocarditis
• Lack of adequate response to prednisone and
  presence of atypical features should make one
  consider these

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Treatment Course

• Corticosteroids are drugs of choice (10-20mg/day)
• Trial of NSAIDs for 2-4 weeks if mild
• Complete or nearly complete resolution of sx is
  seen in a few days - absence of improvement
  should cause one to question diagnosis.
• Relapses do occur, more frequent in first 1-2
  years.

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Treatment Course

• Follow ESR or CRP
• Treatment for 1-2 years is often required,
  sometimes longer
• Watch for corticosteroid adverse effects!
• Methotrexate proposed as CS-sparing drug
• Infliximab
• Depot Methylprednisolone had similar efficacy
  fewer adverse effects

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Summary

• PMR is a common illness in certain populations
• Incidence increases after the age of 50 and peaks
  between 70-80 years of age.
• Biopsy-proven GCA has been observed in 4-21 of
  pts with PMR
• Arthroscopic, radioisotopic, and MRI studies
  indicate presence of synovitis in proximal joints
  and periarticular structures.

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Summary

• Distal manifestations are present in about half
  of the cases
• About 7-20 have normal ESR at diagnosis
• A course of treatment of 1-2 years is often
  required, with some patients having a more
  chronic, relapsing course.
• Overall mortality is not effected.

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References

• Bengtsson, B. Chapter 24 Polymyalgia Rheumatica.
  Primer on the Ruematologic Diseases. 1997.
  Arthritis Foundation. Pp 305-6.
• Cantini, F. Polymyalgia Rheumatica and Giant Cell
  Arteritis. NEJM. 2002. Vol. 347, No. 4, pp.
  261-271.
• Goodwin, JS. The very low prevalence of
  polymyalgia rheumatica in blaks may be an
  artifact. J Am Geriatrt Soc. 1990. Jul vol. 38,
  No. 7, pp. 824-6.
• Salvarani, C. Polymyalgia Rheumatica. Best
  Practice Research Clinical Rheumatology. 2004.
  Vol. 18, No.5, pp. 705-722.
• Sanford, RG. Polymyalgia rheumatica and temporal
  arteritis in blacks -- clinical features and HLA
  typing. J Rheumatology. 1977 Winter. Vol. 4, No.
  4, pp. 435-42.
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