Polymyalgia Rheumatica

Question 1

Epidemiology of PMR

Answer 1

-Three times more common than GCA but clinical overlap
=About 50% GCA have PMR
=About 15% PMR have GCA
-Peak incidence age 70-80
=Rare below the age of 50
-About 75% of patients are FEMALE
-Rapid onset (2 weeks)

Question 2

Pathophysiology of PMR

Answer 2

-Less well understood than GCA
-Genetic predisposition
=HLA Class II region
-Overlap with GCA in those with vasculitis
-Increased Th17 cells in blood
-Inflammatory infiltrate in synovium and tendon sheaths

Question 3

Diagnosis of PMR

Answer 3

-Proximal symmetrical muscle pain worse with movement affecting shoulder (may radiate to elbows) and pelvic girdle (morning stiffness and inflammatory pain >45 minutes)
=Acute onset
=Difficulty rising from chair unaided and lifting arms up to comb hair
=Carpal tunnel syndrome, peripheral arthritis (asymmetrical), swelling with pitting oedema
-General malaise, lethargy, depression, low-grade fever, anorexia, night sweats, mild polyarthralgia

-Raised ESR> 40 (and CRP)
-Mild anaemia
-Autoantibodies negative
-Muscle enzymes normal
-Resolution of symptoms with steroids in 3-4 days
-Ultrasound= subdeltoid bursitis, bicipital tenosynovitis, glenohumeral synovitis, hip synovitis

Question 4

Management of PMR

Answer 4

-Prednisolone 15-20mg /day, response within 2-3 days
-Reduce dose by 2.5mg/month
-When at 10mg, reduce dose by 1mg/month (1-2 years)
-Steroid sparing medicines
=Methotrexate, azathioprine
-Osteoporosis prophylaxis (calcium, vit D, bisphosphonate)

Question 5

Indications for rheumatology referral

Answer 5

-Patient fails to respond adequately to corticosteroid therapy (suggests the diagnosis is wrong).
-Symptoms cannot be controlled with less than 10mg prednisolone daily (for consideration of immunosuppressives)