PMR is a clinical syndrome characterized by severe aching and stiffness in the neck, shoulder girdle, and pelvic girdle.
closely linked to temporal arteritis (giant cell arteritis)
25% of patients with PMR experience temporal arteritis, and if this is present there is a risk of damage to the arteries of the eye which can rapidly lead to blindness.
50% of patients with temporal arteritis will have PMR at the same time.
mainly a condition of those older than 50 years in whom it affects 1 in 200, but particularly females (M:F ratio 1:2), aged over 70 years.
clinical features
pain and aching of proximal muscle groups (hip/pelvis/shoulders/neck in particular), usually worse in the morning or after inactivity and of relatively abrupt onset
non-specific clinical findings
general constitutional symptoms of malaise, fatigue, low grade fevers, weight loss
normal creatinine kinase level (thus excludes myositis)
negative finding for rheumatoid factor (thus makes rheumatoid arthritis less likely)
mild elevations in liver function test results
mild nonspecific synovitis
negative muscle biopsy findings
US may reveal multiple bursitis and tendonitis in the shoulder regions
Indications for referral
atypical features
age < 60yrs
chronic onset > 2 months
lack of shoulder involvement
lack of inflammatory stiffness
prominent systemic features of weight loss, night pain, or neurologic signs
features of other rheumatic disease
normal or extremely high acute phase response (ie. ESR or CRP)
treatment issues
incomplete or poor response to steroids
inability to taper steroids
C/I to steroids
prolonged steroid Rx > 2yrs
Mx
check for temporal arteritis
prednisolone
usual starting dose should be around 0.2mg/kg (ie. 12.5-15mg mane for most 60-70kg patients) 1)2)3)
may need higher dose if not responding within 7-14 days although some 25% do not respond to steroids
once responded, and ESR, CRP have fallen to much lower levels, then taper dose eventually hopefully a daily dose of 1mg/d may suffice, but may need Rx for 2-3 years
example regime for average body weight patients assuming adequate responses:
15mg/d for 3wks followed by weaning plan thereafter: 12.5mg for 3wks, then 10mg for 4wks, and then reduce by 1mg every month