Achy shoulders and a
very high CRP
Sarah Tansley
Rheumatology, Clinical Fellow
Case discussion
A
case of polymyalgic onset rheumatoid
arthritis was discussed – details removed
for confidentiality purposes.
PMR diagnosis
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Core Inclusion criteria
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Age > 50
Bilateral shoulder or pelvic girdle aching or both
Morning stiffness >45 minutes
Evidence of acute phase response
No active cancer, active infection or active GCA
No urgency to start steroids – can investigate
first
Factors which Increase the likelihood of a
non-PMR diagnosis
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Age <60 years
Chronic Onset
Lack of shoulder involvement
Lack of inflammatory stiffness
Normal or very high CRP
Peripheral arthritis
Systemic symptoms, weight loss, neurological signs
Incomplete or non-response to steroids
15mg Prednisolone should result in >70% improvement
within 1 week and normalisation of inflammatory markers
within 4 weeks
Who to refer
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BSR guidelines recommend specialist referral when
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Age <60
Chronic onset >2 months
Lack of shoulder involvement
Lack of inflammatory stiffness
Prominent systemic features; weight loss, night pain,
neurological signs
Features of other rheumatic disease
Normal or extremely high acute phase response
Treatment dilemmas (inadequate response to steroids, inability
to reduce steroids, contraindication to steroids etc)
RA diagnosis
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Aim for early diagnosis and treatment but lack of
features of established disease can cause difficulty
Considerable variability in presenting symptoms and lab
results
History
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Polyarticular involvement –may be small number of joints initially
Morning stiffness (>30 minutes) suggests inflammatory joint pain
Chronicity
Examination
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Joint tenderness MCP, MTP, wrists
RA nodules, not usually seen until later
Upper and lower extremity involvement
Synovitis
Rheumatoid Arthritis Investigations
 No
single diagnostic test
 Serology
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RF
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•
•
•
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Positive in 70-80% of patients with RA
May be negative, especially early
Also seen in other conditions eg Sjogrens Syndrome
Positive in 5-10% of healthy individuals
Anti- CCP Abs
• As sensitive
• Much more specific
Rheumatoid Arthritis Investigations
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Inflammatory markers
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Full blood count
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Non-specific
Useful for distinguishing inflammatory conditions from
non-inflammatory
Anaemia of chronic disease, leucocytosis,
thrombocytosis
Radiology
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Erosions of cartilage and bone
Presence more useful diagnostically with increasing
duration of disease
Radiology
ACR/EULAR classification criteria
Score
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Designed to classify patients
as RA earlier for purpose of
clinical trials – not diagnostic
criteria
Still useful, several differences
from 1987 criteria which aimed
to classify people with
established disease
Target population
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At least 1 joint with definite
synovitis/swelling
Synovitis not better explained
by another disease
Score >6 classified as RA
Joint Involvement
1 large
0
2-10 large
1
1-3 small
2
4-10 small
3
>10 joints
4
Serology
Negative RF & anti-CCP Ab
0
Low positive RF or anti-CCP Ab
2
High positive RF or anti-CCP Ab
3
Acute Phase Reactants
Normal CRP & ESR
0
Abnormal CRP or ESR
1
Duration of Symptoms
< 6 weeks
0
>6 weeks
1
Polymyalgic onset RA
 Bajocchi et al 2000
 LO-RA vs YO-RA
• Polymyalgic symptoms more common in LO RA
• Higher frequency of shoulder involvement in LO
RA
 Lopez-Hoyos et al 2004
 Anti-CCP Abs in differential diagnosis of RA
vs PMR
• 65% LO RA anti-CCP Ab +ve
• No PMR patients anti-CCP Ab +ve
• Polymyalgic onset RA 2/10 anti-CCP +ve
Polymyalgic onset RA
 Gran,

Mykebust 1999
Incidence and Characteristics of peripheral
arthritis in PMR & TA
• 231 patients prospectively studied 1987-1993
• All ?PMR/TA in Norwegian county referred to
rheumatology before treatment
• Followed throughout the disease course
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187 ‘pure’ PMR
38.5% developed peripheral arthritis
11 developed RA (4.8% 6 female and 5 male)
Polymyalgic RA
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Mean duration of PMR at RA diagnosis
was 63.2 months
5/8 patients had erosive x-ray changes
6/11 patients had positive RF (all
negative initially)
Mean CRP higher at diagnosis among
those who developed arthritis (88.6 vs
59.7)
Polymyalgic onset RA
 Pease
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et al 2009
Prospective study of 147 patients presenting
with PMR & 142 patients with LO-RA
Reviewed accuracy of initial diagnosis
• 23% PMR patients had peripheral synovitis
• In contrast to seronegative LO-RA, PMR
patients younger, myalgia more frequent,
PIP/MCP/wrist arthritis less frequent
• Combination of wrist + MCP and/or PIP
highly suggestive of RA
Polymyalgic onset RA
 Pease
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et al 2005
349 patients with new onset LO-RA, PMR or
TA >60 yrs
• 9/171 initially diagnosed PMR changed to LO-RA
• All 9 dependant on higher steroid dose than
typically expected for their stage of disease
• Initially synovitis suppressed by steroids but
returned when dose lowered
• Initial plasma viscosity higher in this group (mean
of 2.0 vs 1.86)
• Difficulty to distinguish may lead to delay in correct
diagnosis (average 13 months)
Summary
 Several
challenges in diagnosing RA,
particularly early in the disease course
 Variety of possible presentations
 Polymyalgic symptoms are common in
elderly onset RA
 May lead to diagnostic delay
 No single diagnostic test; clinical history
and examination important