Rheumatoid arthritis Flashcards
How is Rheumatoid arthritis diagnosed?
Chronic (at least x6/52: insidious onset) inflammatory joint disease causing bilateral symmetrical polyarthritis in proximal joints of hands or feet
- Note: joint involvement may be less symmetrical in atypical presentation, early RA, early initiation of DMARDs
Presence of Rheumatoid nodules (fingers, behind elbow)/ peri-articular erosions on XR
Biological Markers:
1) RhF
- Not Required for Dx!
- Only +ve in 70% of RA Pt!
- Not Specific!
2) Anti-CCP
- Much more reliable
- Diagnostic & Prognostic marker
- As sensitive (70%) and more specific
What is the risk factors for RA?
F>M, commonly 40-60 years
Genetic assoc HLA DR4/DR1 (a/w poor prog)
***SMOKING IS IMPT RF –> promotes citrullination of proteins
What are the markers of poor prog for progression in early RA?
Clinical picture
- Insidious rather than explosive onset of RA
- Level of disability at onset of RA
- Female sex, old
- Increasing no. of peripheral joints involved
Blood tests
- High CRP/ESR
- Anaemia
- High titres of ACPA and RF
Imaging
- XR w early erosive damage
- (U/S and MRI show cartilage and bone damage earlier than XR)
What is the progression of RA joint manifestations?
Stage 1: Preclinical
- Not clinically apparent
- May have raised ESR, CRP RF
Stage 2: Synovitis
- Joint painful, swollen and tender
- Vascular congestion w angiogenesis, infiltration of immune cells into synovial membrane, proliferation of synoviocytes, cell rich effusion into joint and tendon sheaths
Stage 3: Destruction
- Erosion of bone (by osteoclastic resorption and granulation tissue invasion) and cartilage (by proteolytic enzymes, granulation tissue), disruption and rupture of tendons
Stage 4: Deformity
- Instability and deformity of joints
What is the clinical presentation of chronic progressive RA (70%)?
- Chronic (wks-mths) insidious onset, symmetrical, peripheral polyarthritis
- Relapsing, remitting course over several yrs
- Sero + pts higher risk of jt damage and LT disability -> Earlier DMARDs Tx!
What is the clinical presentation of rapidly progressive RA (15%)?
- Rapid onset (days or overnight), symmetrical, peripheral polyarthritis, progresses rapidly over a few years to severe joint damage and disability
- Esp in elderly
- Difficult to treat
- Usually sero +, w high incidence of systemic complications
What is the clinical presentation + course of rapidly Palindromic RA (5%)?
Features:
- Recurring short-lived episodes of acute mono/polyarthritis lasting 1-2 days
- Joints are acutely inflamed (pain, redness, swelling, disability)
- Symptom-free periods for days-mths, w NO PERMANENT DAMAGE
Course:
- 50% progress to other types of RA –> after delay of mths-yrs
- 50% remit or continue to have acute episodic arthritis
- Detection of RF/ACPA predicts progression to chronic, destructive synovitis
What is the clinical presentation + course of seronegative RA?
Seronegative are LESS AGGRESSIVE and LESS EROSION with Better long-term prognosis!
Opposite for Seropositive! Consider earlier aggressive DMARDs
Initially affects wrist more than fingers, and has less symmetrical joint involvement
What are the early articular symptoms & signs of RA?
Inflammation arthritis of proximal joints of hand (MCPJ and PIPJ [vs always DIPJ in OA]) and feet (MTPJ) spreading to other synovial joints eg shoulders and knees
Pain: worse in morning, ↓ by movement, a/w swelling, +/- redness, heat
Stiffness: early morning stiffness of >1hr, ↓ by movement, ↑ after resting
What are the late articular symptoms & signs of RA?
Rheumatoid deformities and limited ROM
Hand and wrists
• Ulnar deviation of MCP joints w MCP palmar subluxation
• Swan neck and boutonniere of fingers, Z thumb
• Radial and dorsal subluxation of ulnar styloid-> ‘piano key sign’; causes wrist pain +/- rupture of finger extensor tendons (req urgent Sx repair!)
Feet and legs
• Valgus knees, valgus feet and hammer toes
What are the C spine symptoms & signs of RA?
Atlanto-axial instability
AA instability –> subluxation –> SC compression (rare but NEUROSX EMERGENCY – do MRI C spine OR XR Lateral C Spine in Flexed & Extended positions)
Signs of subluxation
• Limited global ROM of C spine
• Neck pain radiating to bilateral occipital and parietal areas
• A/w paraspinal muscle spasm
• A/w audible ‘clunk’ on flexion – instability is accentuated on flexion!
Signs of Cervical Myelo: as above +
• Difficulty walking (unexplained by arthritis), LL weakness, and loss of bowel output + passing urine control, cannot feel toilet paper when wiping
• Clumsiness of hands, non-specific loss of sensation of UL
Note: Lateral flexed and extended C spine XR before Sx or endoscope to check for instability and↓ risk of cord injury during intubation
Note: AA instability not as common now due to intro of DMARDs
What are the MSK (non joint) features of RA?
- Tenosynovitis: dropped fingers (tendon rupture), trigger finger (trapped tendon in a thickened synovium)
- Carpal tunnel syndrome: due to tenosynovitis, wrist deformity
- Peri-articular muscle wasting
- Drug-induced myopathy (eg glucocorticoids)
What are the CVS features of RA?
- ↑ risk of CAD, possibly heart failure and atrial fibrillation (poorly controlled RA w persistently high CRP and high cholesterol is CVRF)
- Pericarditis, endocarditis (usually subclinical) -> 10% Carditis detected clinically, 30% on echo
- MR, AR
What are the respi features of RA?
- Cricoarytenitis (RA of Cricoarytenoid joint) -> hoarse voice
- ILD eg cryptogenic organising pneumonia
- Pleural effusion (from serositis)
- Bronchiectasis
- Reactivation of TB 2° to DMARD use
- Rheumatoid nodules in lungs
What are the neuro features of RA?
Peripheral sensory neuropathies 2’ vasculitis of vaso vasorum eg mononeuritis multiplex, symmetrical peripheral polyneuropathy
Mononeuritis Multiplex is a class of peripheral neuropathy
- Occurs when there is damage to nerves in separate areas of the body!
- Neuropathy of 1 nerve = mononeuropathy
- Neuropathy of >1 nerve in 1 location = polyneuropathy
- Neuropathy of nerves in multiple non-contiguous locations = mononeuritis multiplex (or also called polyneuritis multiplex)
- Results in loss of sensation / loss of motor function / pain
- Asymmetric involvement
- But as the disease progresses, deficit(s) becomes more confluent and symmetrical, making it difficult to differentiate from polyneuropathy.
- Therefore, attention to the pattern of early symptoms is important
Entrapment neuropathy –> CTS or TTS (tarsal tunnel syndrome)
C myelopathy 2’ cord compression from atlanto-axial sublux