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
What are the haem features of RA?
Anaemia
- NCNC usually (ACD, haemolysis from hypersplenism in Felty’s),
- microcytic (IDA due to BGIT from NSAID/steroids)
- megaloblastic (pernicious anaemia, MTX-induced folate def, AIHA)
Thrombocytosis in active disease
Sometimes mild leucocytosis
Felty syndrome: RA + neutropenia + splenomeg
What are the eye features of RA?
Sclera: episcleritis/scleritis
Conjunctiva: keratoconjunctivitis sicca (Sjogren’s)
- keratoconjunctivitis sicca = dryness of conjunctiva and cornea
- Secondary Sjogren’s can occur in pt w pre-existing Rh Dz (RA, SLE etc)
Lens/vitreous: cataracts/ glaucoma from prolonged steroids
Fundus: vasculitis, chloroquine-induced maculopathy
What are the cutaneous features of RA?
**Rheumatoid nodules (pathognomonic) –> firm, intradermal, over pressure points (elbows, finger joints, Achilles tendon)
Vasculitis (small vessel) –> palpable purpura, nailfold and digital infarcts (splinter haemorrhage)
Vasculitis (large vessel) –> ulcers, digital gangrene (vasculitis is not significant compared to other CTDz)
Palmar erythema
What are the investigations to be performed for RA?
Basic bloods
- FBC: often NCNC anaemia 2’ ACD
- ESR, CRP: a/w disease activity
- RP LFT: for Mx
Autoantibodies
- RF: +ve in 40% of pts w early RA, but in 60-80% during course of disease
- Anti-CCP: higher specificity (90-98%) than RF
- ANA: +ve in 40% of pts
RF and CCP is somewhat prognostic and determines aggressiveness of Dz
Imaging
- XR
o Early (synovitis): juxta-articular osteopenia, soft tissue swelling
o Late (destruction): uniform narrowing of joint space, juxta-articular bony erosions, NO osteophytes
o Advanced (deformity): articular destruction and joint deformity
- MRI: synovitis, early erosions, useful in cervical spine disease
Evaluate disease activity - DAS28 can be used to evaluate disease activity, and help monitor effectiveness of therapy
- Range from 2.0-10.0 (higher number = higher Dz activity)
- 28 = 28 different joints included in the measurement
- DAS = Disease Activity Score
How do you manage a patient with RA?
1) Symptom control: reduce pain/swelling/inflammation
- SMOKING CESSATION
- NSAIDs for pain: TRO PUD, Allergy, Renal Impairment
- Short course low dose Prednisolone for flares
2) Disease modification: reduce synovitis and joint damage, increase function
- DMARDs ASAP (DMARDs take 2-3months to be effective)
- KIV escalation to biologic agents (1st line TNFα-inhibitors, 2nd line Rituximab, 3rd line tocilizumab & abatacept) – is expensive but may be more effective, consider if severe
3) Optimizing function:
- PT: rest during flares, exercise to maintain ROM and muscle power
- OT: manage ADLs
- Surgery: prophylactic (joint stabilisation), reconstructive (e.g. tendon repair, arthroplasty), urgent synovectomy (in uncontrolled RA synovitis causing massive soft tissue swelling)
Aim to reduce DAS28 to <2.6
- if <2.6, considered REMISSION 😊
What if a patient requires DMARDs but want to get pregnant?
If planning to conceive, give pred + SSZ (but slow onset), monitor FBC and LFT
- MTA and LEF are teratogenic!
- SSZ & HCQ are not, but SSZ is more effective 😊
- All DMARDs are Myelosuppressive & hepatotoxic -> hence monitor FBC & LFTs
What do you need to monitor for when starting DMARDs?
1) Screen for Latent Infections (HSV, EMV, CMV, Tb, HBV, VCZ)
2) Monitor FBC and LFTs (all are myelotoxic and hepatotoxic)
3) Assess G6PD Def (for SSZ and HCQ)
4) Ophthalmology Assessment (for HCQ)
What are the C/Is of Methotrexate?
C/I in pregnancy – delay conception 3-6/12 off the drug for either partner
C/I in renal impairment, liver cirrhosis, HBV/HCV carrier
What are the S/Es of Methotrexate?
- TB reactivation: CXR, IGRA in high risk pts to exclude TB
- Pneumococcal and yearly influenza vacc
- N&V & poor absorption might reduce efficacy: change to SC
- Myelosuppression due to anti-Folate activity: monitor FBC, give adjunct folic acid 5mg once a week: Folic acid does not antagonist MTX effects
- Hepatotoxicity causing transaminitis: monitor LFTs
- GI S/E: mouth ulcers, dyspepsia
What are the S/Es of Hydroxychloroquine?
Bull’s Eye maculopathy: Irreversible retinopathy 2’ retinal toxicity (1/2000): baseline macular fx using Amsler chart w annual reviews + Humphrey visual field testing
Caution in G6PD def, may cause haemolysis
What are the side effects of Leflunomide?
Avoid in pregnancy (due to long half-life of 4-28 days)
Diarrhoea (diminishes w time)
What are the side effects of TNFa blockers e.g. Infliximab, Adalimumab?
TB reactivation: CXR, IGRA in high risk pts to exclude TB. Treat if active, prophy if latent before starting TNF-a
Infections: hep screen
Heart failure: C/I in severe heart failure
What is the American College of Rheumatology (ACR) criteria for disease remission (≥5 criteria below for at least 2/12)?
- Morning stiffness <15min
- No fatigue
- No joint pain, joint tenderness
- No soft tissue swelling or tendon sheaths
- ESR <30 in women, <20 in men
What hx do you need to take in a patient with RA?
Ask about the joint pain, characterise it
Assess risk factors
Functional assessment
Extra articular manifestations
Assess RF for treatment
- Methotrexate: Macrocytic Anaemia
- NSAIDs: BGIT and NCNC Anaemia
- DMARDs: Myelosuppression (anaemia, easy bruising, infection)
Assess complications of treatment
What does the RHEUMATOIDS mnemonic for extra-auricular features of RA stand for?
- Respiratory
- Hematological
- Eyes – Episcleritis / Scleritis; Ant Uveitis, Sicca
- Ulcers and other skin manifestations
- Mononeuritis multiplex
- Atlanto-axial subluxation
- Tendon rupture / Tenosynovitis (trigger finger, CTS, TTS)
- Osteoporosis
- Incompetent valves (mitral/aortic regurgitation)
- Dry eye and mouth – Sjogren’s
- Serositis eg pleural effusion and pericarditis (pericarditis can lead to pericardial effusion)
