Rheumatology - Polyarthritis - OA, RA, SpA Flashcards
List causes of polyarthritis
Non-inflammatory:
- OA
- Fibromyalgia
Inflammatory:
- RA
- Viral polyarthritis
- Infective: IE, rheumatic fever, bacterial polyarthritis, Lyme disease
- Connective tissue disease/ SLE
- Spondyloarthritis (SpA): Ankylosing spondylitis, Psoriatic arthritis, Reactive arthritis, IBD-related arthritis
- Crystal deposition disease: Gout, Pseudogout, Lipid, Calcium…etc
Most likely cause of polyarticular pain in this profile:
Young age
Insidious onset
symmetrical arthritis involving small and large joints in upper and lower limbs
Spares DIP
Morning stiffness that resolves after some time
Rheumatoid arthritis
Most likely cause of polyarticular pain in this profile:
Old age
symmetrical polyarthralgia affecting DIP, PIP, 1st CMCJ, weight-bearing joints and neck
Insidious onset
Typically (at least initially) associated with movement and resolved with rest
Osteoarthritis
Most likely cause of polyarticular pain in this profile:
Acute onset of monoarticular pain with recurrent attacks
Affects distal > proximal joints in a migratory/simultaneous pattern
Systemic upset, fever during acute attacks
Overlying skin is pruritic
Gout
Most likely cause of polyarticular pain in this profile:
Young age, insidious onset
Wide distribution of peripheral and axial joints affected, asymmetrical
Associated with back pain, psoriasis, uveitis and other widespread S/S
Spondyloarthritis
Differentiate mono, oligo and polyarthritis/ -arthalgia
1= mono
2-4 = oligo
≥5 joints = poly
Rheumatoid arthritis
Joints affected by RA
Classical deformities in chronic cases
Classically symmetrical arthritis involving small and large joints in upper and lower limbs
Classically starts in MCP, PIP, wrists and MTP joints and spares DIP joint
Eventually spread to involve multiple peripheral joints ± atlantoaxial joint (C1/2), cricoarytenoid
Deformities: swan neck/Boutonierre deformity, Z thumb, rheumatoid nodules
Spondyloarthritis
Joints affected
Extra-articular features
Axial form: SI joint and other interarticular joints
Peripheral form: asymmetrical oligoarthritis (LL>UL), DIP not spared
Extra-articular:
- enthesitis, dactylitis (sausage digits due to tendinitis)
- anterior uveitis, conjunctivitis/urethritis (in reactive arthritis)
- psoriasis (in PsA)
- IBD (in IBD-associated SpA)
Viral polyarthritis
Causative pathogens
Joints affected
- Common associations: hep B and C, EBV, parvovirus B19, Dengue virus, rubella, HIV
- Symmetrical, small joint arthritis ± rash and prodromal illness → usually self-limiting ≤6w
Outline history taking approach for polyarthritis
- Inflammatory vs non-inflammatory pain?
- Pain localized to joint or extra-articular?
- Onset/ triggers? e.g. conjunctivitis in SpA
- Acute or chronic:
Acute: Crystals, reactive, septic, viral
Chronic, SpA, RA, OA, Connective tissue diseases… - Joints: mono-, oligo- or polyarthritis
- Spatial pattern: symmetrical vs asymmetrical, large or small joints, axial or peripheral
- Temporal pattern: Migratory or additive or intermittent
Features of inflammatory joint pain
→ Early morning stiffness: lasts >30min after waking (classical in RA)
→ Swelling, heat, redness in joints
→ Better with gentle exercise and worse with rest
Ddx symmetrical vs asymmetrical polyarthritis
Symmetrical:
RA, SLE, OA
Asymmetrical:
Psoriatic SpA
Axial SpA
Peripheral SpA
Ddx polyarthritis with migratory, additive and intermittent patterns
Migratory pattern: symptoms present in certain joints for a few days then remit, only to reappear in other joints
- rheumatic fever, gonococcal arthritis and SLE-associated arthritis
→ Additive pattern: symptoms begin in some joints and persist with subsequent involvement of other joints
- RA and SLE
→ Intermittent pattern: repetitive attacks of acute polyarthritis with complete remission between attacks
- RA, polyarticular gout and palindromic rheumatism
Rheumatoid arthritis
Extra-articular features and asso. S/S
Constitutional or systemic symptoms: weight loss, fatigue, anaemia of chronic disease ± Felty syndrome
Musculoskeletal: osteopenia/osteoporosis, muscle weakness, steroid-related myopathy, carpal tunnel syndrome
Skin: digital ulcers,Rheumatoid nodules (20-35%): common on pressure points
Eye: Episcleritis, Scleritis
RA-related ILD, lung nodules and pericarditis
Rheumatoid vasculitis
Hepatosplenomegaly
SLE
Extra-articular features
Constitutional or systemic symptoms: fever, weight loss, myalgia, fatigue, anaemia of chronic disease
Cutaneous lupus: buttery fly rash (acute), annular/papulosquamous (subacute), discoid rash, scarring alopecia
Raynaud’s phenomenon, Lupus vasculitis
GI: oral/mucosal ulcers, protein-losing enteropathy, Hepatitis
Lupus nephritis
Serositis (pericarditis, pleuritis),
ILD and pulmonary hypertension
Cerebral lupus, and thromboembolic stroke
Eye: keratoconjunctivitis sicca, episcleritis/scleritis/uveitis
Haematological: haemolytic/NcNc anaemia, APS, Lymphadenopathy and hepatosplenomegaly
SpA
Extra-articular features
Dactylitis (sausage digits)
Enthesitis: common at insertion of Achilles tendon
Psoriatic changes: skin psoriasis, nail pitting, dystrophy
Uveitis (a/w most types of SpA), IBD (in IBD-associated SpA), urethritis/conjunctivitis (in reactive arthritis)
Vasculitis-caused polyarthritis
Extra-articular features
Constitutional or systemic symptoms: fever, fatigue, weight loss, arthralgia
Livedo reticularis: non-blanching palpable purpuric rash at dependent areas or pressure sites
Nail fold erythema, splinter haemorrhages
palmar/finger pulp vasculitis- digital ulcers/gangrene
Renal and pulmonary involvement
First-line investigations for polyarthritis
□ CBC/L/RFT
□ ESR/CRP
□ Serum urate
□ ANA, anti-ENA, C3/4 if suspicious for SLE
□ Rheumatoid Factor, anti-CCP if suspicious for RA
□ HLA-B27 if suspicious for SpA
□ Plain XR of affected joint: as mainstay
□ Other imaging:
→ USG: guide aspiration and injections, detect synovitis
→ MRI: for neurological complications, other Cx
→ Bone scan for inflammatory activity
→ CT scan for structural complications, eg. pseudoarthrosis, ILD
Radiological features of OA, RA joints
→ OA: subchondral cyst, osteophytes, ↓joint space, subchondral sclerosis
→ RA: marginal erosion, ↓joint space, soft tissue swelling, osteoporosis
Radiological features of SLE, SpA joints
→ SLE: typically non-erosive (osteoporosis, soft tissue swelling with normal joint spaces)
→ SpA: SI joint sclerosis, spinal marginal syndesmophytes or parasyndesmophytes
Joints affected by chronic tophaceous gout
Site: extensor surface of fingers, hands, forearm, elbows, Achilles tendons, helix of ear
OA
Typical joints affected
Single or multiple joint OA
o Predilection for hands (PIP/ DIP/ 1st CMC/ 1st MCP), knee, hip and apophyseal (facet) joints of lower cervical and lower lumbar spine
Generalized OA
o Defined as OA at spinal or hand joints and in at least 2 other joint areas/ 3 joints, presence of Heberden’s nodes and Bouchard’s node
Differentiate primary vs secondary OA
Primary OA
o Idiopathic and related to genetics
Secondary OA
o Secondary to abnormal mechanical forces or previous joint insult
o Predisposing conditions including trauma (fracture), rheumatoid arthritis, avascular necrosis, Paget’s disease of bone
OA
Demographics
Risk factors
Demographics: >40 years old, female predominant
RF: Age Obesity Trauma Occupational usage (Farmer’s hip)/ Heavy weight-lifting Recreational usage (Footballer’s knee)
OA
Pathogenesis of articular damage
Articular cartilage
• Loosening of collagen network and loss of extracellular matrix in cartilage
- Proliferation of chondrocytes and swelling of cartilage
- Production of matrix metalloproteinases (MMP) and pro-inflammatory cytokines
- Chondrocytes death leading to cartilage loss and joint space narrowing
OA
Pathogenesis of bone changes
• Osteophyte formation
o Bone spurs or outgrowths form at joint margins often at insertion site of tendons and ligaments attempt to stabilized the joints
• Subchondral sclerosis
o Thickening of subchondral bone due to increased production of collagen that is improperly mineralized attempt to support framework beneath cartilage
• Subchondral cysts
o Cartilage damage transmit pressure of synovial fluid to bone
o Extravasation of fluid into subchondral bone to form subchondral cysts
OA
Pathogenesis of synovium and soft tissue damage
Synovium
• synovial inflammation (synovitis) or synovial hypertrophy
Soft tissues
• joint capsule, ligaments and menisci (in knees) are commonly affected with disruption of extracellular matrix and loss of cells
» Thickening of joint capsule, ligaments and menisci tearing
• Periarticular muscles and nerves are also affected
SOCRATES for OA joint pain
- Site: Affects one or few joints at a time
- Onset: Insidious onset with slow progression over years
- Character: Sharp or dull aching pain
- Associated symptoms: Stiffness, swelling, decrease ROM
- Time course: Intermittent
- Exacerbating factor: Joint use
- Relieving factor: Resting
- Severity: Variable in intensity