Rheumatoid Arthritis

• Chronic, symmetric, erosive synovitis of peripheral joints (wrists, MCP, MTP)
• Characterised by a number of extra-articular features

Epidemiology

• F:M = 3:1
• Age of onset between 20-40
• Genetic predisposition (HLA DR4/DR1 association)

Diagnostic criteria (4 or more of):

• Morning stiffness (>1 hour) for > 6 weeks
• Arthritis of 3 or more joint areas (commonly involved joints include PIP, MCP, wrist, elbow, knee, ankle, MTP) for > 6 weeks
• Arthritis in at least 1 of: MCP, PIP, wrist for > 6 weeks
• Symmetrical arthritis for > 6 weeks
• Rheumatoid nodules
• Serum RF (found in 60-70%)
• X-ray changes – erosions or periarticular osteopenia (most likely to see earliest changes at the ulnar styloid or at the 1^st & 2^nd MCP joints and at the 1^st & 2^nd PIP joints)

Clinical Manifestations

Stage	Manifestations	Signs	Radiographic changes
1	Usually none	–	–
2	Malaise, mild joint stiffness & swelling	Swelling of small joints of hands or wrists or pain in hands, wrists, knees & feet	–
3	Joint pain and swelling Morning stiffness, malaise & weakness	Warm, swollen joints, effusion, soft tissue proliferation within joints, pain & limitation of motion, rheumatic nodules	Soft tissue swelling
4	As above	As above but more pronounced swelling	MRI – proliferative pannus X-ray – periarticular osteopenia
5	Stage 3 and loss of function & early deformity (e.g. ulnar deviation at the MCP joint)	As above + joint instability, flexion contractures, ↓ ROM, extra-articular complications	Early erosions, joint space narrowing

Bad prognostic factor in RA

1. Hyper-acute onset (overnight onset)
2. Multiple joint involvement (especially >20 joints)
3. High titer Rheumatoid Factor (RF)
4. HLA-DRBI 0404
5. Low dose Corticosteroid resistance
6. Early loss of function or young age of onset
7. Higher Erythrocyte Sedimentation Rate
8. Rheumatoid Arthritis Extra-articular Signs

Complications:

• Joint deformities
  • Swan neck: Hyperextension of PIP, flexion of DIP
  • Boutonniere: Fixed flexion contracture of PIP, extended DIP
  • Ulnar deviation of MCP, radial deviation of wrist joint
  • Hammer toes – subluxation of heads of MTP, foreshortening of extensor tendons
  • Flexion contractures
• Limited shoulder mobility, dislocation, spontaneous tears of rotator cuff leading to chronic spasm 
• Tendon sheath involvement – tenosynovitis → may cause rupture of tendons
• Compression of carpal tunnel – thenar atrophy, tingling of thumb, index & middle finger
• Ruptured Baker’s cyst (outpouching of synovium behind the knee) – similar presentation to thrombophlebitis
• Anaemia of chronic disease
• High ESR, hypogammaglobulinemia
• Early mortality

Extra-Articular Features

• Constitutional: wt loss, malaise, lethargy, fatigue, anaemia, LNs
• Reactive depression + sleep disorders
• Are due to either a vasculitis or a lymphocytic infiltrate

• Vasculitis
  • Episcleritis/scleritis
  • Rheumatoid nodules (25-50%): subcutaneously in bursae, along tendon sheath, over pressure point (olecranons + ulnar border of forearm), Achilles tendon, ischial spine
  • Periungual infarction
  • Skin ulcers
  • Neuropathy
• Lymphocytic infiltration
  • Sjogren’s syndrome
  • Pulmonary fibrosis
  • Pleural effusion/Pleurisy/lung nodules
  • Pericarditis/myocarditis/valvular disease
  • Hashimoto’s fibrosis
  • Hepatosplenomegaly (F(P)elty’s syndrome – neutropenia, RA, splenomegaly)

Functional classification:

• Class I: No restrictions
• Class II: Moderate restriction, able to perform normal activities
• Class III: Marked restriction, can’t perform activities of usual occupation/self-care
• Class IV: Incapacitation, confinement to wheelchair

Management:

• Control inflammation
• Relieve pain & stiffness
• Maintain function and lifestyle
• Prevent joint damage

Options:

• Education, counselling, OT, dietary therapy (e.g. selenium)
• Medical therapy – key is early diagnosis and early intervention with DMARDs

DMARDs:

• Decrease erosions and associated with better long-term disability
• Commonly used:
  • Antimalarials (e.g. hydroxychloroquine)
  • Gold
  • Methotrexate
    • Oral and Gastrointestinal (most common) – Nausea, Oral Ulcers, Stomatitis, Diarrhea
    • Hepatic: Hepatic fibrosis, Elevated transaminases, Cirrhosis
    • Pulmonary: Pulmonary fibrosis or infiltrates, Hypersensitivity Pneumonitis
    • Neuropsychiatric: Dysphoria
    • Hematologic: Minimal Immunosuppression (Contrast with Imuran). Myelosuppression, Thrombocytopenia
  • sulfasalazine
  • Less used: Azathioprine (Imuran)

NSAIDs:

• Symptom control – decrease joint pain, tenderness, morning stiffness but don’t alter natural history
• Side effects
  • GI: dyspepsia, PUD 🡺 Rx: omeprazole gastroprophylaxis
  • Renal: Reversible ↓GFR + (rarer) ARF/CRF. interstitial nephritis, papillary necrosis, hyperK

Corticosteroids

• Useful short-term adjuvants
• Local use – intra-articular injections, eye drops or systemic use (vasculitis, severe refractory disease)

Corticosteroid Side effects

• Eyes:
  • glaucoma, cataract
• HPA axis suppression:
  • Hypogonadism
  • menstrual irregularity
  • Corticosteroid Induced Adrenal Insufficiency
    • Typically does not occur if Prednisone 20 mg equivalent used <2-3 weeks
    • NB severe stress (🡺Rx: single short-acting dose NB stress dose of glucocorticoids + not stop steroid abruptly – need tapering)
• GI:
  • Pancreatitis
  • Candidiasis
  • PUD
• Immunosuppression:
  • ↑infx risk (TB, chickenpox),↓wound healing 🡺 Rx: immunization
• Endocrine:
  • Cushingnoid (central obesity, striae, moon face, thin skin, easy bruising)
  • Hirsuitism
  • Hyperglycaemia
  • fluid + electrolyte abnormalities (hypoK, Na retention)
  • hyperlipidaemia 

🡺 Rx: monitor BSL, BP, lipid +↓dose

• M/skeletal:
  • Osteoporosis
  • Myopathy
  • ischaemic bone necrosis (aseptic necrosis, avascular necrosis esp @ humeral head, femoral hear, tibial plateau) 🡺 Rx: Caltrate 1-1.5g/day po, vit D, estrogen, bisphosphanate, calcitonin +/- HRT for postmenopausal♀
  • –>  wt baring exercise
• Psychiatric:
  • Psychosis
  • Euphoria
  • Depression
  • emotional liability