MCQ – 72003

A patient suffering from morning stiffness,presents with the follwing abnormality in the X ray.What can be the most possible diagnosis?

  

A.	Psoriatic Arthritis
B.	Rheumatoid Arthritis
C.	Osteoarthritis
D.	Relapsing polychondritis

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Correct Answer � B Explanation

Ans:B.)Rheumatoid Arthritis.

Image shows: Severe rheumatoid arthritis of the wrist and hand. The ulnar styloid is destroyed with the rest of the distal ulna (white arrow), there is destruction of the carpal bones (yellow arrow) and there is dislocation of the 1st metacarpal on the destroyed trapezium (blue arrow). All of the bones are osteopenic.

RHEUMATOID ARTHRITIS

• Most common inflammatory arthritis in women
• Symmetric peripheral polyarthritis
• Female gender, cigarette smoking are risk factors
• Strongly associated with HLA-DR4

Pathogenesis:

• Accumulation of neutrophils in the synovial fluid and along the synovial surface(not in the synovial stroma)
• Aggregation of organizing fibrin covering the portions of synovium and floating in the joint space as rice bodies
• Pannus formation – a mass of synovium and synovial stroma consisting of inflammatory cells, granulation tissue and fibroblasts which causes erosion and destruction of articular cartilage (principle target) eventually resulting in ankylosis

Clinical features:

• Early morning joint stiffness lasting more than 1 hour and easing with physical activity
• Earliest involved joints are typically the small joints of the hands and feet
• Wrists, metacarpophalangeal (MCP), proximal interphalangeal (PIP) joints are most frequently involved
• Subcutaneous rheumatoid nodules, most commonly situated over bony prominences but also observed in the bursae and tendon sheaths

Joints involved:

• Symmetrical involvement of MCP, PIP and MTP
• Large joint involvement is common but occurs later
• Spine is spared except the cervical spine which is commonly involved

Deformities:

• Flexor tendon tenosynovitis is a frequent hallmark of RA and leads to decreased range of motion, reduced grip strength, and trigger fingers
• Swan neck deformity– hyperextension of PIP with flexion of DIP
• Button hole or boutonniere deformity – flexion of the PIP joint with hyperextension of the DIP
•  Z-line deformity of the thumb – subluxation of the first MCP with hyperextension of the first interphalangeal (IP) joint
• Ulnar deviation of fingers – subluxation of MCP, with subluxation of the proximal phalanx to the volar side of the hand
• Cock-up toe – dorsal subluxation of MTP
• Piano-key movement of the ulnar styloid – inflammation about the ulnar styloid and tenosynovitis of the extensor carpi ulnaris
• Pes planovalgus (flat feet)
• Hammer toe & Wind – sweep deformities of toes
• Late triple knee deformity

Laboratory features:

• Synovial fluid WBC counts: 5000 – 50,000 WBC/μ3(

Radiological features

• Juxtaarticular osteopenia
• Bone erosions (often first evident at the ulnar styloid and at the juxtaarticular margin)
• Narrowing of joint space due to loss of articular cartilage

Rheumatoid factor

• Autoantibody, usually IgM
• Not specific for RA (absence cannot exclude RA); Positive in 70-90% patients
• Positive RF is associated with worse prognosis
• Level parallels the activity of the disease
• Anti-CCP antibody more specific than Rheumatoid factor in the diagnosis of RA
• Anti-CCP positivity – worse prognosis

Criteria for diagnosis of RA (four or more of the following)

• Morning stiffness > 1hr
• Arthritis of 3 or more joints
• Arthritis of hand joints
• Rheumatoid nodules
• Rheumatoid factor
• Radiological changes
• Duration of 6 weeks or more

Extra articular manifestations – more common under the following conditions

•  History of smoking
• Early onset of significant physical disability
• Test positive for serum RF
• Ocular
  • Scleritis, episcleritis
  • Scleromalacia
  • Keratoconjunctivitis sicca
• Felty’s syndrome
  •  Nodular RA
  • Splenomegaly
  • Neutropenia
• Amyloidosis
• Cardiac
  • Pericarditis(MC),myocarditis,endocarditis
  • Pericardial effusion
  • Conduction defects
• Vasculitis
  • Pyoderma gangrenosum
  • Mononeuritis multiplex
• Pulmonary
  • Nodules (MC)
  • Fibrosing alveolitis
  • Bronchilitis
  • Exudative Pleural effusion with low glucose and pH
• Caplan’s syndrome
  • Coal worker’s pneumoconiosis
  • RA

Treatment:

• DMARDs- methotrexate (first choice) hydroxychloroquine, sulfasalazine, leflunomide
• NSAIDs, Corticosteroids
• Anti-TNF-α: Etarnacept, Infliximab, Certolizumab
• Anakinra (anti-IL-1), abatacept, monoclonal antibody(rituximab, tocilizumab)