Rheumatology: Rheumatoid Arthritis

Rheumatology: Rheumatoid Arthritis 2018-01-30T16:36:19+08:00

History

  • Symptoms
    • Early morning stiffness > 1 hour each morning
    • Duration of symptoms (≥ 6 months)
    • Pattern of joint involvement (symmetrical / asymmetric, small joint / large joint, oligo/polyarthritis)
    • Constitutional symptoms
      • Fever
      • Malaise
      • Lymphadenopathy
  • Functional status
    • How is this affecting your life?
    • Are you able to do things like unlock a door with a key or uncap a bottled drink?
    • Do you have any difficulty with buttons?
  • Extra-articular manifestations
    • Interstitial lung disease
      • Do you feel breathless when you walk?
      • Have you had a cough which has not gone away?
    • Rheumatoid nodules
      • Have you noticed any unusual bumps on your skin?
    • Raynaud’s phenomenon
      • Have you noticed your hands changing colour in the cold?
    • Episcleritis (painless) and scleritis
      • Have you ever noticed that your eyes are red?
      • Have you ever had pain in your eyes?
    • Glomerulonephritis
      • Have you ever noticed blood in your urine?
    • Systemic vasculitis
      • Have you noticed any rashes anywhere on your body?
      • Have you noticed any unusual bruises on your body?
      • Any skin ulcers?
    • Mononeuritis / polyneuropathy
      • Have you noticed any tingling in your hands or feet?
      • Have you noticed any weakness in your hands or feet?
  • Complications
    • Disease
      • Felty’s syndrome (neutropaenia, splenomegaly + RA, usually > 20 years)
        • Have you noticed any fullness in your tummy?
        • Do you feel you are getting the flu more often than usual?
      • Atlanto-axial subluxation
        • Is there any pain at the back of the head or neck?
        • Have you ever experienced the room spinning around you?
      • Anaemia
        • Do you feel tired?
        • Do you get any chest pain or short of breath when you walk?
      • Osteoporosis
        • Have you ever fractured a bone?
        • How did this happen?
      • Carpal tunnel syndrome
        • Do you notice any tingling in your thumb or index finger?
        • Do you have any problems using your thumb?
      • Secondary amyloidosis – nephrotic syndrome
    • Treatment
      • Steroids – exogenous Cushing’s, osteoporosis, cataracts, weight gain
      • Methotrexate – pulmonary fibrosis
      • Sulphasalazine – rash
      • Hydroxychloroquine – retinitis
      • Biologics – opportunistic infections
  • Rule out other disorders
    • Connective tissue disease
      • Systemic lupus erythematosus – mouth ulcers, alopecia
      • Mixed connective tissue disease – tightening of skin over digits
    • Arthritides
      • Psoriatic arthritis – itchy plaques on extensors
      • Polyarticular gout – asymmetric involvement, precipitants (meat, alcohol, diuretics)
      • Osteoarthritis – gets better with activity
  • Previous medication and compliance to current medication
    • Steroids: dose, compliance, recent change in dose
    • Disease-modifying anti-rheumatic drugs (DMARDs)
      • Sulphasalazine
      • Methotrexate
      • Leflunomide
      • Azathioprine
      • Gold
      • Hydroxychloroquine
      • Cyclosporin

Physical findings

  • Ask about joint pain before shaking the patient’s hand, especially if hand pain is the PC
  • Inspection:
    • Vasculitic lesions
    • Nail fold infarcts
    • Wasting of the small muscles of the hand
    • Wasting of thenar / hypothenar eminence
    • Swollen joints and their distribution
    • Symmetry
    • Deformities of rheumatoid hand:
      • Swan neck deformity: hyperextension of PIPJ with flexion at DIPJ and MCPJ
      • Boutonnier’s deformity: flexion at PIPJ with hyperextension of DIPJ and MCPJ
      • Z deformity of thumb: hyperextension of IPJ, fixed flexion and subluxation of MCPJ
      • Ulnar deviation of fingers
      • Subluxation of MCPJ
    • Rheumatoid nodules (usually over extensor surfaces of elbow and finger joints)
    • Scars suggesting previous decompression of carpal tunnel / tendon release
  • Look for active synovitis
    • Ask if any joints are painful again
    • Examine each small joint of the hand, then the other joints in turn
  • Function
    • Prayer sign / reverse prayer sign
    • Put your hands behind your head
    • Squeeze my fingers as tight as possible
    • Writing
  • Extra-articular manifestations
    • Look at eyes for scleritis / episcleritis
    • Listen for fine basal crepitations of interstitial lung disease
    • Listen for aortic regurgitation
  • Complications
    • Conjunctival pallor
    • Test forward flexion and extension of the cervical spine
    • Look for evidence of exogenous Cushing’s
    • Check for cataracts secondary to steroid use
    • Tinnel’s test for carpal tunnel syndrome

Differential diagnosis

  • Psoriatic arthritis
  • Polyarticular gout
  • Jaccoud’s arthropathy

Diagnostic criteria

  • Based on 2010 American College of Rheumatology criteria
  • Four criteria added together, score ≥6 is suggestive of rheumatoid arthritis
    • A – joint involvement (any swollen or tender joint on examination)
      • 1 large joint – 0
      • 2 – 10 large joints – 1
      • 1 – 3 small joints – 2
      • 4 – 10 small joints (± large joints) – 3
      • > 10 joints (at least 1 small joint) – 5
    • B – serology
      • RF and anti-CCP both negative – 0
      • RF or anti-CCP low positive – 2
      • RF or anti-CCP strongly positive – 3
    • C – acute phase reactants
      • CRP and ESR normal – 0
      • CRP or ESR elevated – 1
    • D – duration of symptoms
      • < 6 weeks – 0
      • ≥ 6 weeks – 1

Investigations

  • Serology:
    • Rheumatoid factor
      • IgM against Fc portion of IgG
      • Sensitivity 70 – 75%
      • Seropositive disease tends to be more erosive with extra-articular manifestations
    • Anti-cyclic citrullinated peptide
      • 90% specific
      • 60% sensitive
      • Positive CCP is a poor prognostic factor
    • Titers do not correlate with disease activity; purely diagnostic
  • Blood tests
    • Full blood count
      • Anaemia
        • Anaemia of chronic disease
        • Chronic GI loss secondary to NSAID use
        • Folate deficiency from methotrexate use
        • Renal anaemia
        • Felty’s syndrome
        • Autoimmune haemolytic anaemia
        • Pernicious anaemia (related condition)
      • Myelosuppression (methotrexate, gold, penicilliamine)
    • Liver function tests
      • Monitoring for adverse effects of DMARDs
      • Infiltrative, e.g. secondary amyloidosis
    • Renal function
      • Nephrotic syndrome from secondary amyloidosis
      • Primary disease process (membranous glomerulonephritis etc.)
  • Radiographs of hands looking for:
    • Juxta-articular osteoporosis
    • Marginal erosions
    • Soft tissue swelling
    • Joint space narrowing
    • Sub-chondral cysts

Management

  • Multidisciplinary, aim is to suppress inflammation before deformity and disability appear
  • Patient education – improves psychological symptoms and possibly pain scores
  • Physiotherapy and occupational therapy to preserve and maximize function
  • Bone protection (RA causes loss of bone density regardless of corticosteroid use)
  • Vaccination
  • Immunosuppression
    • Steroids – aim is to control symptoms with a low a dose as possible
    • DMARDs – delay disease progression and disability
      • Methotrexate – taken once-weekly
        • Adverse effects: pulmonary fibrosis, myelosuppression, transaminitis, ulcers
        • Baseline CXR, monthly FBC and LFT
      • Sulphasalazine
        • Adverse effects: rash, nausea, neutropaenia, deranged LFT
        • 3 monthly FBC and LFT
      • Leflunomide – expensive, taken either weekly or daily
        • Adverse effects: transaminitis, diarrhoea, alopecia, neutropaenia, hypertension
        • Monitor BP, 2 monthly FBC and LFT
      • Hydroxychloroquine
        • Adverse effects: nausea, corneal deposits, retinitis, rash
        • Monitor visual acuity annually
    • Biologics e.g. infliximab (anti-TNFα)
      • Expensive
      • Opportunistic infections, e.g. tuberculosis

Summary

Sir, this patient has a symmetrical, deforming polyarthritis which has been worsening over the past few months. The most likely diagnosis is rheumatoid arthritis. There is no evidence of extra-articular disease, such as rheumatoid nodules, interstitial lung disease or carpal tunnel syndrome. Functionally, the patient is able to write, use a key to open a locked door and undo the buttons on his shirt. Differentials include psoriatic arthropathy, although there are no psoriatic plaques, polyarticular gout, although there are no gouty tophi, and Jaccoud’s arthropathy, although there are no other manifestations of systemic lupus erythematosus.

This patient requires control of his inflammation, which can be done in the outpatient setting with corticosteroids in the first instance. He will require a baseline full blood count, liver function test and renal panel, as well as serologies before initiation of disease-modifying anti-rheumatic agents.

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