Rheumatology: Ankylosing Spondylitis

Rheumatology: Ankylosing Spondylitis 2018-01-30T16:36:19+00:00

Clinical features

  • Males more commonly affected (2.5 : 1)
  • Inflammatory back pain
    • Typically starts in third or fourth decade of life
    • Insidious onset
    • Worse in the morning or after periods of immobility
    • Better with exercise
    • May have difficulty sleeping
    • Not relieved by resting
    • May have buttock pain (sacroiliac involvement)
    • Can have symptoms anywhere along the spine
    • Relieved by NSAIDs
    • Family history of spondyloarthropathy
  • Other manifestations
    • Peripheral arthritis
    • Enthesitis
    • Dactylitis
    • Anterior uveitis (acute, unilateral painful red eye with photophobia, blurring of vision)
    • Aortic regurgitation (sclerosing inflammation resulting in decreased elasticity of the aortic root)
    • Extra-Athoracic restrictive lung disease (diminished chest wall and spinal mobility)
    • Apical pulmonary fibrosis
  • Spinal involvement
    • Modified Schober test (anterior lumbar spinal flexion)
      • Midpoint of the line joining the two posterior superior iliac spines
      • Note the position 10cm above and 5cm below this point with the patient standing
      • Ask the patient to bend forward as much as possible, while keeping legs straight
      • Distance between the two points should increase by ≥ 5cm
    • Lateral cervical and lumbar spinal flexion
    • Occiput to wall distance (normal people should be able to touch occiput to wall when standing)
    • Cervical spine and thoracic spine rotation
  • Complications
    • Spinal cord injury secondary to pathological fractures
    • Atlanto-axial subluxation
    • Cauda equina syndrome
  • Commonly co-exists with
    • Psoriasis
    • Inflammatory bowel disease

Investigations

  • Full blood count (anaemia of chronic disease)
  • Renal function, liver function (prior to starting NSAIDs or definitive therapy)
  • HLA-B27 (positive in 90% of patients with AS, but not specific)
  • Plan radiograph of the pelvis and spine
    • Scaroilitis
    • Erosions, osteitis at bony prominences
    • Presence of syndesmophytes (bony growths within ligaments) – bamboo spine
  • Magnetic resonance imaging of sacroiliac joints to look for active inflammation
  • Trans-thoracic echocardiogram to assess aortic valve if history and examination suggestive
  • High-resolution computed tomography scan of the lungs to look for apical fibrosis
  • Pulmonary function testing to look for restrictive lung disease

 Management

  • NSAIDs (first-line treatment): continuous use can slow radiographic progression
  • Conventional DMARDs have no role in the treatment of AS (they are not effective)
  • TNF-α inhibitors
    • Indicated in patients who have inadequate response to at least two NSAIDS used for ≥4 weeks each
    • Choices: etanercept, adaliumumab, golimumab, infliximab
    • > 60% response rate
    • May switch to a different TNF-α inhibitor if response to the first decreases
    • Reduces radiographic progression of AS
  • Rituximab (anti-CD20)
    • May have some efficacy in TNF-α naïve patients
    • Currently role in AS is unclear
  • Newer targets
    • Anti-IL12/23: ustekinumab
    • Anti-IL17: secukinumab

This Is A Custom Widget

This Sliding Bar can be switched on or off in theme options, and can take any widget you throw at it or even fill it with your custom HTML Code. Its perfect for grabbing the attention of your viewers. Choose between 1, 2, 3 or 4 columns, set the background color, widget divider color, activate transparency, a top border or fully disable it on desktop and mobile.

This Is A Custom Widget

This Sliding Bar can be switched on or off in theme options, and can take any widget you throw at it or even fill it with your custom HTML Code. Its perfect for grabbing the attention of your viewers. Choose between 1, 2, 3 or 4 columns, set the background color, widget divider color, activate transparency, a top border or fully disable it on desktop and mobile.