Ankylosing Spondylitis Flashcards
What is ankylosing spondylitis?
A chronic inflammatory condition that affects the axial and sacroilial joints causing stiffness & pain. It is a seronegative spondyloarthropathy, associated with HLA-B27 gene.
What is the pathophysiology?
Interaction between HLA-B27 and T cell response, leading to an increased conc of T cells, macrophages and inflammatory cytokines. This fuels an immune response that produces the hallmarks of AS.
What are the risk factors?
- Gender = MALE (3:1)
- Age = 20-30 yo
- Family history (esp. w an immediate family member)
What are the symptoms?
- Bilateral pain (Lower back, buttock, chest wall, thoracic)
- Worse at night
- Improved by getting up
- Stiffness
- Worse in morning
- Improved with exercise
- Arthritis of other joints (usually hips & knees)
- Fatigue
What signs are seen on examination?
- Loss of lumbar lordosis
- Exaggerated thoracic kyphosis
- Schober’s test +ve
- Mark skin 10cm above & 5cm below PSIS
- Bend forward w straight legs
- Distance increase <20cm = +ve result
- Reduced lateral flexion
- Reduced chest expansion
- Tragus-wall distance increase
What are some extra-articular manifestations of Ankylosing Spondylitis?
ALL THE A’s!
Anterior Uveitis
Aortic incompetence
AV block
Apical lung fibrosis
Amyloidosis
Also… Lesions on skin / mucous membranes
- e.g IBD, psoriasis, etc.
What investigations are useful in diagnosing ankylosing spondylitis? & the expected results?
Inflammatory markers
- CRP
- ESR
- Can be raised or normal.
HLA-B27
Not used alone to form diagnosis - present in 10% of population
Imaging
- MRI of spine and SI joints
DIAGNOSIS CONFIRMED BY PRESENCE OF HLA-B27 & +VE IMAGING FINDINGS
What is the sign seen here?
Bamboo Spine
Occurs due to:
- Ossification of the outer fibres of the annulus fibrosus
- Formation of marginal syndesmophytes between adjoining vertebral bodies
XR can also be used to investigate but MRI has superseded it. Why?
Because MRI is more sensitive so can show signs of early disease. Whereas XR shows late signs of disease.
What is the non-pharmaceutical management?
- Encourage regular exercise such as swimming.
- Physiotherapy
What mneumonic details features of inflammatory back pain?
IPAIN
- Insidious onset
- Pain at night
- Age of onset <40
- Improvment with exercise / getting up
- No improvement with rest
What is the pharmaceutical management?
- NSAIDs
- TNF inhibitors
- Methotrexate /
- IL-17 inhibitors
What are some more complications of AS?
- Fusion of the spinal column leading to reduced spinal mobility.
- Joint damage
- Anterior uveitis
- Can lead to blindness
- Osteoporosis & spinal fractures
- CVD
- Cauda equina syndrome (rare)
