Ankylosing Spondylitis Flashcards
What type of disease in ankylosing spondylitis (AS)?
seronegative spondyloarthropathy
What other diseases are part of the Group of Sponylorarthritides?
- Psoriatic arthritis
- Enteropathic arthritis
- Reactive arthritis
What gene is AS associated with?
HLA-B27
What is AS?
chronic progressive inflammatory arthropathy lead to radiological change in spine and sacroiliac joints
What are causes of AS?
- HLA-B27 gene: in 90%
- FHx
- Male
- ERAP-1 and IL-23R gene
What is classic epid of AS?
- Age of onset <40 (late teens and early 20s) years and back pain lasting >3 months
- Male
- Prevelance: 0.25-1%
What are classic symptoms and signs of AS?
- Inflammatory bank pain
- Iritisi/uveitis
- Enthesitis
- Fatigue
- Sleep disturbance
- Kyphosis
- Progressive loss of spinal movement
What is the back pain like in AS?
- insidious onset
- worse in morning
3, improve with exercise
What are possible DDx for AS?
- Osteoarthritis
- Diffuse idiopathic skeletal hyperostosis (DISH)
- Psoratic arthritis
- Reactive arthritis
- Infection
- Bony metastases
What imaging is used for AS?
- MRI back
2. Pelvic X ray
Why do you do a MRI back?
detection of active inflammation and destructive changes
What would MRI back show in AS?
- Vertebral syndesmophytes are characteristic (T11-L1 initially)
- Bony proliferations due to enthesitisisbetween ligament and vertebrae, these fuse with the vertebral body above causing ankylosis
- bone marrow oedema (early)
What bloods are done and what do they show in AS?
- FBC: normocytic anaemia
- ESR: high
- CRP: high
- HLA-b27 positive
- Rh negative
What is 1st line treatment for AS?
NSAID e.g. naproxen 500mg 2x daily and exercise
What else would be added to the treatment of AS?
- Analgesia
- Intra-articular corticosteroid injection (if local intra-articular inflammation)
- Sulfasalazine or methotrexate (if peripheral joint involvement)
When may a TNF-alpha inhibitor and physiotherapy be used for AS?
if enthesitis and/or peripheral arthritis
What are possible complications for AS?
- Osteoporosis
- Cardiac involvement
- Hip involvement
- Iritis
- Pulmonary involvement
- Neurological involvement
When is the prognosis worse for AS?
- ESR>30
2, onset <16yrs - early hip involvement
- poor response to NSAIDs
What is seen the pathogonominic radiographic feature seen in AS?
bamboo spine
What does the inflammation start in AS?
- at sites of attachment of ligaments to the vertebral bodies (first in lumbar region)
- progresses to cervical and thoracic spine
- Potentially infective triggers?
What is enthestisis?
- plantar fasciitis
- Achilles’ tendonitis
- dactylitis
What is the extrarticular manifestations of AS?
- Anterior uveitis (40%)
- Apical lung fibrosis
- Aortic regurgitation
- Psoriasis, IBD Sx
What is needed for diagnosis of AS?
> 3 months inflammatory back pain, with sacroiliac joints + axial spine affected > peripheral joints
What is the defintion of AS?
Chronic, progressive inflammatory arthropathy of axial skeleton
+ Peripheral joints, entheses (tendon/ligament attachments) & extra-articular sites
What are the special clinical tests for AS?
- (Modified) Schober’s test
- Tragus to wall
- Stress test
What is modified schober’s test?
- tests lumbar motility
- Mark 2 points: 10cm above L5, 5cm below
- Patients bends forward
- Point-point distance increases <5cm means AS
What is tragus to wall test?
- Physiological <15cm
- Increased in AS
What happens in Stress Tests e.g., Gaenslen’s?
Sacroliac joint pain
What would XR show in AS?
- sacroiliitis (early)
2. syndesmophytes and bamboo spine (late)
What test results show AS?
- Schober’s test <20cm total
- Bloods: Raised ESR/CRP, ACD, Rh negative
- Genetic test: HLA B27 +ve 90-95%
- XR: sacroiliitis (early), syndesmophytes & bamboo spine (late)
- MRI: bone marrow oedema (early)
- Lung function tests: impairment from kyphosis
What medication is used in AS?
- NSAIDs
- Steroids during flares – oral, IM or intraarticular
- Anti-TNF
- Secukinumab – IL17 mAb
- Physiotherapty + smoking cessation + bisphosphonates for osteoporosis
- ?Surgery
What is the grading used for sarcoillitis?
New York
What is the New York grading for scaroillits?
- grade 0: normal
- grade I: suspicious changes (some blurring of the joint margins)
- grade II: minimum abnormality (small localised areas with erosion or sclerosis, with no alteration in the joint width)
- grade III: unequivocal abnormality (moderate or advanced sacroiliitis with erosions, evidence of sclerosis, widening, narrowing, or partial ankylosis)
- grade IV: severe abnormality (complete ankylosis)
What are late changes in AS?
- Kyphosis
- Loss of lumbar lordosis
- Neck extension
