Axial Spondyloarthritis and Psoriatic Arthritis Flashcards
How is axial spondyloarthritis classified?
3/12 of inflammatory back pain with onset at age than less than 45 years plus either sacrolititis on imaging and >1 SpA feature OR HLA-B27 positive and > 2 other SpA features
What are the SpA features?
inflammatory back pain arthritis enthesitis uveitis dactylitis psoriasis crohn's/colitis good response to NSAIDs family history HLA-B27 elevated CRP
How is peripheral spondyloarthritis classified?
peripheral arthritis or enthesitis or dactylitis PLUS at least one of (uveitis, psoriais, colitis, preceding infection, HLA-B27, sacrolitis on imaging) OR at least two of (arthritis, enthesitis, dactylitis, inflammatory back pain, FHx)
What conditions are classified as spondyloarhtritides?
Ankylosing spondylitis, undifferentiated SpA, Juvenile SpA, arthritis associated with UC/crohn’s, reactive arthritis, acute anterior uveitis, psoriatic arthritis
What is inflammatory back pain?
Back pain that occurs at age of less than 40 with a gradual onset, improvement with exercise, pain at night that improves when getting up
Which genes are involved in axSpAs?
HLA-B27, HLA-B40, ERAP1
What is a characteristic feature of the spondyloarthropathies?
bone remodelling occurs as well as damage
What are the clinical features of axial spondyloarthritis?
inflammatory back pain, alternating buttock pain, restriction in spinal movement, extra axial MSK features, extra articular features
What are the extra axial MSK features of axial spondyloarthritis?
Peripheral arthritis - in an asymmetric oligoarthritis pattern, and enthesitis
What are the extra articular features of axial spondyloarthritis?
anterior uveitis, IBD, psoriasis, apical fibrosis, aortic regurgitation
How common is axial spondyloarthritis?
0.5-1% of population
When is onset of symptoms of axial spondyloarthritis?
3rd decade of life
What percentage of people with the HLA-B27 gene will develop an axial spondyloarhtitis?
5%
What investigations should be done when axial spondyloarthritis is suspected?
HLA-B27, inflammatory markers, XR (sacro iliac joints, cervical and thoraco-lumbar spine), MRI
What percentage of people with AS are positive for HLA-B27?
90%
What is the difference between non radiographic axial spondyloarthritis and ankylosing spondylitis?
they are a spectrum of the same disease - non radiographic patients go on to develop AS over time (after 20 years 85% will have developed AS), patients have same levels of pain however patients with AS have more imapired spinal mobility and chest expansion
What does sacrolitis look like on plain XR?
normal in early disease, early changes: erosions, sclerosis at margins, later: pseudo-widening, last: joint space narrowing progressing to ankylosis
What does the spine look like on plain XR in ank spond?
squaring of the vertebrae, romanus lesion (shiny corner), syndesmophyte. In late stages can have fractures and fusion of facet joints
What are the features of sacro-iliitis on MRI?
active inflammation (subchondral bone marrow oedema), synovitis, enthesitis, post inflammatory lesions (erosions, sclerosis, ankylosis, fatty lesions)
What are the features in a spine MRI in axial spondyloarthritis?
bone marrow oedema at vertebral corners, erosions, spondylodiscitis
Which MRI sequence is best for visualising subchondral bone marrow oedema?
STIR sequence
What predicts radiographic progression?
active inflammation and smoking
What is first line therapy for axial spondyloarhtiritis?
NSAIDs and non pharmacologics e.g. exercise
Are NSAIDs disease modifying?
yes
