Spondyloarthopathies Flashcards
What are the spondyloarthropathies
Group of related chronic inflammatory conditions.
What do they affect
Axial skeleton
What clinical features do they share? SPONDYLARTHOPIES
- Seronegativity (rheumatoid factor negative)
- HLA-B27 association*
- Axial arthritis - pathology in spine and sacroiliac joints
- Asymmetrical large-joint oligoarthritis or monoarthritis
- Enthesitis - inflammation at the site of insertion of a tendon or ligament into a bone
- Dactylitis - infammation of entire digit e.g. sausage fingers
- Extra-articular manifestations e.g. iritis (inflammation of eye), psoriaform rashes, oral ulcers, aortic valve incompetence, inflammatory bowel disease
What percentage of the UK population have these disease?
Around 5% of the UK population is HLA-B27 positive but most do not have the disease. The chances of developing disease in this group of people is 1 in 4.
Common assosciations with these conditions
- Ankylosing spondylitis - 85-95% of people are HLA-B27+
- Acute anterior uveitis - 50-60% of people are HLA-B27+
- Reactive arthritis - 60-85% of people are HLA-B27+
- Enteric arthropathy - 50-60% of people are HLA-B27+
- Psoriatic arthritis - 60-70% of people are HLA-B27+
Pathology theory
infection triggers an immune response and the infectious agent has peptides very similar to the HLA-B27 molecules so there is an auto-immune response triggered against HLA-B27.
Pneumonic for suspected spondyloarthropathies:
SPINEACHE
SPINEACHE
- Sausage digit (dactylitis)
- Psoriasis
- Inflammatory back pain
- NSAID good response
- Enthesitis (particularly in heel - plantar fasciitis)
- Arthritis
- Crohn’s/Colitis/elevated CRP (can be normal in AS)
- HLA-B27
- Eye (uveitis)
What is Ankylosing spondylitis (AS)
chronic progressive inflammatory arthropathy. Mainly affects the spine and causes progressive stiffness and pain.
What is ankylosis?
abnormal stiffening and immobility of joint due to fusion of bones
Epidemiology of AS
- M>F
- Most commonly presents in late teens/ twenties
- Women present later and are under-diagnosed
- 90% are HLA-B27 positive
RF for AS
- HLA-B27
- Family history of ankylosing spondylitis
Pathophysiology of AS
Lymphocyte and plasma infiltration occurs with local erosion of bone at the attachments of the intervertebral and other ligaments which heals with new bone (syndesmophyte) formation.
Can progress to kyphossi, neck hyperextension and spino-cranial ankylosis
Signs of AS
- Enthesitis - inflammation at point of insertion of tendons and ligaments in bones
- Dactylitis - inflammation of entire digit
- Bamboo spine on x-ray due to fusion of the joints
Typical presentation of AS
Young teen or male on 20’s
-Pain and stiffness of joints
- Lower back pain
- Sacroiliac pain (buttock region)
- Pain worst at night and in the morning (>30 minutes of stiffness in morning)
- Pain worst with rest and improves with movement
- Systemic symptoms e.g. weight loss and fatigue
- Chest pain - related to costovertebral and costosternal joints
Investigations for AS
- FBC - normocytic anaemia
- CRP and ESR - elevated
- Genetic testing - HLA-B27?
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X-ray - of spine and sacrum
- MRI of spine
Schober’s test
General examination of spine (especially lumbar spine) to assess mobility.
Patient stands straight. Find L5 vertebrae and mark a point 10cm above this and 5cm below. Ask patient to bend forward, and measure distance between two points.
If distance between the two points is less than 20cm, this indicates restriction in the lumbar movements.
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Differential diagnosis for AS
- Osteoarthritis
- Psoriatic arthritis
- Reactive arthritis
- Vertebral fracture
Medical management (IN ORDER) of AS
- NSAIDs e.g. ibuprofen or naproxen (2-4 weeks. If no improvement, switch to another NSAID)
- Steroids - used during flares (oral, IM or directly into joints)
- Anti-TNF e.g. etanercept or monoclonal antibodies against TNF e.g. infliximab, adalimumab
- Monoclonal antibodies targeting IL-7 - e.g. secukinumab
Conservative measures for AS
Physiotherapy
Avoid smoking
Bisphosphates
Treatment for complications
Surgery
Complications for AS
- Vertebral fractures
- Osteoporosis
- Anaemia
- Anterior uveitis (eye inflammation)
- Aortitis (inflammation of aorta)
- Heart block - fibrosis of the heart conduction system
- Restrictive lung disease - due to restrictive movement of chest wall
- Pulmonary fibrosis - especially upper lobes of lungs
- Inflammatory bowel disease