Seronegative arthritis Flashcards
What are the spondyloarthritides and how do they present?
- A group of arthritides that have a negative rheumatoid factor (Seronegative)
- They may be associated with HLA-B27 but this is not diagnostic
- Usually they are an assymmetric arthritis - more common in larger joints
- Usually involve the axial skeleton (spine)
- Extra-articular features - uveitis, IBD
What is the hallmark sign of axial involvement in these arthritides?
Sacroiliitis - painful condition caused by inflammation of either 1 or 2 of the sacro-iliac joints (may be unilateral or bilateral). It may not be present in all types of spondyloarthritis.
In order to diagnose Ankylosing spondylitis what should a patient have?
Bilateral sacroiliitis
Different types of spondyloathritis
- Ankylosing Spondylitis – key one – presents with inflammatory back pain
- Psoriatic arthritis - patients with psoriasis have 10% risk of developing inflammatory arthritis
- Bowel related arthritis (Crohn’s, UC)
- Reactive arthritis - inflammatory arthritis triggered by various pathogens
- Juvenile ankylosing spondylitis
What is Ankylosing Spondylitis?
- Chronic inflammatory rheumatic disorder that involves axial skeleton and Enthesitis (inflammation where a tendon or ligament attach to bone)
- Onset during 20-30s is more common
- Males > Females
- 80-95% of patients with AS have HLA-B27 gene so there is thought to be a potential genetic cause
Name 4 measurements/tests that might be done in clinic to assess the severity of spinal restriction of a patient with AS
- Modified Schober test - assesses the amount of lumbar flexion (fingers on back and ask patient to bend forward)
- Lateral spinal flexion
- Occiput to wall and Tragus to wall
- Cervical rotation
Modified Schober test
Patient stands erect and the doctor marks an imaginary line connecting both posterior superior iliac spines
A next mark is placed 10 cm above
The patient then bends forward fully and the doctor should now measure the difference between the two makrs
If the distance increases to 15 cm this is normal, anything less is abnormal
Lateral spinal flexion test
Patient stands with their heels and back resting against the wall and arms by their side. No flexion in the knees and no bending forward.
A mark should be placed on the thigh where the tip of the fingers touch the thigh and as the patient bends to the side you should then mark where the fingers lie.
Occiput to wall and tragus to wall test
See the amount of thoracic kyphosis there is
Cervical rotation test
What are the clinical features of AS?
- Inflammatory back pain - tends to give severe stiffness (particularly in morning) which is better with activity (like R.A)
- Limitation of movements of lumbar spine in antero-posterior as well as lateral planes
- Limitation of chest expansion
- Bilateral sacroiliitis - picked up earlier on MRI than x-ray
Look
Image shows MRI scan of the sacroiliac joint
Brightness = oedema around the sacroiliac joint
What cardiac features are related with ankylosing spondylitis?
Aortic incompetence, heart block
How is ankylosing spondylitis managed?
Similar treatment to R.A:
- Physiotherapy is really important - maintain posture and stretchability of spine
- NSAIDs for inflammation
- DMARDs - Sulfasalazine
- Biologics such as Anti-TNF or Anti-IL-17
- Treatment of osteoporosis - depsite AS being a bone forming disease patients are still at risk of osteoporosis
- Surgery - joint replacements and spinal surgery
Psoriatic arthritis
- A form of arthritis that affects some people who have psoriasis
- It commonly involes the distal interphalangeal joints (DIP)
- Tends to be a symmetric polyarthritis
- The severity of joint disease does not correlate to extent of skin disease
