Ankylosing Spondylitis

Question 1

Define ankylosing spondylitis

Answer 1

Seronegative spondyloarthropathy: chronic progressive inflammatory arthropathy
predominantly affecting spine and sacroiliac joints

Question 2

What are the causes/risk factors of ankylosing spondylitis?

Answer 2

Unknown aetiology (?infective trigger ?antigen cross-reactivity)
Persistent inflammation and cartilage erosion -> ossification and vertebral fusion
• Family history
• HLA-B27 positive
• Psoriasis
• IBD

Question 3

What are the symptoms of ankylosing spondylitis?

Answer 3

• Early morning stiffness (lower back and buttocks; improves with exercise)
• Progressive back pain
• Achilles tendonitis
• Plantar fasciitis (enthesitis) – heel pain
• Fatigue/sleep disturbance
• Dyspnoea (reduced chest expansion)

Question 4

What are the signs of ankylosing spondylitis?

Answer 4

• Sacroiliac joint tenderness
• Spinal kyphosis
• Loss of lumbar lordosis (bamboo spine)
• Decreased range of spinal movement
• Schober’s test
• Anterior uveitis (red eye)
• Aortic regurgitation

Question 5

What investigations are carried out for ankylosing spondylitis?

Answer 5

• FBC - ACD
• Antibodies - negative –seronegative arthropathy.
• ESR/ CRP - may be elevated; used to monitor disease progression.
• HLA-B27 - positive; may aid in diagnosis but isn’t essential.
• X-Rays - anteroposterior and lateral radiographs of spine: bamboo spine may be seen
anteroposterior radiographs of the SI joints: Symmetrical blurring of joint margins. Later there are erosions, sclerosis and SI joint fusion
• CXR - to look for association with apical fibrosis.
• MRI - bone marrow oedema on T2 is used to show active inflammation