Spondyloarthropathies - Ankylosing spondylitis

Question 1

Definition

Answer 1

Autoimmune inflammatory condition mainly affecting the spine that causes
progressive asymmetrical stiffness + pain.
- Abnormal stiffening of joints (sacroiliac and vertebral)
- Part of the seronegative spondyloarthropathies relating to the HLA B27 gene

Question 2

General features (SPINEACHE)

Answer 2

Sausage fingers (DACTYLITIS)
Psoriasis
Inflammatory back pain
NSAIDS - good response
Enthesis (plantar fasciitis, inflamed heel tendon)
Arthritis
Crohn’s or colitis
HLA B27
Eyes -> UVEITIS

Question 3

Epidemiology

Answer 3

Young < 45 years
Males

Question 4

Risk Factors

Answer 4

Family history: 90% of AS patients show HLA-B27 positivity

Question 5

Pathophysiology

Answer 5

Syndesmophytes (vertebral abnormal bony growth) replace spinal bone damaged by inflammation = decreased mobility
The key joints affected = the sacroiliac joints + joints of the vertebral column. The inflammation causes pain and stiffness in these joints. Can progress to fusion of the spine and sacroiliac joints. Fusion of the spine leads to the classical “bamboo spine” finding on spinal x-ray.
Also causes inflamed tendons, eye, fingers

Question 6

Signs

Answer 6

• Pain in the buttock or along the axial spine
• Reduced lumbar flexion when a patient tries to touch their toes when standing (Schober’s test) and loss of lumbar lordosis
• Reduced chest expansion
• Asymmetrical peripheral joint pain affecting joints (oligoarthritis)
• Anterior uveitis

Question 7

Symptoms

Answer 7

Back pain
- Lower back
- Sacroiliac pain
Reduced spinal movement
Dyspnoea: cases of costochondral involvement
Peripheral arthritis + dactylitis (swelling of a finger or toe)
Painful red eye

Question 8

Systemic symptoms

Answer 8

• Weight loss + fatigue
• Chest pain = costovertebral + costosternal joints
• Enthesitis = inflammation of entheses = where tendon or ligaments insert into bone = plantar fasciitis + Achilles tendonitis
• Dactylitis is inflammation in a finger or toe
• Anaemia
• Anterior uveitis
• Aortitis is inflammation of the aorta
• Heart block = fibrosis of the heart’s conductive system
• Restrictive lung disease = by restricted chest wall movement
• Inflammatory bowel disease is a condition associated with AS

Question 9

Pattern of pain

Answer 9

• Pain is worse with rest + improves with movement
• Pain is worse at night + in the morning + may wake them from sleep
• It takes 30 mins from the stiffness to improve in the morning + progressively better with actively throughout the day
• Symptoms can fluctuate with flares of worsening symptoms + other periods where symptoms improve

Question 10

Diagnosis

Answer 10

FIRST LINE =
- Inflammatory markers: CRP + ESR may be raised
- Spinal X-ray:
= Bamboo spine
= Squaring of vertebral bodies
= Subchondral sclerosis + erosions
= Syndesmophytes (bone growth where ligaments inset into bone in intervertebral joints)
= Ossification of ligaments discs + joints
= Fusion of the facet, sacroiliac + costovertebral joints
- MRI:
= show bone marrow oedema early in the disease before there are any x-ray changes
HLA-B27 genetic testing = NOT DIAGNOSTIC = Present in 90% of patients and 10% of normal people

Question 11

Treatment

Answer 11

FIRST LINE = disease and symptom management
- Symptom: NSAIDS (FL DRUG)
- regular exercise for back pain
- corticosteroids injections = treat flares
If NSAIDs ineffective or not tolerated
- Anti-TNF-a agents = ADALIMUMAB, ETANERCEPT, INFLIXIMAB
* DMARDS not routinely used to treat axial inflammation but SULFASALAZINE or METHOTREXATE may be used in peripheral joint involvement *
SECOND LINE = Surgical = aggressive disease who have a misaligned, fused spine may require surgical intervention

Question 12

Complications

Answer 12

Osteoporosis = bisphosphonates
Spinal fractures
Ischaemic heart disease: associated with increased risk of cardiovascular mortality
Cauda equina syndrome and neurological involvement
Apical fibrosis and pulmonary involvement: less common, may present with dyspnoea