Ankylosing spondylitis Flashcards
What is ankylosing spondylitis (AS)?
Ankylosing spondylitis is an inflammatory condition primarily affecting the axial skeleton (spine and sacroiliac joints), causing progressive stiffness and pain. It is part of the seronegative spondyloarthropathy group of conditions.
What is the main affected area in ankylosing spondylitis?
The main affected areas are the sacroiliac joints and the vertebral column joints, which can progress to fusion of these joints.
What gene is strongly associated with ankylosing spondylitis?
The HLA-B27 gene is strongly linked with ankylosing spondylitis. Around 90% of AS patients have this gene, although less than 10% of those with the gene will develop AS.
Who is most commonly affected by ankylosing spondylitis?
AS typically presents in young adult males in their 20s but can affect both men and women.
What are the main presenting features of ankylosing spondylitis?
The main features include:
* Pain and stiffness in the lower back
* Sacroiliac pain (in the buttock region)
* Pain and stiffness that worsens with rest and improves with movement
* Morning stiffness lasting at least 30 minutes
What additional symptoms and problems may occur in ankylosing spondylitis?
Additional symptoms may include:
* Chest pain (due to costovertebral and sternocostal joint involvement)
* Enthesitis (inflammation at tendon or ligament insertion sites)
* Dactylitis (inflammation of the entire finger)
* Vertebral fractures (sudden neck or back pain)
* Shortness of breath due to restricted chest wall movement
What is the mnemonic to remember key associations with ankylosing spondylitis?
The 5 As mnemonic:
* A – Anterior uveitis
* A – Aortic regurgitation
* A – Atrioventricular block (heart block)
* A – Apical lung fibrosis
* A – Anaemia of chronic disease
How is spinal mobility assessed in ankylosing spondylitis?
Schober’s test assesses spinal mobility by measuring the change in distance between two points on the spine as the patient bends forward. A length of less than 20cm suggests restriction in lumbar movement, supporting a diagnosis of AS.
What investigations are used in the diagnosis of ankylosing spondylitis?
Investigations include:
* Inflammatory markers (e.g., CRP, ESR) may be elevated
* HLA-B27 genetic testing
* X-ray of the spine and sacrum
* MRI of the spine can show bone marrow edema early in the disease
What are the typical X-ray changes seen in ankylosing spondylitis?
Typical X-ray changes include:
* Bamboo spine (fusion of the sacroiliac and spinal joints)
* Squaring of the vertebral bodies
* Subchondral sclerosis and erosions
* Syndesmophytes (bone growth at ligament insertions)
* Ossification of ligaments, discs, and joints
What is the goal of treatment for ankylosing spondylitis?
The aim of treatment is to control symptoms and preserve function.
What are the treatment options for ankylosing spondylitis?
Treatment options include:
* First-line: Non-steroidal anti-inflammatory drugs (NSAIDs)
* Second-line: Anti-TNF medications (e.g., adalimumab, etanercept, infliximab)
* Third-line: Secukinumab, ixekizumab (monoclonal antibodies targeting interleukin-17), or upadacitinib (JAK inhibitor)
* Intra-articular steroid injections for specific joints
What additional management strategies are used for ankylosing spondylitis?
Additional management strategies include:
* Physiotherapy
* Regular exercise and mobilization
* Avoiding smoking
* Bisphosphonates for osteoporosis
* Surgery for severe joint deformity
