Ankylosing Spondylitis (AS) Flashcards
What is Ankylosing Spondylitis (AS)?
Chronic inflammatory disease that primarily affects the axial skeleton, leading to partial or complete fusion and rigidity of the spine
What is the genetic predisposition associated with AS?
HLA B27 gene, found in approximately 90% of individuals with AS
What are the common symptoms of AS?
(1) Gradual onset of dull, axial pain (neck, cervical, thoracic, lumbar)
(2) Morning stiffness lasting >30 minutes that improves with activity
(3) Pain in peripheral joints (knee, shoulder, hip) - rare
(4) Weight loss, fever, and fatigue
What is the typical age of onset for AS?
20-40 years
What physical sign tests can be used for AS?
- Schober’s test
= Measures lumbar spine flexion. A normal increase is >20 cm. - Occiput-to-wall distance
= Normal is 0, which measures the spine’s flexibility. - Reduced chest expansion is also common
What is the hallmark X-ray finding in AS?
“Bamboo spine”
What imaging is used to detect early changes in Ankylosing Spondylitis?
MRI
What blood tests are commonly raised in Ankylosing Spondylitis?
- Raised inflammatory markers: ESR, CRP
- Positive HLA-B27 gene test
What is the ASAS classification criteria for axial spondyloarthritis?
For patients with ≥ 3 months of back pain and age of onset <45 years, the criteria include:
(1) Sacroiliitis on imaging, and ≥ 1 SpA feature
OR
(2) HLA-B27 positive and ≥ 2 other SpA features
(inflammatory back pain, arthritis, enthesitis)
What is the first-line pharmacological treatment for Ankylosing Spondylitis?
NSAIDS
What biologic treatments are used in severe Ankylosing Spondylitis?
- Anti-TNF agents
(eg infliximab, adalimumab) - If still unresponsive, consider Secukinumab (anti-IL17)
When is surgery indicated for Ankylosing Spondylitis?
Hip and knee arthritis
Kyphoplasty for severe spinal deformities
Which group of rheumatological diseases is HLA-B27 classically associated with?
Seronegative spondylarthropathies, particularly ankylosing spondylitis
What are the four main seronegative spondyloarthropathies?
Ankylosing spondylitis
Reactive arthritis
Enteropathic arthritis
Psoriatic arthritis
Why are seronegative spondyloarthropathies named as such?
They are antibody negative
A 24-year-old man presents to the GP due to pain and stiffness in his back over the last 3 months. He is in good shape but has been feeling increasingly tired. He lacks the motivation to exercise but finds that on days he exercises, his back is less sore the following day. His past medical history is unremarkable other than an episode of a painful red eye some years ago.
What is the gold standard investigation for the likely diagnosis?
MRI scan
A 27-year-old male presents with 6 months of chronic lower back pain and morning stiffness lasting over 30 minutes. The pain improves with exercise and worsens with rest. He has no history of trauma.
Explain why an X-ray of the sacroiliac joints is the best first-line imaging investigation.
Since symptoms have been present for over 3 months, an X-ray is the first-line investigation to look for sacroiliitis (joint sclerosis, erosions, fusion).
If the X-ray is normal but suspicion remains high, an MRI would be the next step
A 22-year-old female presents with 2 months of inflammatory back pain that wakes her up at night. Her symptoms improve with ibuprofen. Her inflammatory markers (CRP, ESR) are mildly elevated.
What is the most appropriate first-line imaging? and explain why?
Symptoms have been present for less than 3 months, meaning structural damage may not yet be visible on X-ray.
MRI is better for detecting early inflammation
(bone marrow oedema, sacroiliitis) before X-ray changes appear
What investigation is used to detect active inflammation in ankylosing spondylitis?
MRI
A 42-year-old male with a history of Ankylosing Spondylitis presents with progressive weakness in both legs and difficulty controlling his bladder. He also reports numbness in his lower back and buttocks. What is the most appropriate next step in imaging?
Urgent MRI of the spine
= neurological symptoms
What are the neurological symptoms that someone presenting with ankylosing spondylitis would need an urgent MRI for?
leg weakness, bladder dysfunction, or numbness
A 27-year-old man presents to his GP following 3 months of worsening back pain. He finds his mobility is restricted, affecting his hockey playing, but when he does attend practice, his back feels better the following day. He reports that the pain sometimes wakes him up at night and that it improves after taking ibuprofen. He states that his brother has previously been diagnosed with a type of arthritis but is unable to be more specific.
What is the next best initial investigation?
Xray
What must be done before starting infliximab?
Screen for TB
What is the stepwise approach to medication in Ankylosing Spondylitis (AS)?
- NSAIDS
(eg, >ibuprofen, naproxen) - TNF-alpha inhibitors
> (eg, adalimumab, etanercept, infliximab) - IL-17 inhibitors
- DMARDs
A 26 year old man presents to A&E with an acute episode of eye pain. He describes a dull pain with blurred vision and floaters. On examination his eye is red. This is the third episode of acute eye pain (for which he has been given topical corticosteroid eye drops). He denies dry eyes and does not think any foreign body has entered his eye. He does not wear contact lenses. He reports that he takes over-the-counter NSAIDS and paracetamol as he has longstanding back pain. He has alternating buttock pain with stiffness especially in the mornings and he finds the pain to be worse at night. He denies any other joint pain or skin rash.
What is a complication most associated with the likely diagnosis?
Hypopyon
What are the symptoms of anterior uveitis (iritis)?
(1) recurrent eye pain
(2) blurred vision
(3) redness
(4) back pain
(5) morning stiffness
A 31-year-old man presents to the rheumatology clinic with low back pain. He has a hunched posture.
Which features are most suggestive of Ankylosing Spondylitis?
- Morning stiffness lasting > 30 minutes
- Pain at night
- Improves with exercise
- Limited lumbar spine movement
- Hunched posture (kyphosis)
- Previous history of uveitis
- Positive HLA-B27
- Positive family history of AS or related conditions
- Fusion of joints (sacroiliac joints, spine)
- Bamboo spine on X-ray
A 28-year-old man presents to his GP with gradually worsening lower back pain and stiffness for the past six months. He mentions it is worse in the morning and is relieved by exercise. There is no history of trauma.
Given the most likely underlying disease, what is the most appropriate first-line investigation?
Xray pelvis + spine
These develop between vertebrae and contribute to the fusion of the spine (ankylosis), which can lead to the “bamboo spine” appearance on X-ray.
What is this describing?
Syndesmophytes
A 31-year-old man presents to his GP with a red, painful right eye and photophobia. On examination, his right eye is red with a small, irregular pupil.
He is currently also undergoing investigation for prolonged lower back stiffness in the morning and is awaiting an outpatient imaging appointment for pelvic and lumbar X-rays. He has a past medical history of plantar fasciitis.
Given the likely diagnosis, what is the most appropriate management?
Cyclopentolate
