Seronegative Arthritis Flashcards
What is psoriatic arthritis?
Chronic seronegative inflammatory arthritis associated with psoriasis
What percentage of patients with psoriasis develop psoriatic arthritis?
10-20% of patients with psoriasis and usually occurs within 10 years of developing the skin changes. It ty
What causes psoriatic arthritis?
Genetic
- HLA-B27
What are the recognised patterns of psoriatic arthritis?
Symmetrical polyarthritis, presents similarly to RA
Asymmetrical pauciarthritis, affecting mainly the digits and feet
Arthritis mutilans, severe form occuring at phalanxes
Spondylitic pattern, more common in men
What is arthritis mutilans?
Most severe form of psoriatic arthritis occurring in the phalanxes.
Destructionof the bones leads to progressive shortening of the digit. The skin then folds as the digit shortens giving an appearance that is often called a ‘telescopic finger’
How does psoriatic arthritis present?
Psoariasis plaques
Pitting of nails
Onycholysis/nail separation from nail bed
Arthritis, particuarly of DIP joints
Brown discolouration of nail
Dactylitis
What xray changes are seen in psoriatic arthritis?
Periostitis, thickened and irregular outline of the bone
Ankylosis
Osteolysis/destruction of bone
Dactylitis, inflammation of the whole digit that appears on the xray as soft tissue swelling
Plantar spur
Pencil-in-cup appearance, due to central erosions of the bone beside the joints
How is psoriatic arthritis managed?
NSAIDS
DMARDS
Anti-TNF
Ustekinumab is last lin, a monoclonal antibody that targets interleukin 12 and 23
What conditions are associated with psoriatic arthritis?
Conjunctivitis and anterior uveitis
Aortitis
Amyloidosis
How are patients with psoriasis screened for psoriatic arthritis?
Psoriasis Epidemiological Screening Tool (PEST)
This involves several questions asking about joint pain, swelling, a history of arthritis and nail pitting. A high score triggers a referral to a rheumatologist.
What is ankylosing spondylitis?
Chronic seronegative arthritis in which there is autoimmune inflammation of the spine (most commonly, although other bones can be involved) causing fusion (ankylosis)
What sex is more likely to be affected by ankylosing spondylitis?
M>F
What is the most common age of onset of ankylosing spondylitis?
20s-30s
What causes ankylosing spondylitis?
Genetic
- Associated with HLA-B27 allele
Connection with HIV
What gene is ankylosing spondylitis associated with?
HLA-B27, approx 90% of patients have this gene
How does ankylosing spondylitis present?
Symptoms develop gradually, over approx 3 months
Pain
- Can radiate to buttocks
- Lower back and sacroiliac joints, usually first to be affected
- Worsens at night/morning, takes approx 30 minutes to improve in morning
- Improves with activity
Stiffness
- Worsens in morning and after periods of rest
Decreased range of movement of lumbar spine
- Reduced lateral flexion
- Reduced forward flexion/schobers test
- Reduced chest expansion
Question mark posture, due to increased kyphosis
Tenderness of sacro-iliac joints
What are the systemic signs of ankylosing spondylitis?
Uveitis
IBD
Aortic incompetence
Heart block
Enthesitis
Weight loss
Fatigue
Pulmonary Fibrosis
Amyloidosis
Describe Schobers test
Have the patient stand straight and find the L5 vertebrae. Mark a point 10cm above and 5cm below this point (15cm apart from each other)
Ask the patient to bend forward as far as they can and measure the distance between the points
If the distance with them bending forwards is less than 20cm, this indicates a restriction in lumbar movement and will help support a diagnosis of ankylosing spondylitis
What investigations are used in ankylosing spondylitis diagnosis?
>CRP and ESR
HLA-B27
Pelvic x ray for diagnosis
MRI of spine, shows bone marrow oedema before xray changes
What X-Ray signs are seen in ankylosing spondylitis?
Collectively known as bambo spine
X-Ray changes not noticeable until severe disease
Symmetrical blurring and narrowing of sacroiliac joint
Fusion and squaring of vertebral bodies
Ossification of spinal ligament/syndesmophytes
Subchondral sclerosis and erosions of sacroilliac joint
How is ankylosing spondylitis managed?
Physiotherapy/spinal exercises
Avoid smoking
NSAIDS
- For pain, if no relief in 2-4 weeks of maximum dose consider switching NSAID
Steroids, used during flares to control symptoms
Anti-TNF medications/monoclonal antibodies, used in failure to respond to NSAIDS
Surgery
- Joint replacements
- Spinal surgery
What is the first line management of ankylosing spondylitis?
Exercise regime and NSAIDS
When should anti TNF alpha inhibitors be initiated in ankylosing spondylitis management?
Should be used in axial ankylosing spondylitis that has failed on 2 different NSAIDS and meets criteria for active disease on 2 occasions 12 weeks apart
Give examples of TNF-alpha blockers
Infliximab
Etanercept
