Seronegative arthritis Flashcards
(32 cards)
What are the types of seronegative spondylarthropathies?
- Psoriatic arthritis
- Enteropathic arthritis
- Ankylosing spondylitis
- Reactive arthritis
Which allelle are seronegative spondyarthropathies associated with?
HLA-B27
What is psoriatic arthritis?
Inflammatory arthritis associated with psoriasis
Epidemiology of psoriatic arthritis
- 10-20% of patients with psoriasis
- usually within 10 years of skin changes
What are the patterns of psoriatic arthritis?
- Symmetrical polyarthritis
- Asymmetrical oligoarthritis
- Spondyloarthritis
- Distal arthritis
- Arthritis mutilans
Describe symmetrical polyarthritis
- Presents similarly to rheumatoid
- ≥ 5 joints affected
- More common in women
- Hands, wrists, ankles, distal inter-phalangal joints
- MCP less commonly affects (unlike rheumatoid)
Describe asymmetrical oligoarthritis
- ≤ 4 joints affected
- Typically affects the hands and feet
Describe spondyloarthritis
Primarily affects the spine and sacroiliac joints
Descibe distal arthritis
- Affects distal interphalangeal joints of hands and/or feet
- Usually occurs alongside other types
Describe arthritis mutilans
- Most severe and least common form
- Deforming and destructive subtype
- Telescoping and flail digits (due to osteolysis of bone around joint)
General symptoms seen in an inflammatory arthropathy
Joint pain and stiffness that is worse in the morning and improves on movement.
Signs of psoriatic arthritis
- Psoriasis: psoriatic lesions, scalp and nail symptoms (nail pitting, oncholysis)
- Joint tenderness, warmth and reduced range of movement
- Dactylitis: swelling of an entire digit
- Enthesitis: inflammation of the plantar fascia and Achilles’ tendon
What is oncholysis?
Seperation of the nail from the nail bed
What is dactylitis?
Swelling of the entire finger or toe
What is enthesitis?
Inflammation of the entheses, which are the points of insertion of tendons into bone.
Other associations with psoriatic arthritis
- Eye disease (conjunctivitis and anterior uveitis)
- Aortitis (inflammation of the aorta)
- Amyloidosis
Which criteria must be fulfilled to diagnose psoriatic arthritis?
CASPAR criteria
A diagnosis of psoriatic arthritis can be made if the patient scores > 2 points on the following:
- History of psoriasis: 2 points
- Psoriatic nail changes: 1 point
- Rheumatoid factor negative: 1 point
- History of dactylitis: 1 point
- Radiologicl evidence (juxta-articular periostitis): 1 point
What X-ray changes are seen for psoriatic arthritis?
- Periostitis is inflammation of the periosteum causing a thickened and irregular outline of the bone
- Ankylosis is where bones joining together causing joint stiffening
- Osteolysis is destruction of bone
- Dactylitis is inflammation of the whole digit and appears on the xray as soft tissue swelling
- Pencil-in-cup appearance
Management of psoriatic arthritis
All patients require referal to a rheumatologist
Mild disease:
- NSAIDs and physiotherapy: first-line options to reduce inflammation, improve range of motion and strengthen muscles
- Intra-articular steroids
Progressive disease:
- Disease-modifying antirheumatic drugs (DMARDs): used in addition to the above for patients with polyarthritis or joint erosions. Methotrexate is first-line, whilst sulfasalazine is used in patients who are intolerant to methotrexate
- Biologic agents: TNF-α inhibitors, such as etanercept or infliximab, should be considered in patients with oligoarthritis or polyarthritis following the failure of 2 DMARDs
Key joints affected in ankylosing spondylits
- Sacroiliac joints
- Vertebral column
How many patients with ankylosing spondylitis have the HLA B27 gene?
How many patients with the HLA B27 gene develop ankylosing spondylitis?
90%
2%
Typical exam presentation of ankylosing spondylitis
- Young adult male
- Late teens/twenties
- Symptoms come on slowly over > 3 months
- Low back pain and stiffness + Sacroiliac pain
- Worse with rest
- Impoves with movement
- > 30 minutes morning stiffness
Describe Schober’s test
Find the L5 vertebrae. Mark a point 10cm above L5 vertebrae and 5cm below.
Ask patient to bend forward as far as they can. Measure the distance between the points.
If the distance is <20cm this indicateds a restiction in lumbar movement and supports a diagnosis of ankylosing spondylitis.
Investigations for ankylosing spondylitis
- Inflammatory markers: CRP↑ ESR↑
- Genetic test: HLA B27
- X-ray: spine and sacrum
- If X-ray normal: MRI spine may show early changes: bone marrow oedema
