Seronegative arthritis

Question 1

What are the types of seronegative spondylarthropathies?

Answer 1

• Psoriatic arthritis
• Enteropathic arthritis
• Ankylosing spondylitis
• Reactive arthritis

Question 2

Which allelle are seronegative spondyarthropathies associated with?

Answer 2

HLA-B27

Question 3

What is psoriatic arthritis?

Answer 3

Inflammatory arthritis associated with psoriasis

Question 4

Epidemiology of psoriatic arthritis

Answer 4

• 10-20% of patients with psoriasis
• usually within 10 years of skin changes

Question 5

What are the patterns of psoriatic arthritis?

Answer 5

1. Symmetrical polyarthritis
2. Asymmetrical oligoarthritis
3. Spondyloarthritis
4. Distal arthritis
5. Arthritis mutilans

Question 6

Describe symmetrical polyarthritis

Answer 6

• Presents similarly to rheumatoid
• ≥ 5 joints affected
• More common in women
• Hands, wrists, ankles, distal inter-phalangal joints
• MCP less commonly affects (unlike rheumatoid)

Question 7

Describe asymmetrical oligoarthritis

Answer 7

• ≤ 4 joints affected
• Typically affects the hands and feet

Question 8

Describe spondyloarthritis

Answer 8

Primarily affects the spine and sacroiliac joints

Question 9

Descibe distal arthritis

Answer 9

• Affects distal interphalangeal joints of hands and/or feet
• Usually occurs alongside other types

Question 10

Describe arthritis mutilans

Answer 10

• Most severe and least common form
• Deforming and destructive subtype
• Telescoping and flail digits (due to osteolysis of bone around joint)

Question 11

General symptoms seen in an inflammatory arthropathy

Answer 11

Joint pain and stiffness that is worse in the morning and improves on movement.

Question 12

Signs of psoriatic arthritis

Answer 12

• 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

Question 13

What is oncholysis?

Answer 13

Seperation of the nail from the nail bed

Question 14

What is dactylitis?

Answer 14

Swelling of the entire finger or toe

Question 15

What is enthesitis?

Answer 15

Inflammation of the entheses, which are the points of insertion of tendons into bone.

Question 16

Other associations with psoriatic arthritis

Answer 16

• Eye disease (conjunctivitis and anterior uveitis)
• Aortitis (inflammation of the aorta)
• Amyloidosis

Question 17

Which criteria must be fulfilled to diagnose psoriatic arthritis?

Answer 17

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

Question 18

What X-ray changes are seen for psoriatic arthritis?

Answer 18

• 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

Question 19

Management of psoriatic arthritis

Answer 19

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