Psoriatic arthritis

Question 1

What is psoriatic arthritis?

Answer 1

Psoriatic arthritis is an inflammatory arthritis associated with psoriasis, ranging in severity from mild stiffness to complete joint destruction.

Question 2

What percentage of psoriasis patients develop psoriatic arthritis?

Answer 2

Psoriatic arthritis occurs in 10-20% of patients with psoriasis, usually within 10 years of developing the skin condition.

Question 3

Can psoriatic arthritis develop before the skin changes?

Answer 3

Yes, arthritis can occur before the skin changes in some cases.

Question 4

What group of conditions does psoriatic arthritis belong to?

Answer 4

Psoriatic arthritis is part of the seronegative spondyloarthropathy group.

Question 5

What are some extra-articular manifestations of psoriatic arthritis?

Answer 5

• Uveitis
• Inflammatory bowel disease

Question 6

What are the 5 recognized patterns of psoriatic arthritis?

Answer 6

• Asymmetrical oligoarthritis
• Symmetrical polyarthritis
• Distal interphalangeal predominant pattern
• Spondylitis
• Arthritis mutilans

Question 7

What is asymmetrical oligoarthritis in psoriatic arthritis?

Answer 7

Asymmetrical oligoarthritis affects 1-4 joints, often on only one side of the body.

Question 8

What is symmetrical polyarthritis in psoriatic arthritis?

Answer 8

Symmetrical polyarthritis presents similarly to rheumatoid arthritis, affecting more than four joints, such as the hands, wrists, and ankles.

Question 9

What is the distal interphalangeal predominant pattern in psoriatic arthritis?

Answer 9

This pattern primarily affects the distal interphalangeal (DIP) joints, although DIP joints can be affected in all types of psoriatic arthritis.

Question 10

What is spondylitis in psoriatic arthritis?

Answer 10

Spondylitis involves back stiffness and pain, affecting the axial skeleton (spine and sacroiliac joints).

Question 11

What is arthritis mutilans in psoriatic arthritis?

Answer 11

Arthritis mutilans is the most severe form, causing osteolysis (destruction of bones) around the joints, leading to progressive shortening of the digits and a ‘telescoping digit’ appearance.

Question 12

What joints does psoriatic arthritis tend to affect that differentiate it from rheumatoid arthritis?

Answer 12

Psoriatic arthritis tends to affect the distal interphalangeal (DIP) joints and the axial skeleton, whereas rheumatoid arthritis typically does not.

Question 13

What are some key signs of psoriatic arthritis?

Answer 13

• Plaques of psoriasis on the skin
• Nail pitting
• Onycholysis (nail separation)
• Dactylitis (inflammation of the whole finger)
• Enthesitis (inflammation of tendon insertion sites)

Question 14

What is the Psoriasis Epidemiological Screening Tool (PEST)?

Answer 14

The PEST is a tool used to screen for psoriatic arthritis in patients with psoriasis. It includes questions about joint pain, swelling, arthritis history, and nail pitting.

Question 15

What x-ray changes are characteristic of psoriatic arthritis?

Answer 15

• Periostitis
• Ankylosis
• Osteolysis
• Dactylitis (soft tissue swelling)

Question 16

What is the ‘pencil-in-cup’ appearance in x-rays?

Answer 16

It is a classic finding in psoriatic arthritis, where one bone erodes centrally, forming a cup-like appearance, while the adjacent bone becomes pointed like a pencil. It is associated with arthritis mutilans.

Question 17

How is psoriatic arthritis managed?

Answer 17

Treatment often involves coordination between dermatologists, rheumatologists, and other healthcare providers, using:
* NSAIDs
* Steroids
* DMARDs (methotrexate, leflunomide, sulfasalazine)
* Anti-TNF medications (etanercept, infliximab, adalimumab)
* Ustekinumab (monoclonal antibody targeting interleukin 12 and 23)