PSORIATIC ARTHRITIS

Question 1

What is PA?

Answer 1

• a chronic inflammatory joint disease which develops in patients with psoriasis
• It is a spondyloarthropathy.
• characteristically RF negative.

Question 2

What are the 5 pattern types of PA?

Answer 2

• Symmetrical seronegative polyarthritis (Rheumatoid-like polyarthritis)-30-40% so most common type
• Asymmetrical oligoarthritis: typically affects hands and feet (20-30%)
• Sacroilitis
• DIP joint disease (10%):
• Arthritis mutilans (severe deformity fingers/hand, ‘telescoping fingers’)-5%

Question 3

Describe DIP joint disease in PA

Answer 3

• MOST TYPICAL PATTERN of joint involvement in psoriasis
• Often with adjacent nail dystrophy, reflecting enthesitis extending into the nail root
• root
• Dactylitis (sausage fingers), in which an entire finger or toes is swollen

Question 4

Describe the pathophysiology of PA

Answer 4

• Occurs in some patients with psoriasis - arthritis can present before skin changes, after skin changes, or no skin changes. So can occur without psoriasis
• Typically involves joints of the axial skeleton with an asymmetrical pattern.
• Symmetrical Polyarthritis / Spine
• DIP joints mainly affected

Question 5

Where does psoriasis mainly occur?

Answer 5

-extensor surfaces such as the knees and elbows

Hidden sites for psoriasis:

• Behind ear/inside ear
• Scalp
• Pitting in nails or onokylisis
• Umbilicus, natal cleft and penile psoriasis

Question 6

Describe the presentation of PA

Answer 6

• Psoriatic Arthritis Mutilans - marked bony resorption and the consequent collapse of soft tissue, can cause a phenomenon sometimes referred to as “telescoping fingers”.
• Associated nail changes in 80% - Nail pitting and Onycholysis
• Psoriatic rash
• Dactylitis

Question 7

What investigations are done for RA?

Answer 7

• Bloods - RF negative and ESR is often normal

- X - ray

Question 8

What is seen on an X-ray for RA?

Answer 8

• DIPs are predominantly affected

- Pencil-in-cup’ changes are seen as the disease progresses (due to periarticular erosions and bone resorption)

Question 9

What is the treatment for RA?

Answer 9

Similar treatment to RA, but it has a better prognosis:

1. NSAIDs – 1st line for pain relief and soft tissue and inflammation
2. DMARDS e.g. Sulfasalazine, Methotrexate, Leflunomide – 1st line for those with progressive peripheral joint disease (usually Methotrexate) – combination of Methotrexate and ciclosporin is particularly effective. The Initial trial of DMARDs is done for 3 months
3. Intra articular steroid injections - for local synovitis
4. Anti-TNF e.g. Etanercept and Golimumab – highly effective for severe skin and joint disease. These are used when methotrexate has failed

*Caution with glucocorticoids: may cause flare in psoriasis