Psoriatic arthritis Flashcards
What is psoriatic arthritis?
Inflammatory arthritis associated with psoriasis
But psoriasis not always present
It is a seronegative spondyloarthropathy (along with reactive arthritis and AS)
How does psoriatic arthritis present?
Varies in severity from mild stiffening through to arthritis mutilans (complete destruction of joint)
Can affect many different joints:
- Hands (DIPs usually)
- Wrist
- Ankle
- Back
- Sacroiliac joint
- Etc…
Signs seen in psoriatic arthritis
Plaques of psoriasis on the skin
Pitting of the nails
Onycholysis (separation of the nail from the nail bed)
Dactylitis (inflammation of the full finger or toe)
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
How can you screen 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.
X-ray changes in psoriatic arthritis
Pencil-in-cup appearance - central erosions beside joints causing appearance of one bone being hollow and looking like a cup whilst the other is narrow and sits in the cup.
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
What is arthritis mutilans?
There is osteolysis of the bones in the digits
Leads to progressive shortening of the digit and telescoping finger
Management of psoriatic arthritis
Similar to RA
NSAIDs for pain (or for mild disease)
DMARDS (methotrexate, leflunomide or sulfasalazine) - first line
Anti-TNF medications (etanercept, infliximab or adalimumab) are third line
Ustekinumab is last line (after anti-TNF medications) and is a monoclonal antibody that targets interleukin 12 and 23
