Presentation
Chronic pain to hands and fingers. Normal rheumatoid factor and serum uric acid levels.
Patient Data
Periarticular osteopenia and bony erosions predominantly in the phalanges and interphalangeal joints. Characteristic enthesopathy and pencil-in-cup deformity can be seen particularly in the right 4th proximal phalanx.
Further sclerosis and degenerative changes are noted between the scaphoid and trapezoid, and the scaphoid and trapezium.
Incidental note is made of bilateral capitohamate coalition.
Case Discussion
A case of psoriatic arthritis in a patient with a longstanding background of psoriasis.
Psoriatic arthritis is a seronegative spondyloarthropathy characterized by its association with psoriatic skin changes.
It predominantly affects the DIP joints with the hands being more commonly affected than the feet. While the appearance can be quite characteristic on imaging, it shares many similarities with other inflammatory arthritides and rheumatoid factor and uric acid should be checked to exclude rheumatoid arthritis and gout.