Psoriatic Arthritis

40 year old female, Hx of hand pain Findings & DDx?

Answers:

Psoriatic Arthritis:

* Images above showed bilateral, asymmetric joint destruction with soft tissue swelling and “pencil-in-cup” deformities, classic for Psoriatic Arthritis
* Main DDx is Reiter’s Syndrome, which can radiographically look identical, but would more likely involve the feet; note that the bony mineralization is normal, which makes Rheumatoid Arthritis less likely
* Psoriatic Arthritis, distinguishing features:
o Fusiform soft tissue swelling
o Maintenance of normal mineralization
o Dramatic joint space loss
o Bone proliferation (*key distinguishing feature from RA)
o pencil-in-cup” erosions
o Bilateral, asymmetrical distribution
o Distributed Hands > feet >SI joints > spine
Source: http://www.healthimaginghub.com/learning-center/radiology-teaching-files/2010/07/28/62-psoriatic-arthritis.html