There are no X-ray findings associated with psoriasis, though an X-ray can be used to diagnose psoriatic arthritis, which may lead to bone erosion and characteristic “pencil-in-cup” deformities. Psoriatic arthritis may also lead to periostitis, dactylitis, or arthritis mutilans.

There are no X-ray findings associated with psoriasis, though an X-ray can be used to diagnose psoriatic arthritis, which may lead to bone erosion and characteristic “pencil-in-cup” deformities.

• Key X-ray findings in cases of psoriatic arthritis include:^[1][2][3]
  • Enthesitis and marginal bone erosions
  • “Pencil-in-cup” deformities
  • Interphalangeal ankylosis may be found
  • Bone proliferation leads to inflammatory bone spur formation around the affected joints
  • Periostitis: Appears as a periosteal layer of new bone, or as irregular thickening of the cortex itself
  • Dactylitis: Which can present as a “sausage digit” which refers to soft tissue swelling of a whole digit
  • Arthritis mutilans: It may lead to “telescoping of fingers” caused by marked bony resorption and the subsequent collapse of soft tissue
  • Asymmetrical sacroiliitis
  • Spondylitis: Asymmetric paravertebral ossifications and relative sparing of the facet joints