There are no definitive Laboratory tests for psoriatic arthritis.
- Elevated ESR and CRP
- anti-CCP antibodies
- Uric acid level may be elevated
- HLA-B27 (mostly found in the Axial Pattern of Disease)
- pencil-in-cup appearance in x-ray
- whiskering
- telescoping digits
- asymmetric sacroiliitis
The Caspar (Classification Criteria for Psoriatic Arthritis) Criteria
a patient must have inflammatory articular disease (joint, spine, or entheseal) with 3 points from any of the following:
- Evidence of current psoriasis (2 points), a personal history of psoriasis (1 point), or a family history of psoriasis (1 point)
- psoriatic nail dystrophy on current physical examination (1 point)
- A negative RF(1 point)
- Current dactylitis or history of dactylitis recorded by a rheumatologist(1 point)
- Radiographic evidence of juxtaarticular new bone formation in the hand or foot(1 point)