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CASPAR criteria for psoriatic arthritis
Classifies established inflammatory arthritis as psoriatic arthritis.
CASPAR criteria for psoriatic arthritis
Established inflammatory articular disease (joint, spine, or entheseal)
CASPAR is a classification tool applied only once inflammatory articular disease is present - it is a prerequisite, not a scored item, and does not itself add points.
Psoriasis history
Only the highest-ranking category present is scored: current psoriasis outranks personal history, which outranks family history.
Psoriatic nail dystrophy (onycholysis, pitting, or hyperkeratosis) on current examination
Rheumatoid factor negative
By any method except latex, preferably ELISA or nephelometry.
Dactylitis - current (a whole swollen digit), or a history of dactylitis recorded by a rheumatologist
Juxta-articular new bone formation on a plain radiograph of the hand or foot (excluding osteophytes)
ResultNot applicable
CASPAR requires established inflammatory articular disease (joint, spine, or entheseal) as a prerequisite - without it, the criteria cannot classify the patient as psoriatic arthritis regardless of point count.
When to use
- Classifying a patient who already has confirmed inflammatory articular disease as having psoriatic arthritis, chiefly for research/cohort inclusion.
- Not intended as a screening tool for undiagnosed joint symptoms, and not a substitute for clinical diagnosis in an individual patient.
Formula
Requires established inflammatory articular disease plus ≥ 3 points from: current psoriasis (2 points) or personal/family history of psoriasis (1 point, only counted if current psoriasis is absent, and family history only if personal history is also absent); nail dystrophy (1); dactylitis, current or past (1); juxta-articular new bone formation on radiograph (1); negative rheumatoid factor (1).
Pearls and pitfalls
- More specific but less sensitive than the older Vasey and Espinoza or McGonagle criteria it was compared against.
- Developed from 588 PsA cases and 536 controls with other inflammatory arthropathies across multiple international rheumatology clinics.