CASPAR Criteria for Psoriatic Arthritis

CASPAR criteria for psoriatic arthritis: applied after established inflammatory articular disease, >=3 of the 6 points classifies (Taylor 2006).

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Entry condition
Yes
Psoriasis
Current psoriasis (2)
Psoriatic nail dystrophy (onycholysis, pitting, hyperkeratosis)
Yes

Result: CASPAR 3/6 — inflammatory articular disease and ≥ 3 points: classify as psoriatic arthritis.

The tool opens with these values already filled in. Replace them with your own.

What the result means

Threshold
entry condition AND ≥ 3 points classifies as psoriatic arthritis (sensitivity 0.91, specificity 0.99). Current psoriasis is the only 2-point item.

What you enter

  • Entry condition (established inflammatory articular disease: joint, spine, or entheseal)
  • Psoriasis (highest applies)
  • Psoriatic nail dystrophy (onycholysis, pitting, hyperkeratosis) (+1)
  • Negative rheumatoid factor (any method except latex) (+1)
  • Dactylitis (current or recorded history) (+1)
  • Juxta-articular new bone formation on hand / foot radiograph (+1)
How this is calculated
Items
after the inflammatory-articular-disease entry: psoriasis (current 2 / personal or family history 1), nail dystrophy 1, negative RF 1, dactylitis 1, juxta-articular new bone 1, max 6.

Taylor W, Gladman D, Helliwell P, et al. Classification criteria for psoriatic arthritis: development of new criteria from a large international study. Arthritis Rheum. 2006;54(8):2665-2670. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.