CASPAR criteria require established inflammatory articular disease (joint, spine, or entheseal) plus a total of ≥3 points from the features below. Current psoriasis scores 2 points. All other items score 1 point.

Feature	Summary definition	Points
Current psoriasis	Psoriatic skin or scalp disease present at assessment, judged by a rheumatologist or dermatologist.	2
Personal history of psoriasis	Past psoriasis when no current psoriasis is present.	1
Family history of psoriasis	Psoriasis in a first- or second-degree relative when the patient has no current or past psoriasis.	1
Psoriatic nail dystrophy	Typical nail changes such as onycholysis, pitting, or hyperkeratosis.	1
Negative rheumatoid factor	Rheumatoid factor below the local laboratory reference range by standard assay.	1
Dactylitis	Current or past swelling of an entire finger or toe recorded by a rheumatologist.	1
Juxta-articular new bone formation	Ill-defined ossification near joint margins on hand or foot radiographs, excluding osteophytes.	1

CASPAR score = sum of points (range 0–6). A score ≥3, in the presence of inflammatory articular disease, fulfils CASPAR classification for psoriatic arthritis.

CASPAR Criteria for Psoriatic Arthritis