Established inflammatory musculoskeletal disease (joint, spine, or entheseal) with 3 or more of the following†. | ||
---|---|---|
1. Psoriasis | (a) Current | Psoriatic skin or scalp disease present today as judged by a qualified health professional |
(b) History | A history of psoriasis that may be obtained from patient or qualified health professional | |
(c) Family history | A history of psoriasis in a first or second degree relative according to patient report | |
2. Nail changes | Typical psoriatic nail dystrophy including onycholysis, pitting, and hyperkeratosis observed on current physical examination | |
3. A negative test for RF | By any method except latex but preferably by ELISA or nephelometry, according to the local laboratory reference range | |
4. Dactylitis | (a) Current | Swelling of an entire digit |
(b) History | History of dactylitis recorded by a qualified health professional | |
5. Radiological evidence of juxtaarticular new bone formation | Ill-defined ossification near joint margins (but excluding osteophyte formation) on plain radiographs of hand and foot |
* The CASPAR criteria have specificity of 98.7% and sensitivity of 91.4%.
↵† Patient must accrue ≥ 3 points total: Only one of the 3 subcriteria in criterion 1 may be applied, with 2 points accrued with fulfillment of criterion 1a, and 1 point for fulfillment of either 1b or 1c. Only one of the 2 subcriteria in criterion 4 may be applied, with 1 point for either 4a or 4b. The remaining points may be scored using criteria 2, 3, and 5, each of which may be assigned a score of 1. CASPAR: ClASsification of Psoriatic ARthritis; RF: rheumatoid factor: PsA: psoriatic arthritis.