Table 1.
The classification for psoriatic arthritis criteria[7] for diagnosing psoriatic arthritis-related inflammatory musculoskeletal disease (joint, spine or entheseal)
| Evidence of psoriasis (any of three) |
| Current1: Psoriatic skin or scalp disease present, as judged by a dermatologist or rheumatologist (score of 2) |
| Personal history: May be obtained from the patient, family doctor, dermatologist, or rheumatologist (score of 1) |
| Family history: In a first- or second-degree relative, according to patient report (score of 1) |
| Psoriatic nail dystrophy |
| Typical psoriatic Nail dystrophy, including onycholysis, pitting, and hyperkeratosis, observed on current physical examination (score of 1) |
| Negative rheumatoid factor |
| By any method except latex, but preferably by enzyme-linked immunosorbent assay or nephelometry, according to the local laboratory reference range (score of 1) |
| Dactylitis |
| Current: swelling of an entire digit (score of 1) |
| Personal history: recorded by a rheumatologist (score of 1) |
| Radiological evidence of juxta-articular new bone formation |
| Ill-defined ossification near the joint margins (but excluding osteophyte formation) on plain X-rays of the hand or foot (score of 1) |
1
Current: Psoriasis score of 2; others: 1. A PsA patient must have inflammatory articular disease with > 3 points from the following 5 categories.