Psoriatic Arthritis Criteria

• psoriatic changes in the skin?

• psoriatic changes in nails?

• pain and soft tissue swelling in distal interphalangeal joints for more than 4 weeks?

• pain and soft tissue swelling of peripheral joints in an asymmetrical pattern for > 4 weeks (includes 'sausage digit')?

• symmetrical peripheral arthritis for more than 4 weeks?

• rheumatoid factor or subcutaneous (rheumatoid) nodules?

• radiographic changes in peripheral joints ('pencil in cup' deformity; 'whittling' of terminal phalanges, 'fluffy periostitis', 'bony ankylosis')?

• spinal pain, stiffness and restriction motion for more than 4 weeks?

• radiologic evidence of sacroiliitis (New York Grade II symmetrical sacroiliitis' Grade III or IV unilateral sacroiliitis)?