What Is Psoriatic Arthritis

Definition

Psoriatic arthritis is an inflammatory arthritis associated with psoriasis.

The arthritis presents with pain, swelling and stiffness which is worse at rest and improves with activity.

Additional features include inflammation of the back and sacroiliac joints (spondylitis), inflammation at sites of tendon insertion into bone (enthesitis), inflammation of the whole digit (dactylitis).

Different clinical features

There are still no widely accepted classification or diagnostic criteria for PsA. Currently the descriptive patterns of Moll and Wright are used:

• Distal pattern - the end joints (distal) of the fingers and/or toes
• Oligoarticular pattern - 4 or less joints involved, often in an asymmetric distribution
• Polyarticular pattern - 5 or more joints involved may be symmetrical. This pattern looks like rheumatoid arthritis.
• Spondyloarthritis - involving the spine and sacroiliac joints
• Arthritis mutilans – a severe, deforming form of arthritis

In their original description Moll and Wright found that oligoarthritis occurred in 70% of the patients, polyarthritis in about 18% of the patients and distal arthritis and arthritis mutilans each in about 5% of the patients. Spondylitis alone occurred in about 2% of the patients but spondyloarthirtis occurred with peripheral arthritis in about 40% of the patients. It is now clear that over time patients change pattern and the majority of patients reported in studies demonstrate polyarthritis.

Disease impact

• The disease has an impact on the individual
• Aside from the actual pain, stiffness, and limitation of movement of the affected joints, patients with psoriatic arthritis also display reduced quality of life and functional disability, as measured by quality of life and functional instruments

Psoriatic Arthritis Basics   |   Top