Psoriatic arthritis

Psoriatic arthritis (PsA) is a heterogeneous disease with multiple clinical manifestations including peripheral arthritis, spondyloarthritis, dactylitis, enthesitis, and skin and nail psoriasis.

PsA occurs in around 25% of patients with psoriasis. Arthritis may develop before skin symptoms.

Distinguished from rheumatoid arthritis by the pattern of joint involvement, and the presence of psoriatic disease-specific manifestations including dactylitis, enthesitis, nail psoriasis, and spondyloarthritis. Most people with PsA have seronegative arthritis.

Management involves the use of nonsteroidal anti-inflammatory drugs, conventional synthetic disease-modifying antirheumatic drugs (DMARDs), biologic agents, targeted DMARDs, and supportive measures, depending on clinical presentation and disease severity.

Psoriatic arthritis is a chronic inflammatory musculoskeletal disease associated with psoriasis. It manifests with seronegative inflammatory arthritis commonly presenting with skin and nail lesions, peripheral arthritis, dactylitis, enthesitis, and spondylitis. It can be differentiated from rheumatoid arthritis (RA) by several clinical features, including a frequent oligoarticular or monoarticular initial pattern of joint involvement as well as distal interphalangeal joint involvement. Dactylitis and sacroiliitis are not observed in RA. Over time many patients will progress to a polyarticular pattern of joint involvement with erosive and new bone-forming arthritis.