Psoriatic arthritis as a distinct disease entity.

Psoriatic arthritis (PsA) is a chronic systemic inflammatory disease characterized by joint inflammation associated with cutaneous psoriasis. For many years, the amount of attention directed to PsA had been less than that for various other arthropathies. With the advances in understanding its pathogensis, it is now recognized as a distinct disease entity with characteristic features. Psoriatic arthritis has a greater tendency towards asymmetric oligoarticular involvement, distal interphalangeal involvement and spondylitis. Associated features such as enthesitis and dactylitis are more common. Specific radiological features include ankylosis and bone resorption. With the availability of potent new therapeutic agents for psoriasis and PsA, interest in research and clinical care for these conditions has been reinvigorated. Anti-TNF therapy has achieved encouraging efficacy in both the joints and skin disease, improving function and quality of life and inhibiting radiological progression measured in patients with PsA and psoriasis. Biologic agents may have the potential in addressing the unmet medical need in patients with PsA.