Evaluation and management of psoriatic arthritis: the role of biologic therapy

Clinicians often view psoriatic arthritis (PsA) as a rather minor arthritic disorder because many are unaware of the substantial damage, disability, and reduced quality of life that patients with this disease can suffer. Compared with better-studied arthritic conditions, such as rheumatoid arthritis (RA) with well-known consequences of disease progression, PsA does not elicit the same urgency to treat early and aggressively. This is largely owing to the lack of predictive epidemiologic data regarding disease progression in PsA. However, numerous studies indicate that PsA and RA are comparable in terms of overall severity of joint involvement and disability over equivalent disease duration. Many of the drugs traditionally used for PsA therapy are also used to treat RA, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, methotrexate (MTX), sulfasalazine, cyclosporine, etretinate, auranofin, intramuscular gold, and azathioprine. All of these drugs have significant risk of toxicity over long-term use, and all provide variable efficacy. This makes it difficult for clinicians to make sound risk-benefit assessments regarding treatment or nontreatment of PsA, because the risks of disease progression cannot be weighed against the risks of therapy. The newer biologic antirheumatic drugs appear to combine greater efficacy of treatment with significantly less toxicity by targeting specific mediators involved in the pathogenesis of PsA.