Current concepts and new developments in the treatment of psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy characterized by the association of arthritis with psoriasis. Many agents have been proposed for the treatment of PsA, but their use is based more on clinical experience than on sound scientific evidence.

We reviewed MedLine up to November 2002, searching for 'psoriatic arthritis', 'drug therapy, 'controlled trials' and 'outcomes' and all possible acronyms for these terms. All relevant papers were then examined in detail.

PsA is a condition that runs a variable clinical course. Mild forms can usually be controlled by non-steroidal anti-inflammatory drugs (NSAIDs). Intra-articular glucocorticoid injections are indicated in patients with persistent mono- or oligoarthritis. Patients with severe and progressive articular disease not responsive to NSAIDs should be treated with disease-modifying anti-rheumatic drugs (DMARDs) to prevent joint damage and disability. Currently, methotrexate and sulphasalazine are considered the DMARDs of choice, but the evidence for the use of methotrexate in PsA is still largely empirical, while the clinical benefit induced by sulphasalazine appears to be modest. Other DMARDs proposed for the treatment of PsA include cyclosporin, gold salts and, more recently, leflunomide. However, none of the DMARDs available to date are effective in the treatment of psoriatic pelvispondylitis; in addition, a number of patients with severe peripheral arthritis fail to respond to standard DMARDs. Recently, tumour necrosis factor alpha inhibitors have proved effective in many PsA patients with pelvispondylitis or recalcitrant peripheral synovitis.

None of the current treatments for PsA is curative, but significant clinical amelioration can be achieved in the vast majority of patients. Identification and prompt treatment of patients with severe articular disease is crucial for the achievement of a satisfactory clinical response and the improvement of the long-term outcome.