PSORIASIS INTERNATIONAL
Consensus & controversies
Consensus & controversies
7. PSORIATIC ARTHRITIS
7. 4. Treatment
Treatment of psoriatic rheumatism can only be undertaken if the diagnosis is certain. This presupposes close collaboration between dermatologist and rheumatologist. The therapeutic strategy shall also be chosen jointly, in order to find the therapeutic solution that best improves the subject’s quality of life taking into account his/her skin and joints.
The treatments available are as follows:
- analgesics and non-steroidal anti-inflammatories;
- infiltrations into joints and synoviorthesis;
- general corticotherapy in small doses, 10 mg or less than 10 mg a day, as basic treatment. Dermatologists prefer to avoid this treatment in fear of exacerbating cutaneous psoriasis, but there is no evidence to support such fears;“ Does not agree. We prefer Mtx to steroids and salazopyrin.Olle Larkö
- Salazopyrin is used at a dose of 2 g a day. It calls for G6PD activity dosage prior to treatment. Above all, it is used to treat peripheral arthritis. Supervision involves a complete blood count and transaminases dosage every month;
- methotrexate is the core treatment of psoriatic arthritis. It is used in cases where Salazopyrin has failed or immediately if progressive psoriatic rheumatism is involved;
- orally administered retinoids (etretinate and acitretin) have some degree of efficacy in psoriatic arthritis. However, this efficacy has never been precisely assessed and it is only registered in doses close to 1 mg per kilo per day, hence with side effects that often make treatment intolerable.
- in the event of difficulties, two new therapeutic options are now available:
- Leflunomide, which inhibits T lymphocyte activation fairly selectively. This drug is given at a dose of 100 mg for three consecutive days. This “attack dose” is followed by maintenance treatment at a dose of 10 or 20 mg a day. Arterial pressure is monitored monthly, as are complete blood count, platelets and transaminases. Diarrhoea is sometimes observed at the start of treatment.
- TNF-alpha inhibitors (etanercept, adalimumab and infliximab). The former is administered subcutaneously at a dose of 25 mg twice a week. The second is administered subcutaneously at a starting dose of 80 mg and thereafter at 40mg every other week. The third is administered intravenously as a slow perfusion at a dose of 5 mg per kilo. This treatment is repeated after two weeks, then four weeks later, then every three months. It is usually combined with small doses of methotrexate once a week. The TNF-alpha inhibitors can reactivate old tuberculosis or chronic infections. They seem to be capable of contributing to the appearance of autoimmunity. They are contraindicated in cases of cardiac insufficiency and their use is avoided in patients suffering from cancer or multiple sclerosis.
“ Which patients deserve the more expensive new anti-TNF-α drugs etanercept, infliximab, and adalimumab, which gained FDA approval for the treatment of psoriatic arthritis in October, 2005 in the USA versus standard Methotrexate?? These drugs are expensive and yet show dramatic responses in both skin and joint disease, with joint manifestations frequently completely ameliorated within weeks of initiation on anti-TNF-α therapy. Question: Why do joints respond quicker than skin, even with maximum dosages of these drugs? Is it because there’s more TNF-α in the skin than in the joints, or is there a differential in the cellular infiltrate in skin and joints making joints more susceptible to therapy?
Alan Menter