Water and light bath plus UV treatment proves successful in treating psoriasis

February 1, 2008

Physicians can sometimes be oerwhelmed by the many treatment modalities for psoriasis, including the many nuances of phototherapy. The results of a recent study define which phototherapy treatment works best in patients with moderate to severe psoriasis.

Key Points

Ulm, Germany - As the armamentarium of psoriasis treatments consistently grows, physicians seem to be armed to the teeth with a plethora of therapeutic options for their patients, including topical treatments, systemic treatments, biologics and phototherapy.

Though phototherapy is a leading treatment of psoriasis, several different types of treatment can be employed. A recent study investigates the types of phototherapy, pointing to which works best for psoriasis.

"Psoriasis can sometimes be very challenging to treat effectively, especially the more severe forms. Though we have several systemic therapies at our disposal, these are often not well-tolerated by the patient, and their long-term safety is not proven yet.

Dr. Schiener discusses the results of a multi-site, unblinded, randomized clinical trial in patients with stable, moderate to severe psoriasis, in which the efficacy of psoralens dissolved in a warm water bath followed by exposure to UVA irradiation or saltwater phototherapy with UVB was compared to tap water UVB therapy or UVB irradiation alone.

Study details

The study consisted of 1,241 patients from 102 dermatologic outpatient clinics, with moderate to severe psoriasis symptoms, all of the patients having a PASI of 7 or greater.

Study participants were randomized to receive either UVB, tap water UVB, saltwater UVB, or bath PUVA with baths preceding ultraviolet irradiation, four times a week, for a maximum of eight weeks.

Results showed that both bath psoralen UVA and saltwater UVB are distinctly more effective than tap water UVB, and that tap water UVB is more effective than UVB therapy alone.

The patients who received tap water UVB showed a significantly higher therapeutic success than those who received UVB alone (60.7 percent versus 43.3 percent).

However, the patients who received saltwater UVB or bath PUVA did significantly better than those patients who were treated with tap water UVB (74.9 percent versus 60.7 percent and 78.4 percent versus 60.7 percent).

Bath water PUVA and saltwater UVB therapies proved to be comparably effective (78.4 percent versus 74.9 percent).

Dr. Schiener says at baseline, the patients in the study had a median PASI of 17, and psoriatic patients with such severe disease can easily be considered for systemic therapies.

However, compared with saltwater UVB or bath PUVA, systemic therapies are fraught with complications and adverse events such as hepatotoxicity, nephrotoxicity, hypertension, immunosuppression, gastrointestinal adverse effects and teratogenicity.

"By delivering the psoralens through the bath, we are able to circumvent any systemic adverse events associated with the oral administration of psoralens.

"In my opinion, bath PUVA is the better therapeutic avenue to take because of its selective and shorter photosensitization, which is extremely helpful in lowering the cumulative UVA exposure to the patient.

"Furthermore, the therapeutic benefit of saltwater UVB or bath PUVA - after eight weeks in our study - seems to be comparable to the results obtained by Heydendael et al for methotrexate and cyclosporine, just two examples of the heavier systemic medications available," Dr. Schiener tells Dermatology Times.

"Further research should be directed to large-scale observational trials to assess the safety of repeated courses of UV treatment, as well as the benefit, risks and costs of systemic anti-psoriatics compared with saltwater UVB and bath PUVA in the long term," Dr. Schiener says.