Randomized Double-blind Trial of the Treatment of Chronic Plaque Psoriasis

Abstract

To compare the efficacy of oral psoralen-UV-A (PUVA) therapy with that of narrowband UV-B (NB-UVB) therapy in patients with chronic plaque psoriasis. Double-blind randomized study. Phototherapy unit in a university hospital. Patients Ninety-three patients with chronic plaque psoriasis. Interventions Twice-weekly NB-UVB or PUVA therapy, starting at 70% of the minimum phototoxic or erythema dose, with 20% incremental increases. Patients were treated until clearance, up to a maximum of 30 sessions; those with clearance were followed up until relapse or for 12 months. Proportion of patients achieving clearance, number of treatments to clearance, and, among those with clearance, the proportion remaining in remission at 6 months. Patients with skin types V and VI had a lower rate of clearance than those with skin types I through IV (24% vs 75%; P = .001). In patients with skin types I through IV, PUVA was significantly more effective than NB-UVB at achieving clearance (84% vs 65%; P = .02). The median number of treatments to clearance was significantly lower in the PUVA group (17.0 vs 28.5; P<.001). More patients treated with PUVA vs NB-UVB were reported to have erythema at some stage during treatment (49% vs 22%; P = .004), although this difference may have been due to ascertainment bias. Six months after the cessation of therapy, 68% of PUVA-treated patients were still in remission vs 35% of NB-UVB-treated patients. Conclusion Compared with NB-UVB, PUVA achieves clearance in more patients with fewer treatment sessions and results in longer remissions.