Randomized double-blind trial of the treatment of chronic plaque psoriasis: efficacy of psoralen-UV-A therapy vs narrowband UV-B therapy

Abstract

Objective: 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.

Design: Double-blind randomized study.

Setting: 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.

Main outcome measures: Proportion of patients achieving clearance, number of treatments to clearance, and, among those with clearance, the proportion remaining in remission at 6 months.

Results: 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.