Bath psoralen+ultraviolet A photochemotherapy vs. narrow band-ultraviolet B in psoriasis: a comparison of clinical outcome and effect on circulating T-helper and T-suppressor/cytotoxic cells

Background: Comparative success rates of bath psoralen+ultraviolet A (PUVA) and narrow band-ultraviolet B (NB-UVB) in psoriasis treatment are variably reported with no previous studies on the possible effect of bath PUVA on circulating CD4+ and CD8+ T cells. Objective: We aimed to compare the effect of bath PUVA and NB-UVB clinically and on circulating T-helper and T-suppressor/cytotoxic cells in psoriasis. Patients and methods: Thirty-four psoriatic patients divided into a bath PUVA-treated group (18 patients) and a NB-UVB-treated group (16 patients) were compared regarding the disease severity by psoriasis area and severity index (PASI) score and percentage of circulating CD4+ and CD8+ T cells by flowcytometry before and after treatment. Results: After treatment, the bath PUVA group showed a significantly higher reduction of PASI score (85.44%) than the NB-UVB group (58.72%). Mean peripheral CD4+ T-cell percentage was significantly lower after [36.8; 95% confidence interval (CI) 33.80, 39.97] compared with before treatment (42.06; 95% CI 38.29, 45.83) (P < 0.05) in the bath PUVA group while this difference was insignificant in the NB-UVB group (P > 0.05). Conclusion: Bath PUVA therapy is superior to NB-UVB in the treatment of moderate and severe psoriasis with mild reversible side effects. Both modalities have a systemic effect decreasing peripheral CD4+ T cells, which is more with bath PUVA.