Narrowband ultraviolet B phototherapy for patients with refractory uraemic pruritus: a randomized controlled trial

Background Pruritus is very common in uraemic patients, but the treatment remains challenging. Studies regarding narrowband ultraviolet B (NB-UVB) phototherapy for uraemic pruritus are rare. Objectives To investigate whether or not NB-UVB phototherapy is an effective treatment for uraemic pruritus. Methods We conducted a single-blind, randomized, controlled trial for patients with refractory uraemic pruritus. The treatment group received NB-UVB phototherapy three times per week for 6 weeks. The dose of NB-UVB started from 210 mJ cm(-2) and was increased by 10% each time. The control group received time-matched exposures to long-wave UVA radiation. A visual analogue scale (VAS) score was evaluated weekly for pruritus intensity for 12 weeks. The characteristics of pruritus were also assessed by a questionnaire at baseline and after 6 weeks of phototherapy. Results Both the NB-UVB and control groups had significant and comparable improvement in the pruritus intensity VAS scores during the period of phototherapy and follow-up. Compared with the control group, the NB-UVB group showed a significant improvement in the involved body surface area affected by pruritus (P = 0.006), but not in sleep quality. More detailed regression and estimating analysis revealed that the patients in the NB-UVB group had lower pruritus intensity scores at week 6, week 10 and week 12. This may indicate a beneficial difference at certain time points, but the effect seems marginal. Conclusions NB-UVB phototherapy does not show a significant effect in reducing pruritus intensity compared with a control group for refractory uraemic pruritus. Further studies are warranted.