Efficacy of a fermented rice extract bath preparation on pruritus in patients undergoing hemodialysis: A single-center, randomized, open-label, crossover study

Chronic kidney disease-associated pruritus is common in hemodialysis patients and is linked to various complications. This study evaluates the efficacy of a bath preparation containing fermented rice extract in alleviating pruritus. This single-center, randomized, open-label crossover study involved 13 hemodialysis patients with pruritus. Four patients discontinued during the study due to a change in treatment, hospitalization, COVID-19 infection, and fragrance aversion. Nine patients completed the study. Patients underwent a 28-day phase with a fermented rice extract bath preparation or control, followed by a 28-day washout and crossover. Patients added fermented rice extract to their baths during the preparation phase and avoided towel rubbing. Participants did not use rice extract in the control phase and were allowed to rub their bodies. The primary endpoint was a change in the visual analog scale (VAS) score for pruritus from baseline (days 0–days 28). The secondary endpoints were Shiratori severity scores for daytime and night-time pruritus, pruritus frequency criteria, and skin moisture content of the inner forearm. The VAS score change was significantly lower in the rice extract phase than in the control phase (-20 (-45−-12) vs. 14 (-1−15), P = 0.009). The Shiratori severity scores were significantly reduced in the rice extract phase (daytime, P = 0.021; night-time, P = 0.032). More patients in the rice extract phase had less frequent pruritus (66.7 % vs. 0 %, P = 0.009). No patients experienced adverse events. Although this was a small, single-center study, bath preparations containing fermented rice extract appeared to alleviate pruritus in patients undergoing hemodialysis without safety concerns. These preliminary findings warrant further investigation in larger, multicenter, placebo-controlled trials to confirm efficacy, evaluate long-term safety, and elucidate the underlying mechanisms of action.