Effects of ultra‐pure soft water on the hands of nurses in a neonatal intensive care unit: A randomized crossover study

Background Healthcare workers (HCWs) wash their hands with tap water (TW) and soap. However, hard TW causes dermatitis. Objectives The present study aimed to compare the effects of ultra‐pure soft water (UPSW) with those of TW on the hands of HWCs. Methods The present study was a prospective randomized trial with a crossover design. All the nurses in the neonatal intensive care unit (NICU) at the study centre were divided into Sequence 1 (UPSW to TW) or 2 (TW to UPSW) and washed their hands with TW or UPSW in alternating 4‐week periods with a 4‐week washout period. Trans‐epidermal water loss (TEWL) and stratum corneum hydration (SCH) were evaluated. Skin condition was self‐assessed. Results Twenty‐one and 22 nurses were assigned to Sequence 1 and Sequence 2, respectively. USPW increased SCH to a significantly greater degree than TW (mean: 26.3 μS ± 12.3 SD; 95% confidence interval: 1.12–51.54; p = 0.041) although it did not affect TEWL. UPSW use significantly improved the subjects' skin condition, as reflected in an overall increase in the assessment scores. Conclusions UPSW improved SCH and the condition of hand skin. Prolonged USPW use may increase nurses' comfort during work and hand hygiene compliance. Stratum corneum hydration (SCH) in the hands of NICU nurses significantly increased after washing with ultra‐pure soft water (UPSW) compared to tap water (TW). Hand skin dryness improved 1 week after the start of UPSW use, though self‐assessment.