The Numerical Rating Scale (NRS) is a validated tool for quantifying patient-reported pruritus, designed to measure peak pruritus, or ‘worst’ itch, over the previous 24 hrs, based on the following question:
On a scale of 0 to 10, with 0 being “no itch” and 10 being “worst itch imaginable”, how would you rate your itch at the worst moment during the previous 24 hours?