Dynamic Pruritus Score: Evaluation of the Validity and Reliability of a New Instrument to Assess the Course of Pruritus.

Currently valid itch intensity scales, such as the visual analogue scale (VAS), are indispensable, but they can be influenced by the patient's overall health status. The aim of this study was to evaluate the reliability and validity of the Dynamic Pruritus Score (DPS), a new instrument comparing reduction in current pruritus with a defined earlier time-point. Eighty-one randomly selected adults (50 females, mean age 53.9 years) recorded their pruritus at visit 1 and repeatedly at visit 2 on the DPS, VAS, numerical rating scale, and on health status questionnaires (EuroQol; EQ-5D), skin-related quality of life (Dermatology Life Quality Index; DLQI), anxiety and depression (Hospital Anxiety and Depression Scale; HADS) and patient benefit (Patient Benefit Index; PBI). Intraclass correlation showed high reliability for both DPS and VAS (r < 0.9, p < 0.001), while the DPS has shown higher concurrent validity (rDPS to PBI = 0.570; p < 0.001). The DPS can then be considered an alternative instrument to the VAS for assessment of pruritus in adults. Further research is needed to confirm these results with a more representative sample size.