Pruritus Intensity Scales across Europe: a prospective validation study

Area of Science:

• Dermatology
• Clinical Assessment
• Patient-Reported Outcomes

Background:

• Chronic pruritus (CP) assessment requires validated patient-reported outcome tools.
• Existing itch intensity scales have limitations due to small cohorts and single-language validation.

Purpose of the Study:

• To validate numerical rating scale (NRS), verbal rating scale (VRS), and visual analogue scale (VAS) for worst and average pruritus intensity.
• To assess these scales across multiple European languages and diverse pruritic dermatoses.

Main Methods:

• Professional translation and digitization of scales into a tablet application.
• Validation conducted in dermatology clinics across Austria, France, Germany, Italy, Poland, Russia, Spain, Switzerland, and Turkey.
• Inclusion of 547 patients with conditions like contact dermatitis, chronic nodular prurigo, psoriasis, lichen planus, and cutaneous T-cell lymphoma.

Main Results:

• Scales demonstrated high reproducibility and inter-correlations.
• Correlation with Dermatology Life Quality Index varied from weak to strong across countries and dermatoses, with exceptions noted.
• Visual analogue scale for worst pruritus (VAS worst) showed excellent reproducibility and consistency.

Conclusions:

• NRS, VRS, and VAS are valid instruments for assessing pruritus intensity in German, French, Italian, Polish, Russian, Spanish, and Turkish.
• These scales exhibit good reproducibility and internal consistency for various pruritic dermatoses.
• VAS worst is identified as the most reproducible and consistent measurement tool across all evaluated countries.