The most commonly used tool for self-report of pruritus intensity is the visual analogue scale (VAS). Similar tools are the numerical rating scale (NRS) and verbal rating scale (VRS). In the present study, initiated by the International Forum for the Study of Itch assessing reliability of these tools, 471 randomly selected patients with chronic itch (200 males, 271 females, mean age 58.44 years) recorded their pruritus intensity on VAS (100-mm line), NRS (0-10) and VRS (four-point) scales. Re-test reliability was analysed in a subgroup of 250 patients after one hour. Statistical analysis showed a high reliability and concurrent validity (r>0.8; p<0.01) for all tools. Mean values of all scales showed a high correlation. In conclusion, high reliability and concurrent validity was found for VAS, NRS and VRS. On re-test, higher correlation and less missing values were observed. A training session before starting a clinical trial is recommended.

The aim of this study was to evaluate the visual analogue scale (VAS) as a method of pruritus assessment. A total of 310 subjects with pruritic dermatoses (148 Caucasian subjects and 162 Asian subjects) were recruited. The patients assessed pruritus intensity using the horizontal and vertical VAS, numeric rating scale (NRS) and verbal rating scale (VRS). All scales showed very good reproducibility (intraclass coefficient (ICC) > 0.8). No significant differences were found between the horizontal and vertical VAS (5.3 ± 2.9 vs. 5.3 ± 3.0 points, p = 0.34). Using NRS, patients rated their pruritus significantly higher than with VAS (5.7 ± 2.6 points, p < 0.01). VRS showed the highest correlation with NRS (R = 0.82, p < 0.001), followed by horizontal (R = 0.75, p < 0.001) and vertical VAS (R=0.74, p < 0.001). Based on detailed analysis following VAS categories were proposed: 0 = no pruritus, > 0-< 4 points = mild pruritus, ≥ 4-< 7 points = moderate pruritus, ≥ 7-< 9 points = severe pruritus, and ≥ 9 points = very severe pruritus. In conclusion, the VAS is a valuable method of pruritus measurement.

PN does not seem to represent a characteristic symptom of one disease only. Multiple pruritogenic diseases are linked to evolution and improvement of PN upon treatment. Atopic predisposition is a major factor in nearly half of PN patients. The large collective of the present study helped detect a broad range of underlying diseases and thus to provide recommendations for rational diagnostics.

Chronic pruritus is a common symptom and there is an urgent need to test new anti-pruritic substances in high-quality clinical trials. However, no widely accepted standardized and validated method for objectively measuring pruritus is yet available. A special interest group of the International Forum for the Study of Itch has been established to assess scoring methods and questionnaires for use in clinical trials. This paper presents our current recommendations. The set of measures we recommend includes pruritus intensity scales, instruments for assessment of scratch lesions, chronic pruritus course, quality of life and patient benefits.

Background: Pruritus is a frequent symptom in many diseases; its prevalence in German adults is unknown. Objective: Our purpose was to assess the prevalence, severity and health care of chronic pruritus in the German working population. Methods: A cross-sectional observational study was conducted in employees of 144 German companies. Pruritus-specific data were obtained by standardized questions. Results: 11,730 people (53.2% male, 16–70 years, mean = 43.7 years) were suitable for analysis. The point prevalence of chronic pruritus (at least 6 weeks prior to data collection) was 16.8%. The prevalence increased with age from 12.3% (16–30 years) to 20.3% (61–70 years). A quarter of the affected persons had suffered from pruritus for >5 years, 47% had never sought medical advice, and 94% had not undergone any treatment. Conclusions: Chronic pruritus is a prevalent symptom in the working age population. A high proportion of people affected are not medically treated.