Clinical validation and utility of Chinese Eppendorf Itch Questionnaire in adults with chronic pruritus symptoms

Background: Pruritus, or itch, is a prevalent symptom causing profound health burden in many dermatological and non-dermatological disorders. Several itch questionnaires have been created to assess itch. Particularly, Eppendorf Itch Questionnaire (EIQ) is widely accepted since it encompasses various aspects of itch, including intensity, affects, coping behavior, and motivation to scratch. Methods: In a cross-sectional survey, we examined the validity, reliability and clinical utility of Traditional Chinese EIQ. Results: We administered the consensus version to 128 adults (median: 48.5 years, interquartile range [IQR]: 39-63) with active itch for more than 6 weeks at the Outpatient Clinics of three medical centers in Taiwan. Clinical diagnoses included psoriasis (N = 82), xerosis (N = 34), or other dermatitis (N = 12). Cronbach's alpha for each EIQ scale ranged 0.82 - 0.98, suggesting good to excellent internal consistency and reliability. Three EIQ scales significantly correlated with visual analogue scale (VAS) for itch intensity (P <= 0.001 for median test), supporting for its concurrent validity. None of EIQ scale was statistically correlated with Psoriasis Area Severity Index (PASI) scores in psoriasis patients, confirming its discriminant validity. Moreover, patients of different diagnoses had distinct responses to the multi-scale EIQ index, affording it a better clinical test (area-under-the-ROC curve [AUC]: 0.76, 95% CI: 0.63 - 0.90) than VAS alone (AUC: 0.42, 95%CI: 0.24-0.59) in distinguishing dermatitis/eczemarelated itch from psoriasis or xerosis-related itch. Conclusion: We demonstrated the reliability and validity of Chinese EIQ in adult patients with chronic itch at the outpatient setting. The study also revealed the diversified aspects of itch across patients with various dermatoses. Copyright (C) 2020, Formosan Medical Association. Published by Elsevier Taiwan LLC.

Automated summary

The Chinese version of the Eppendorf Itch Questionnaire (EIQ) has been validated for use in adult patients with chronic itch in outpatient settings. The questionnaire demonstrated good reliability and validity, with patients showing different responses to itch across various dermatoses. The multi-scale EIQ index was found to be more effective in distinguishing eczema-related itch from psoriasis or xerosis-related itch than the visual analogue scale alone.