Itch Severity and Quality of Life in Patients with Pruritus: Preliminary Validity of a Danish Adaptation of the Itch Severity Scale

The aim of this study was to examine the validity of a Danish adaptation of the Itch Severity Scale (ISS) by exploring the associations between pruritus severity, psychological symptoms, and quality of life in a consecutively recruited sample of 20 patients with atopic dermatitis, 20 with psoriasis, 20 with urticaria, 12 with genital pruritus, 11 with nephrogenic pruritus, and 20 controls with vascular malformations. Convergent and discriminative validity was explored by analysing the associations of the ISS total score and the individual ISS component scores with age, sex, diagnosis, disease severity, sleep quality, depressive symptoms, anxiety, non-specific somatic symptoms, and pruritus-related quality of life impairment. Patients with urticaria reported significantly (p<0.05) greater pruritus severity scores than the remaining patient groups, and pruritus severity was significantly associated with impaired sleep quality, more depressive symptoms, higher levels of anxiety, more non-specific somatic symptoms, and impaired quality of life. The results also confirmed the multidimensional nature of pruritus, with the affective dimension of pruritus being a better predictor of depressive symptoms, anxiety, and quality of life impairment than the sensory dimension. Finally, our results confirmed previous findings that the associations between pruritus severity and depressive symptoms and somatic symptoms were partly mediated by the effect of pruritus on sleep quality.