Biopsychosocial mechanisms of chronic itch in patients with skin diseases: a review.

Itch is a major feature of many skin diseases, which adversely affects patient's quality of life. Besides disease severity, psychophysiological factors have been proposed to influence the itch sensation. In this review the evidence for a biopsychosocial model of itch is described, focusing in particular on evidence for the effects of personality characteristics, external stressors, cognitive, behavioural and social factors, and the possible mediating role of physiological processes. Research so far indicates that stressors may have a role in the itch sensation of patients with skin diseases. Furthermore, cognitive factors, such as helplessness and worrying, and the behavioural response of scratching have been indicated as possible worsening factors. Overall, findings are in favour of a biopsychosocial model for the itch sensation. However, there is a strong need for more, methodologically sound research in order fully to understand the processes underlying the itch sensation.