Influence of placebo effects on quality of life and wound healing in patients with chronic venous leg ulcers

INTRODUCTION

Placebo effects are used in the treatment of various medical conditions. To date, there is little scientific data in this regard as it relates to skin diseases in general and hardly any data with respect to wound healing in particular.

MATERIAL AND METHODS

In a prospective randomized controlled trial, patients with chronic venous leg ulcers were observed for a period of 14 weeks. The objective was to investigate whether raising patients' expectations with regard to a novel wound treatment might have an effect on wound healing processes as well as wound-related quality of life, anxiety, depression and pain.

RESULTS

Overall, 20 patients were included in the trial. They were stratified based on gender and randomized to either the intervention (IG) or the control group (CG). In both groups, the wound area decreased significantly over the course of the observation period. Unlike patients in the CG, those in the IG experienced significant improvement in wound-related quality of life (wound-QoL) in terms of both the overall score and the various subscales. Neither group showed significant changes with respect to pain, anxiety and depression.

CONCLUSIONS

Our study is the first to show that - merely by raising patients' expectations for a novel treatment - placebo effects can significantly improve quality of life in patients with chronic venous leg ulcers. In the future, our findings should be integrated into the development of treatment concepts for patients with chronic wounds and should be investigated in larger cohorts.

What is new in the psychology of chronic itch?

Itch is often regarded as unpleasant or bothersome and is accompanied by symptoms of distress and impairments in daily life. The biopsychosocial model of chronic itch describes how psychological factors can contribute to the improvement or exacerbation of chronic itch and related scratching behaviour. Recent research underlines the important role of cognitive-affective information processing, such as attention, affect and expectancies. This may not only play a role for acute itch states, but may particularly apply to the process of itch chronification, for example, due to the vicious cycle in which these factors shape the experience of itch. The present paper focuses on new insights into the relation between itch and the cognitive-affective factors of attention, affect and expectancies. These factors are thought to play a possible aggravating role in itch in the long term and have received increasing attention in the recent empirical literature on maintaining and exacerbating factors for chronic physical symptoms. Possible psychophysiological and neurobiological pathways regarding these factors are discussed, as well as possible intervention methods.

Placebo and nocebo effects on itch: effects, mechanisms, and predictors

Placebo and nocebo effects have been extensively studied in the field of pain and more recently also on itch. In accordance with placebo research on pain, expectancy learning via verbal suggestion or conditioning has shown to induce placebo and nocebo effects on itch, in which the combination of both procedures seems most promising. Moreover, itch can also be transferred 'contagiously' in which suggestion and social behavioural learning seem to play a role. With regard to predictors of placebo and nocebo responding on itch and contagious itch, preliminary evidence suggests a role for individual psychological characteristics and personality traits regarding negative outcome expectancies. Although findings on placebo and nocebo effects on itch seem comparable to pain, we have only just begun to understand the underlying mechanisms and predictors of placebo and nocebo effects on itch.