Most knowledge about itch is derived from pain studies which leads to a lack of research on itch, especially on gender differences in itch. This study therefore investigated the mediation effect of...Show moreMost knowledge about itch is derived from pain studies which leads to a lack of research on itch, especially on gender differences in itch. This study therefore investigated the mediation effect of itch catastrophizing on gender and itch avoidance behaviour, in the context of a nocebo study. The participants’ itch catastrophizing levels were measured using self-reports and cowage spicules were used to induce itch in 11 healthy participants. Classical conditioning and verbal suggestion were used to induce nocebo effects. The expectancy acquisition phase comprised of conditioning the participants to believe that Cyclosol cream (the nocebo cream) evokes itch. The nocebo conditioning phase was followed by an avoidance acquisition phase where gripping strength was linked to a decrease in itch sensation, which served as a measure for avoidance behavior in the avoidance test phase. No nocebo effect or mediation effects were detected. Future research should expand on the influence of gender in the context of itch by expanding the sample size and by striving for a balanced gender distribution, especially by focusing on a clinical sample outside of a laboratory settingShow less
Itch is one of the most common conditions worldwide and can lead to higher anxiety and depression symptoms. There is ambiguity on whether anxiety and depression also affect it. This study...Show moreItch is one of the most common conditions worldwide and can lead to higher anxiety and depression symptoms. There is ambiguity on whether anxiety and depression also affect it. This study investigated whether gender affects itch ratings and if this is mediated by anxiety and/or depression. 11 healthy controls, 18 to 35 years old, participated in this study, whereby the DASS-21 and an additional four questionnaires were implemented to investigate the associations between the variables. A dynamometer measured itch avoidance and itch was evoked through cowhage spicules. Nocebo and verbal suggestions were also part of this study. Males scored higher on depression (M = 5, SD = 4.24), while females scored higher on anxiety (M = 6.67, SD = 5.74). The mediation analysis yielded no significant results, except for the indirect effect of depression and itch ratings at baseline, t(9) = 3.313, p = .011, and partial mediation: t(9) = 2.519, p = .036. The control condition of the expectation phase yielded a significant result regarding depression, t(9) = 3.453, p = .009. Overall, there were no significant relationships found between gender, anxiety, depression, and itch ratings, contradicting to previous literature. Due to the current small sample size, further research is needed to investigate the relationship between gender, psychological traits and itch ratings to improve treatment in clinical settings. This could be achieved through larger and more demographically varied samples.Show less
Background: Itch and scratching are distressing symptoms in diverse diseases. Both negative expectancies and stress have been shown to increase symptom severity. However, especially the role of...Show moreBackground: Itch and scratching are distressing symptoms in diverse diseases. Both negative expectancies and stress have been shown to increase symptom severity. However, especially the role of stress remains unclear as it has mostly been tested in pain studies. Methods: To investigate whether the effect of stress on itch is mediated by negative expectancies; cowhage, verbal suggestions and a video fragment were used to induce itch in a within-subjects design of 11 healthy participants. Itch, scratching and negative expectancies were measured on a scale from 0 to 10. Stress was assessed by the DASS-21 questionnaire. Results: Using mediation analysis, results suggested that stress was not predictive of itch symptoms at all, even when taking into account negative expectancies. Nonetheless, negative expectancies on their own were related to itch and scratching. Conclusions: These findings demonstrate that negative expectancies should be treated as a key aspect in psychological treatment targeting chronic pruritus, such as rational-emotive therapy (RET). However, future research should still investigate stress in relation to itch, as the current study did not assess the impact of severe stress levels and experimentally-induced stress.Show less
The theoretical framework of this research was based predominantly on the itch-anxiety cycle and the role of the HPA axis. This study aimed to explore the role of anxiety and depression as...Show moreThe theoretical framework of this research was based predominantly on the itch-anxiety cycle and the role of the HPA axis. This study aimed to explore the role of anxiety and depression as mediators in the relationship between mindfulness and nocebo effects in induced itch on healthy controls. Itch was induced using cowhage spicules, and mindfulness, anxiety and depression were measured using questionnaires which were administered before the experiment. The nocebo effect was calculated using itch ratings which were taken throughout the experiment. This study found that there was no significant association between any of the variables. Previously, mindfulness has been found to reduce anxiety and depression as well as itch. Limitations of this study included a high non-responsiveness to the itch stimuli as well as a low number of participants. Future research should explore how nocebo effects may influence potential treatments of chronic itch and how mediating psychological factors play a role in patients suffering from chronic itch.Show less
While itch and pain share several similarities in their working mechanisms and treatments, the role of mindfulness and catastrophising in the context of itch specifically has received limited...Show moreWhile itch and pain share several similarities in their working mechanisms and treatments, the role of mindfulness and catastrophising in the context of itch specifically has received limited attention in research. This study aimed to bridge this gap in the literature by investigating this relationship in healthy controls, using cowhage to induce itch across baseline, nocebo, and control conditions. The results revealed that mindfulness did not predict a reduction in itch ratings, and itch catastrophising did not mediate this relationship. Furthermore, no significant relationship between mindfulness, itch catastrophising, and itch ratings was found. These findings suggest the presence of underlying differences in pain and itch sensations, highlighting the need for further research on the role of the perceived threat value and neuroendocrine responses to itching stimuli. By better understanding the role of these factors, the development of more effective interventions to alleviate itch in acute and chronic patients can be developed.Show less
