Purpose: The present study explored whether people with psoriasis display an attentional bias towards disease-related threat words and whether this bias occurs relatively early during the phase of stimulus disengagement, or during a later maintained attention phase dominated by controlled strategic processes. We also explored the degree to which attentional bias is dependent on the emotional valence of control words.
Methods: Individuals with psoriasis and matched controls took part in 4 online experiments.
Introduction: Itch is unpleasant and induces the urge to scratch. This is adaptive to remove the itch-inducing stimulus from the skin. Accordingly, itch draws attention to protect our bodily integrity.
View Article and Find Full Text PDFObjective: In past decades, the field of nocebo research has focused on studying how sensory perception can be shaped by learning. Nocebo effects refer to aggravated sensory experiences or increased sensitivity to sensations such as pain and itch resulting from treatment-related negative experiences. Behavioral conditioning and verbal suggestions of a negative treatment outcome may aggravate pain and itch perception.
View Article and Find Full Text PDFPlacebo effects, positive treatment outcomes that go beyond treatment processes, can alter sensations through learning mechanisms. Understanding how methodological factors contribute to the magnitude of placebo effects will help define the mechanisms by which these effects occur. We conducted a systematic review and meta-analysis of experimental placebo studies in cutaneous pain and itch in healthy samples, focused on how differences in methodology contribute to the resulting placebo effect magnitude.
View Article and Find Full Text PDFRapidly attending towards potentially harmful stimuli to prevent possible damage to the body is a critical component of adaptive behavior. Research suggests that individuals display an attentional bias, i.e.
View Article and Find Full Text PDFContagious itch can be evoked by observing people scratching. Verbal suggestions about to-be-received itch can influence itch intensity, as shown by placebo research, but it is unknown whether this extends to contagious itch. The current study aimed to replicate prior findings that listening to scratching and rubbing sounds elicits contagious itch, and to investigate whether suggestions can modulate this process.
View Article and Find Full Text PDFBackground: Nocebo and placebo effects, i.e., adverse or beneficial treatment effects, respectively, putatively due to expectancies can modulate pain and itch.
View Article and Find Full Text PDFAttention is known to modulate itch intensity. In contrast, the reverse relationship, i.e.
View Article and Find Full Text PDFA large proportion of patients with burn injuries develop chronic itch, which impacts quality of life. The underlying pathophysiological mechanisms are poorly understood. This cross-sectional pilot study investigates whether altered cortical oscillatory processes are involved in chronic post-burn itch.
View Article and Find Full Text PDFNocebo effects, that is, negative treatment outcomes due to negative expectancies, can increase itch. Moreover, indirect evidence has shown that nocebo hyperknesis can generalize to another itch modality. Knowledge on response generalization can help to prevent and decrease negative effects.
View Article and Find Full Text PDFItch draws our attention to allow imposing action against bodily harm (e.g., remove insects).
View Article and Find Full Text PDFPain and other somatosensory sensations, such as itch, can be effectively decreased by placebo effects and increased by nocebo effects. There are indications that placebo effects on pain generalize to other sensations and that nocebo effects generalize within itch modalities. However, it has not yet been investigated whether learned effects can generalize within pain stimulus modalities or from pain to itch.
View Article and Find Full Text PDFThis study aimed to identify electrophysiological correlates of nocebo-augmented pain. Nocebo hyperalgesia (i.e.
View Article and Find Full Text PDFTo investigate learning processes underlying nocebo effects on itch, this study measured the efficacy of classical conditioning and observational learning for inducing nocebo effects on cowhage-evoked itch and scratching behaviour. A total of 58 healthy female participants were assigned to classical conditioning, observational learning, or sham conditioning groups. In the classical conditioning group, experimenters associated the application of an inert gel with increased itch intensity themselves.
View Article and Find Full Text PDFPlacebo and nocebo effects can influence somatic symptoms such as pain. For itch and other dermatological symptoms these effects have been far less investigated. This review systematically integrates evidence from both animal (mainly rodents) and human trials on placebo and nocebo effects in itch, itch-related symptoms and conditions of the skin and mucous membranes, and related immune outcomes (e.
View Article and Find Full Text PDFAs well established for patients with chronic pain, patients suffering from chronic itch also exhibit signs of peripheral and central sensitization. This has been linked to parallel neuroplastic sensitization processes. However, for chronic itch, sensitization has not yet been systematically assessed, studied, and hence validated.
View Article and Find Full Text PDFPlacebo and nocebo effects have been shown to influence subjective symptoms such as itch. These effects can be induced by influencing outcome expectations through, for example, combining the application of an inert substance (e.g.
View Article and Find Full Text PDFItch 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.
View Article and Find Full Text PDFActa Derm Venereol
February 2019
This corrects the article DOI: 10.2340/00015555-2823.
View Article and Find Full Text PDFNocebo effects, i.e. reduced treatment effects due to patients' negative expectations, play a role in itch.
View Article and Find Full Text PDFItch and pain share numerous mechanistic similarities. Patients with chronic itch conditions (for instance atopic dermatitis or neuropathic itch) often experience symptoms such as mechanical alloknesis and hyperknesis. These dysesthesias are analogous to the pain-associated phenomena allodynia and hyperalgesia, which are often observed, for example, in neuropathic pain conditions.
View Article and Find Full Text PDFSpecially designed transcutaneous electrical stimulation paradigms can be used to provoke experimental itch. However, it is unclear which primary afferent fibers are activated and whether they represent pathophysiologically relevant, C-fiber mediated itch. Since low-threshold mechano-receptors have recently been implicated in pruriception we aimed to characterize the peripheral primary afferent subpopulation conveying electrically evoked itch in humans (50Hz stimulation, 100μs square pulses, stimulus-response function to graded stimulus intensity).
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