Affective Touch Reduces Electrically Induced Itch Experience

Abstract

Introduction: Itch is a common symptom in dermatologic and other diseases and can have a severe impact on quality of life and mental health. As a proportion of patients with itch-symptoms is resistant to commonly used anti-histamine treatments, development of new treatments is desirable. Past research on pain, itch and affective touch (i.e. slow, gentle stroking of the skin activating C-tactile fibers) revealed an inhibitory relationship between affective touch and pain and between pain and itch. Given the overlap in neural processing between these three sensory submodalities, a possible interaction between affective touch and itch might be expected. This study investigated whether there is a relationship between itch and affective touch, and if so, whether affective touch inhibits itch.Methodology: Itch was electrically induced with the use of electrodes that were placed at the ventral side of the wrist of 61 participants. A within-subject design was conducted with two conditions. An experimental -affective touch- condition (stroking the forearm with a soft brush at 3 cm/s) and a control -non-affective touch- condition (stroking the forearm with a soft brush at 18 cm/s). Touch was applied on the dorsal side of the forearm, the same arm as were the electrodes were placed. For each condition itch was induced for 20 min, with every 2 min a VAS-scale measurement of the level of experienced itch.Results: Both types of touch reduced the experienced itch compared to baseline (p < 0.01, partial η2 = 0.67). However, affective touch had an additional significant relieving effect compared to non-affective touch (p = 0.03, partial η2= 0.08). The alleviation of itch started after 2 min of stroking and continued to increase up till 6 min, where after the relieving effect stabilized but still persisted.Conclusion: This finding suggest that affective touch, as with acute pain, has a relieving effect on electrically induced itch.

CT-optimal touch and chronic pain experience in Parkinson’s Disease; An intervention study

“…If so, this might indicate that the pain-relieving effect is merely related to having a concurrent pleasant sensation, rather than the specific activation of the CT-system. However, previous studies of von Mohr, Krahe ´ [22] and Meijer, Schielen [26] into the effect CToptimal touch on respectively acute pain and itch have failed to show such a relationship between the perceived pleasantness of CT-optimal touch and its relieving effect, suggesting it is not the experienced pleasantness per se that causes the pain reduction. Finally, if CT-optimal touch can ameliorate pain this might also positively influence mood and affect [27].…”

The Experience of Itch in Autistic Adults: An Online Survey

“…Somatosensory interoceptive modalities have a common neurobiology: peripheral, unmyelinated c-fibres synapsing in the superficial layers of spinal cord dorsal horn. They are also known to interact at multiple levels of the nervous system (Andersen et al, 2017;Chen & Sun, 2020;Cranfill & Luo, 2021;Davidson & Giesler, 2010;Koch et al, 2018, p. 201;Li et al, 2021;Meijer et al, 2021;Murota & Katayama, 2016;van de Sand et al, 2018;Wolters et al, 2019). Many theories of autistic perception predict the existence of interoceptive differences (Proff et al, 2022;Quattrocki & Friston, 2014), and in light of the multimodal interoceptive differences found in autistic people (Proff et al, 2022), it would be surprising if itch experience were unaffected.…”

The skin‐brain connection and pleasant touch as supportive care for psychocutaneous disorders

“…While discriminative touch mainly elicits the activation of somatosensory cortex, 41 the main target in the brain for the processing of these CT‐mediated pleasant properties of touch is the insular cortex, which plays an important role in the processing of emotions 48 . Affective touch reduces activation of areas related to pain processing, namely the insula and anterior cingulate cortex, and reduces electrically‐induced itch, through activation of regions involved in pleasure and reward 49 . Furthermore, the neural basis of affective touch and pain has been reviewed and CT‐optimal touch appears to be beneficial in reducing acute pain 50–52 and chronic pain 53 .…”

“… 48 Affective touch reduces activation of areas related to pain processing, namely the insula and anterior cingulate cortex, and reduces electrically‐induced itch, through activation of regions involved in pleasure and reward. 49 Furthermore, the neural basis of affective touch and pain has been reviewed and CT‐optimal touch appears to be beneficial in reducing acute pain 50 , 51 , 52 and chronic pain. 53 Gentle stroking has been shown to decrease noxious‐evoked brain activity in human infants, which is similar to that observed when adults experience pain.…”