Pleasant Touch Perception in Persistent Pain.

Overview

The goal of this observational study is to learn how individuals with chronic pain experience pleasant touch and how often they are exposed to such touch in their daily lives. The study also aims to examine how these experiences relate to pain sensitivity and body awareness. The main questions it aims to answer are: How is the perception of pleasant touch associated with central sensitization and interoceptive awareness in individuals with chronic pain? Does the perception of pleasant touch differ between individuals with different dominant pain mechanisms (nociceptive, neuropathic, and nociplastic)? Participants referred to a specialist Pain Clinic in Västra Götaland as part of their regular care will be invited to take part. Those who consent will complete online questionnaires assessing pain, experience and exposure to touch, interoceptive awareness, and central sensitization. Clinical data such as pain diagnosis and medical history will also be collected.

This observational study aims to investigate how individuals with chronic pain experience pleasant touch and how these experiences relate to central sensitization, interoceptive awareness, and different pain mechanisms. Participants referred to the Pain Clinic in Västra Götaland as part of their regular care will be invited to participate. After receiving written and oral information and providing informed consent, participants will complete digital questionnaires via a secure electronic data capture system (REDCap). The questionnaires assess experience and exposure to pleasant social touch, central sensitization (Central Sensitization Inventory, CSI), interoceptive awareness (Multidimensional Assessment of Interoceptive Awareness, MAIA-2), and pain intensity (Numeric Pain Rating Scale, NPRS). A newly developed questionnaire will be used to assess perception and exposure to social touch, including qualitative components. Clinical data will be collected during routine physician visits and include pain diagnosis, pain distribution, symptom severity, comorbidities, and medication use. Questionnaire data and clinical data will be linked using participant ID numbers. Treating physicians will not have access to questionnaire responses to reduce the risk of bias. Additional data may be obtained from the Swedish National Registry for Pain Rehabilitation (NRS), where applicable. A total of 100 participants will be included. Based on previous registry data and similar studies, subgroup sizes are expected to be sufficient to allow comparisons between individuals with different dominant pain mechanisms (e.g., nociceptive, neuropathic, and nociplastic pain).