Introduction
The mechanisms underlying persistent scar pain are not fully elucidated and evidence for the clinical evaluation of scar pain is limited. This pilot observational study investigated participation data and sought to identify objective clinical scar evaluation measures for future trials.
Methods
With ethical approval and consent, adults undergoing planned hand surgery were enrolled from one NHS hospital. At 1- and 4-months post-surgery scar thermal and mechanical pain thresholds were evaluated with quantitative sensory testing; peri-scar inflammation with infrared thermometry and pliability with durometry. Participation data were analysed with descriptive statistics; the association of clinical measures with patient reported scar pain was analysed.
Results
Twenty-one participants (22% eligible patients) enrolled before study closure due to the COVID-19 pandemic; 13 completed follow up. No adverse events or dropouts resulted from clinical scar evaluation. Seventy percent of participants reported undertaking topical, nonprescription scar treatment independently. Neuropathic Pain Symptom Inventory (NPSI) scores were dispersed across the score range, capturing variability in participant-reported scar symptoms. Scar morphology, pliability and inflammation were not associated with scar pain. Differences between scar and contralateral skin in thermal and mechanical pain sensitivity were identified.
Conclusion
People with acute hand scars participate in clinical research and independently initiate scar treatment. Clinical testing of acute post-surgical hand scars is well tolerated. The NPSI demonstrates utility for exploring scar pain symptoms and may support the elucidation of mechanisms of persistent scar pain. Clinical tests of thermal and mechanical and sensitivity are promising candidate clinical measures of scar pain for future trials.