siRNA Microneedle Patches for Ear Keloid Post-Surgical Scars

The Vancouver Scar Scale (VSS) is a validated clinician-reported instrument that is a measure of scar severity comprising 4 domains assessing scar appearance and physical characteristics. The scale evaluates Vascularity (from 0 to 3), Pigmentation (from 0 to 2), Pliability (from 0 to 5) and Height (from 0 to 3). Each domain is assigned an individual score and combined to provide a total scar severity score ranging from 0 to 13, with higher values representing greater scar severity and poorer scar appearance. Changes in score over time may be used to assess response to treatment, with reductions in score representing clinical improvement. Score at baseline (post-surgical scar immediately post CO2 laser surgery) and at each review visit will be compared.

The Scar Cosmesis Assessment and Rating (SCAR) scale is a validated clinician-reported instrument that is a measure of post-surgical scar quality comprising multiple domains assessing scar appearance, symptoms, and overall cosmetic outcome. The scale evaluates Scar Spread (from 0 to 4), Erythema (from 0 to 3), Dyspigmentation (from 0 to 2), Track or suture marks (from 0 to 1), Hypertrophy or atrophy (from 0 to 3), Overall impression (from 0 to 1), and patient rated bothersome itch and pain over the preceding 24 hours (Yes or No). Individual domain scores are combined to provide a total assessment of scar severity and cosmesis, with higher values representing poorer scar appearance and greater symptom burden. Changes in score over time may be used to assess response to treatment, with reductions in score representing clinical improvement. Score at baseline (post-surgical scar immediately post CO2 laser surgery) and at each review visit will be compared.

The Detroit Keloid Scale (DKS) is a validated, clinician- and patient-reported instrument to assess the severity and treatment response of keloids. It is designed specifically for keloid scars and evaluates both objective scar characteristics and patient symptoms. The DKS has two components - the Observer Keloid Assessment (clinician-reported domains of location, height and surface area) and Patient Keloid Questionnaire (patient-reported domains of pruritus, pain, contracture/limitation to range of motion and quality of life). Scores from each domain are combined to provide a total assessment of keloid severity, with higher values representing greater disease severity and symptom burden. Changes in score over time may be used to assess response to treatment, with reductions in score representing clinical improvement. Score at baseline and at each review visit will be compared.

Keloid recurrence will be defined by Height score of at least 1 on the Observer Keloid Assessment of the DKS. The keloid wound bed will be flat post-CO2 laser surgery and increase in height is taken to be an early marker of keloid recurrence.

The recurrence rate in each arm will be measured. It is calculated as the number of patients with keloid recurrence divided by the total number of patients in the treatment arm.

For patients with recurrent ear keloid, time to ear keloid recurrence will be measured. It is calculated as the time from CO2 laser surgery (denoted as day 0) to time of first detection of keloid recurrence in days.

For patients with recurrent ear keloid, secondary rescue treatment will be measured in terms of treatment modality offered (such as repeat CO2 laser surgery, intralesional steroid injection) and response (resolution, partial response, no response).

Patients in the experimental arm who will receive the siRNA microneedle patches will fill in a questionnaire on the usability of the siRNA microneedle patches. The questionnaire evaluates 1) degree of acceptability of microneedle patches (four options of very acceptable, acceptable fair or not acceptable), 2) whether patients will use the microneedles patch again in the future to treat any future post-surgcial scars (Yes/No response, with further open ended elaboration), and 3) areas of improvement to suggest if any (optional open ended).

Patients will be monitored for any adverse effects from the CO2 laser surgery, intralesional corticosteroid injections and/or the siRNA microneedle patches, such as but not limited to - dyspigmentation, skin atrophy, telangiectasia, edema, infection, contact dermatitis, ulceration, necrosis.