Botulinum Toxin Type E Associated With Reduced Itch and Pain During Wound Healing and Acute Scar Formation Following Excision and Linear Repair on the Forehead: A Randomized Controlled Trial
Among 13 participants, 9 received BoNT/E and 4 received saline. One participant randomized to BoNT/E was excluded from efficacy analyses due to wound dehiscence associated with high tension closure but included in safety analyses (n=9). Participants analyzed for efficacy (BoNT/E, n=8; placebo, n=4) were 58.3% (7/12) male and 100% White (not Hispanic); mean (SD) age was 61.8 (11.39) years. There were no differences in improvement over time between 2.8 ng BoNT/E and placebo on primary measures. However, SCAR subscale items for “itch” and “pain” were favorable for BoNT/E. No participants in the BoNT/E group reported itch, compared with 75% and 50% at days 2 and 8 in the placebo group, respectively. Similarly, 75% of participants in the BoNT/E group versus 100% in the placebo group reported pain on day 2; 25% of participants in the BoNT/E group versus 50% in the placebo group reported pain on day 8. One (1/9, 11.1%) participant who received BoNT/E experienced facial asymmetry due to intraoperative temporal nerve injury before BoNT/E injection. Compared with placebo, a single dose of 2.8 ng BoNT/E was safe and nominally improved itch and pain but not other aspects of wound healing or scar formation. Future studies may assess larger or less well-approximated repairs. This study was limited by the small sample, variability in surgical wound size, fixed dose, and fixed injection paradigm. As a rapid onset neurotoxin, BoNT/E may help improve patient comfort during the acute phase of scar formation.