Long lauded for its ability to reduce the appearance of wrinkles, botulinum toxin is now being considered for reducing scarring.
By using botulinum toxin to denervate underlying muscle and immobilize tension―which increases inflammation, fibrosis, erythema and scar size―scarring can potentially be reduced, say researchers writing in a review published in the Journal of Drugs in Dermatology.
The review, published in the September issue of the journal, highlights several success stories of the toxin’s use in improving scarring. Dr. Domenico Vitarella, Ph.D., author of the review and a researcher with Bonti, Inc., says that although the FDA has not approved botulinum toxin for this specific use, “the treatment seems to be gaining momentum among physicians.”
In 2006, researchers reported the first blinded, placebo-controlled, randomized study for scar reduction on 31 patients with forehead wounds. The patients either had traumatic forehead lacerations or were undergoing plastic surgery for the removal of a mass on the forehead.
Patients received a botulinum toxin or placebo injection in the musculature adjacent to their lesions within 24 hours of surgery. Afterwards, those who received the botulinum toxin received a median Visual Analog Scar Score (VASS) of 8.9 while placebo recipients received a median score of 7.2.
A separate study reported in 2013 described 24 patients with facial wounds who were randomized to receive no injection or the injection of botulinum toxin within 72 hours of surgery. At one-year follow-up, the group treated with botulinum received a media Vancover Scare Scale (VSS) score of 8.25, while the control group received median scores of 6.35.
In his review, Dr. Vitarella writes that despite these successes, much remains to be explored. For one, larger clinical trials are still needed to gain FDA approval.
“Physicians are experimenting and using this product off-label for scar reduction [right now,]” Dr. Vitarella says. “Bonti believes this is a great area of study and this can work and help [reduce scarring], but we are not able to advocate for physicians doing this until there’s official FDA approval.”
Optimal dosing remains to be determined as well so as to not cause patients functional problems, particularly when botulinum is applied to the lower face.
In one case, for example, a woman experienced reduced oral sphincter function resulting in spillage of liquids and mild dysarthria for four weeks after an injection to the lower lip. The 26-year-old had received surgical repair and botox to the perioral musculature when her lip was crushed in a motor vehicle accident.
The patient was required to maintain a soft diet for 10 days after the procedure. She eventually returned to normal eating habits and at six months, a scar was hardly perceptible.
Vitarella believes functional problems caused by the botulinum toxin’s immobilization of muscles may be avoided if the toxin can be reconfigured to have a shorter duration. His company is currently developing and testing the product EB-001 for optimized scar reduction.
Akash Dhawan, Sunil Dhawan MD, Domenico Vitarella PhD. "The Potential Role of Botulinum Toxin in Improving Superficial Cutaneous Scarring: A Review," the Journal of Drugs in Dermatology. September 2018.
Holger G. Gassner MD, Anthony E. Brissett MD, Clark C. Otley, MD, et al. "Botulinum Toxin to Improve Facial Wound Healing: A Prospective, Blinded, Placebo-Controlled Study," Mayo Clinic Proceedings. August 2006. DOI:https://doi.org/10.4065/81.8.1023
Makram Ziade, Sophie Domergue, Dominique Batifol, et al. "Use of botulinum toxin type A to improve treatment of facial wounds: A prospective randomised study," JPRAS, February 2013. DOI: https://doi.org/10.1016/j.bjps.2012.09.012
Holger G. Gassner, MD; David A. Sherris, MD; Oren Friedman, MD. "Botulinum Toxin–Induced Immobilization of Lower Facial Wounds," JAMA Facial Plastic Surgery. March/April 2009. DOI:10.1001/archfacial.2009.3