Botulinum Toxin Applications in Scar Management

Scar formation following surgical or traumatic skin injury remains a significant clinical challenge, with hypertrophic scars and keloids affecting both function and appearance. Botulinum toxin type A (BTxA), traditionally deployed in aesthetic medicine to reduce dynamic rhytides, has emerged as a promising adjunct in scar modulation. By inducing temporary muscle paralysis and reducing mechanical tension at wound edges, BTxA limits fibroblast activation, modulates local inflammatory mediators and alters collagen deposition. In parallel, mechanistic studies indicate that BTxA can interfere with neurogenic inflammation pathways, diminishing substance P-mediated stimulation of scar tissue. Clinical investigations have explored its use in diverse anatomical sites—from facial repairs to mastectomy and thyroidectomy incisions—demonstrating improvements in scar width, vascularity, pliability and patient satisfaction. Optimal outcomes depend on precise timing and dosing, with split-scar trials underscoring a dose–response relationship. As understanding deepens regarding the interplay between neuromuscular blockade, growth factor expression and extracellular matrix remodelling, BTxA is poised to become an integral component of tailored scar-management protocols worldwide.

Research from Nature Portfolio

Recent work has evaluated the impact of early postoperative BTxA dosing on surgical scar appearance using a split-scar design. Patients undergoing elective procedures received high- and low-dose injections into respective halves of the same incision immediately after closure. At six months, high-dose sites exhibited superior scores on a validated scar assessment scale and higher patient satisfaction, without an increase in adverse events. These findings underscore the importance of dose optimisation and suggest that within therapeutic ranges, higher concentrations of BTxA confer greater reductions in scar hypertrophy and improve aesthetic outcomes.

Botulinum Toxin Applications in Scar Management publication trend

The graph below shows the total number of articles in botulinum toxin applications in scar management across all publications each year (not limited to Nature Index journals).

Technical terms

Botulinum toxin type A (BTxA): a neurotoxic protein that reversibly inhibits acetylcholine release at the neuromuscular junction, reducing muscle contraction and mechanical stress on healing wounds.

Vancouver Scar Scale (VSS): a clinical tool scoring scars for pigmentation, vascularity, pliability and height to quantify severity and treatment response.

Patient and Observer Scar Assessment Scale (POSAS): a dual-component scale capturing both clinician-rated and patient-reported scar characteristics, including pain, itch and overall impression.

Split-scar experiment: a study design in which different treatments are applied to separate halves of the same wound, enabling direct intra-patient comparison.

Modified Stony Brook Scar Evaluation Scale (SBSES) and Manchester Scar Scale (MSS): validated instruments assessing cosmetic and functional attributes of postoperative scars, such as color match, contour and texture.

References

1. Efficacy of Botulinum Toxin Type A for Prevention of Post-Mastectomy Scar in Transmen: A Prospective, Randomized Study. Toxins (2023).
2. Botulinum Toxin to Improve Results in Cleft Lip Repair: A Double-Blinded, Randomized, Vehicle-Controlled Clinical Trial. PLOS ONE (2014).
3. Effect of Botulinum Toxin A on Scar Healing after Thyroidectomy: A Prospective Double-blind Randomized Controlled Trial. Journal of Clinical Medicine (2020).
4. The effect of botulinum toxin injection dose on the appearance of surgical scar. Scientific Reports (2021).
5. Dramatic Effect of Botulinum Toxin Type A on Hypertrophic Scar: A Promising Therapeutic Drug and Its Mechanism Through the SP-NK1R Pathway in Cutaneous Neurogenic Inflammation. Frontiers in Medicine (2022).