Assessment of intralesional injection of botulinum toxin type A injection for hypertrophic scars

Background: Hypertrophic scars are dermal fibroproliferative disorders that typically develop after a skin injury heals. They can cause physical, psychological, and cosmetic problems. The management of such scars remains a matter of debate due to lack of effective treatment methods and the inability to prevent recurrences. Recent reports have demonstrated that botulinum toxin type A improves wound healing so it may play a role in treating hypertrophic scars. Aims: We assessed the effectiveness of intralesional botulinum toxin type A injection for treating hypertrophic scars. Methods: This prospective clinical study included twenty patients with hypertrophic scars. Intralesional injection of botulinum toxin type A was given once a month for three months with a follow-up period of six months. Each lesion was injected until slight blanching occurred. Therapeutic satisfaction of the patient and physician were recorded. Lesions were assessed for erythema, itching and pliability. Each item was assessed on a 5-point scale. Results: Therapeutic satisfaction was recorded as 'good' in 14 patients and 'excellent' in the remaining six. The mean erythema score decreased from 3.2 to 1.0, the mean pliability score from 3.3 to 0.8 and the mean itching score from 2.7 to 0.7. All of these were statistically significant. Limitations: A larger sample size and longer follow-up period would have given a better evaluation but was not feasible due to the high expenses involved. Conclusion: Botulinum toxin type A is a novel and promising therapy for hypertrophic scars with few side effects.