Treatment of Hypertrophic Scars Using Fractional CO2 Laser Alone in Comparison With Adding Botulinum Toxin Either Through Intralesional Injection or Assisted Drug Delivery

Burn injuries represent a major global health concern, often resulting in long term physical, psychological, and social consequences. Among the most challenging sequelae are hypertrophic scars, which arise from abnormal wound healing characterized by fibroblast hyperactivity, excessive collagen deposition and impaired extracellular matrix remodeling. These scars not only compromise skin pliability and aesthetics but also restrict mobility, leading to functional disability and reduced quality of life.

Traditional management strategies including surgical excision, corticosteroid injections, silicone gel, pressure therapy, and radiation have shown variable efficacy, with high recurrence rates and limited patient satisfaction. In recent years, minimally invasive modalities such as fractional CO2 laser therapy have gained prominence for their ability to remodel scar tissue and improve texture. Concurrently, botulinum toxin type A (BTXA) has emerged as a promising antifibrotic agent, exerting its effects by reducing wound tension, modulating fibroblast activity, and regulating collagen synthesis.

The integration of fractional CO2 laser with BTXA, delivered either intralesionally or via laser assisted drug delivery, offers a novel therapeutic approach aimed at enhancing scar pliability, contour and patient comfort. This study investigates the comparative efficacy of these modalities in the treatment of post burn hypertrophic scars, providing evidence to guide optimized clinical practice.

Inclusion criteria

• Scar Type: Clinically diagnosed hypertrophic burn scar not less than 4.5 cm
• Minimum Scar Size: 4.5cm x 1 cm
• Scar duration: At least 1 month old and not exceed 6 months.
• Fitzpatrick Skin Type: II to IV
• No Recent Scar Treatment: No scar treatment within the past 6 months
• Healthy Skin: No active skin infections in the treatment area
• Normal Neuromuscular Function: No history of neuromuscular disorders or medications affecting muscle function.

Exclusion criteria

• 1) Pregnancy /Lactation: Pregnant, lactating, or planning pregnancy within 6 months 2) patients did previous intervention for the scar for the last 6 months 3) Bleeding Disorders: Known cases of bleeding disorders 4) patients with allergic reaction to botulinum toxin or with neuromuscular junction diseases (eg, myasthenia gravis) 5) patients on medication that decrease neuromuscular transmission (eg, aminoglycosides, penicillamine, quinine, and calcium channel blockers).