Treatment of Keloid Scars: Silicone Sheets vs Silicone Gel
For keloid scars, both silicone gel sheets and liquid silicone gel are acceptable first-line topical options, though the evidence supporting either modality is of very low quality and shows uncertain clinical benefit. When choosing between them, liquid silicone gel offers practical advantages for irregular surfaces, facial areas, and pediatric patients where adherence to sheets is problematic 1.
Evidence Quality and Limitations
The current evidence base for silicone therapy in keloids is severely limited:
- A 2023 Cochrane review identified only 2 RCTs (36 total participants, 76 scars) comparing silicone gel sheeting to no treatment, non-silicone dressings, or triamcinolone injections 2
- All evidence was rated as very low certainty due to high risk of bias, indirectness, small sample sizes, and imprecision 2
- The review concluded there is insufficient evidence to demonstrate whether silicone gel sheeting makes any difference in keloid treatment compared to alternatives 2
Clinical Effects When Silicone Is Used
Despite weak evidence, observational data suggests potential benefits:
Symptom Relief
- Pain and pruritus typically decrease after 4 weeks of silicone gel sheeting application and may disappear by 12 weeks 3
- Symptom improvement may occur through reduction in mast cell numbers and altered Fas antigen expression in lesional fibroblasts 3
Scar Appearance
- Reduction in scar redness and elevation requires approximately 12 weeks of continuous use 3
- One study showed mean scar area ratio of 0.98 (range 0.78-1.27) after 6 months, indicating minimal change 4
Practical Application Considerations
Silicone Gel Sheets
- Require placement directly on the keloid scar and maintenance at all times 4
- Should be replaced every 4 weeks for optimal effect 4
- Common problems include maceration, rashes, pruritus, and infection 1
- Difficult to apply on irregular surfaces, face, upper chest, and in pediatric patients 1
- Challenging to achieve adequate compression and occlusion in certain anatomical regions 1
Liquid Silicone Gel
- Applied twice daily to overcome difficulties with sheet application 1
- After 90 days, showed significant improvement in volume decrease, reduced inflammation and redness, and improved elasticity in hypertrophic scars 1
- Better tolerated for facial areas, upper chest, and irregular surfaces where sheets are impractical 1
First-Line Treatment Recommendation
Intralesional triamcinolone acetonide (10-40 mg/mL) remains the most commonly used and recommended first-line treatment for keloids, with higher concentrations (40 mg/mL) recommended specifically for keloids 5. Silicone products should be considered adjunctive or alternative options when corticosteroid injections are contraindicated or refused.
Monitoring and Adverse Effects
When using corticosteroid injections (the preferred first-line therapy):
- Monitor for local adverse effects including atrophy, pigmentary changes, telangiectasias, and hypertrichosis 5
- Assess for systemic absorption with repeated injections 5
Prevention Strategy
For individuals with personal or family history of keloids, prevention is the best strategy 5:
- Caution patients about any procedures causing skin trauma 5
- Watch for infections, which can be treated with standard topical or systemic antibiotics 5
Clinical Bottom Line
Given the very low-certainty evidence, if you choose to use silicone therapy, select liquid silicone gel for facial keloids, irregular surfaces, or pediatric patients where adherence is challenging 1. Use silicone gel sheets for flat, accessible areas where the patient can maintain continuous application 4. However, recognize that well-designed studies are needed to reduce uncertainty around decision-making in silicone use for keloids 2, and intralesional corticosteroids remain the evidence-based first-line treatment 5.