J AM ACAD DERMATOL
VOLUME 59, NUMBER 4
With any mention of silicone, there will always be those concerned with safety and who argue against its use. There has been controversy about the safety profile but a meta-analysis based on 7 studies performed in 1996 by Hochberg and Perlmutter65 did not reveal any significant relationship between silicone (specifically associated with augmentation mammaplasty) and the development of connective tissue diseases, including systemic sclerosis. Another study that reviewed 524 patients receiving 422.5 mL of silicone through 4756 treatments over 20 years only discovered 4 symptom reports or adverse events. One was ‘‘signs and symptoms of infection,’’ another developed 1-31.5-mm papules 1 cmremote from the injection site without evidence of silicone on histopathology (reported as ‘‘hyperkeratosis’’), a third had ‘‘erythema,’’ and the final was a symptom of ‘‘doughnutting’’ that required shave excision, resulting in localized infection.66 In fact, Barnett and Barnett67 discussed silicone use in relation to acne scarring and provided examples of 5 patients with follow-up up to 30 years posttreatment that demonstrated its efficacy along with its safety and permanence.
There are several silicone products that are available, with the usual difference based on viscosity. The original silicone was 350-centistoke viscosity. Adatosil 5000 is medical-grade silicone of 5000- centistoke viscosity and Silikon 1000 is of 1000- centistoke viscosity. Polydimethylsiloxane gel is a silicone oil with viscosities from 350 to 5000 centistokes and another is Silskin. One that is slightly different from these is Bioplastique. It consists of solid silicone particles (100-400 and 600 m) suspended in polyvinylpyrrolidone gel. There is gradual replacement of the gel with fibrous tissue and native collagen.
Another valuable injectable filler material for acne scars is hyaluronic acid. This substance is a highly hydrophilic, natural, linear polysaccharide (alternating residues of d-glucuronic acid and n-acetyl-dglucosamine) component of connective tissue in all mammals so is not tissue or species specific.68 Hyaluronic acids do not require the initial overcorrection as collagen does because there is less water loss after injection. In addition, it displays isovolemic degradation in which molecules of HA degrade allowing those remaining to absorb more water. Thus, the total volume of gel remains stable. The injectable concentration steadily decreases through reabsorption while the relative volume is essentially unchanged.69 The duration of effect for acne scars is roughly a year or more. Side effects potentially include erythema, edema, bruising, inflammation, delayed reactions, infection, pain, milia or acne, and rare reports of necrosis (most likely technique related).70 There is very low true allergic potential so skin testing is not required although some physicians prefer to do so.
Developed in the 1980s, Hylaform and Hylaform Plus are hyaluronic acid products derived from rooster comb and cross-linked with divinyl sulfone. Hylaform Plus has larger particle sizes. A series of injections into the dermis are required and there are few adverse events, side effects, or allergies.71 Restylane (with Restylane Fine Lines and Perlane), approved in 2003, is a hyaluronic acid (HA) derived from production by Streptococcus equi. All are 20 mg/mL of HA but differ in the particle size and viscosity. Restylane Fine Lines has 200,000 gel particles/mL with the smallest particles, in comparison with Restylane, which has 100,000 gel particles/mL. Perlane has the largest particles and has a concentration of 8 to 10,000 gel particles/mL. Restylane Fine Lines is the least viscous and Perlane is the most viscous and is for deeper injection.72 Captique was introduced in 2004 and is derived from bacterial sources. It is for dermal injection as well. The family of Juvederm products was FDA approved in 2006. They are all derived from S equi and cross-linked with 1,4-butane-diol-diglycidyl ether. Inflammation, erythema, papules, pustules, flushing, and swelling have all been reported but less so than with other hyaluronic acids.73 Dermalive is a 60% hyaluronic acid plus 40% acrylate suspension of 45 to 65 m, irregularly shaped hydroxyethyl methacrylate and ethyl methacrylate particles. Injections are to be done every 3 months to desired effect with approximately 40% retention of each treatment. No skin testing is required prior. Dermadeep is the same composition as Dermalive but the acrylate crystals are larger, 80 to 110 m. Teosyl contains hyaluronic acid microspheres at 15- to 25-mg/mL concentration.
Polyacrylamides compose yet another form of injectable augmentation products and, once again, several products exist. Outline is composed of absorbable hydrophilic polyacrylamide gel particles that are positively charged, thus attracting negatively charged glycosaminoglycans already in the skin such as hyaluronic acid. Similarly, Evolution, positively charged polyvinyl microspheres in hydrophilic gel, also attracts the negatively charged molecules. Bio- Alcamid is a polyalkylimide gel that is 96% water and 4% synthetic polymer that stimulates a fibrous response after injection. Agriform is a 5% water and 95% hydrophilic polyacrylamide gel combination, in contrast to Aquamid, a 97.5% water and 2.5% hydrophilic polyacrylamide gel mixture.
The polylactic acids are a more recent addition to the treatment options available for injection to scars. Previously, these materials were used in suture materials and other treatments. NewFill, the primary brand for Europe, was available in 1999, as freezedried polylactic acid available for reconstitution with water. Poly-L-lactic acid was rebranded in the United States in 2000 as Sculptra.74 A frequent use, other than scars, is in lipoatrophy because of HIV. It is thought to stimulate neocollagenesis over 3 to 6 months and is for long-term augmentation. Side effects are possibly worsened by excess injection material, inadequate duration between injections, or multiple single-session injections. No skin tests are necessary with the use of polylactic acids.
Acne Scarring Tissue Augmentation page 4
Acne Scarring A review and current treatment modalities BACKGROUND and ACNE SCARS ACNE SCARS page 2 ACNE SCAR TREATMENT and MEDICAL MANAGEMENT SURGICAL MANAGEMENT PROCEDURAL MANAGEMENT PROCEDURAL MANAGEMENT page 2 TISSUE AUGMENTATION TISSUE AUGMENTATION page 2 TISSUE AUGMENTATION page 3 TISSUE AUGMENTATION page 4 Light, laser, and energy therapy Light, laser, and energy therapy page 2 Light, laser, and energy therapy page 3 Light, laser, and energy therapy page 4 Conclusion and REFERENCES Manufacturers of brand name drugs mentioned in this article