The creation of a scar is the end result of the wound healing process, specifically the third phase of wound healing when new collagen is laid down. It is commonly believed that the inflammatory component of the wound healing process is essential for not only healing of the wound but the development of a scar as well. As a result, potential scar therapy innovations are looking at inflammatory mediators in the hope that less scar will be formed by controlling the inflammatory process of the wound healing sequence.
Currently available scar reducing therapies include steroids (triamcinolone injections), 5FU (5-fluorouracil, bleomycin, laser therapy, silicone gel sheeting, pressure therapy, radiation, and cryotherapy. All of these have been shown to have some effect and can be part of many contemporary scar treatment strategies.
I like to rank these agents based on their risk of potential side effects. No risk therapies would be silicone gel sheeting, topical silicone gel and pressure therapy. Despite their frequent touting and use in scars, the actual evidence that they really do prevent or improve poor scarring is very weak. But their no risk of side effects makes them popular. Low risk therapies include laser and pulsed light treatments. Their benefits are more theoretical (currently) than proven, but other than the potential for some mild hypopigmentation they have very little risk to their use in experienced hands. Injection therapies, such as steroids, and cryotherapy fall into the moderate risk use category. They do have a proven track record of success which accounts for their intial use in many problematic scars. But they frequently have some side effects as well including subcutaneous fat atrophy, skin thinning, and hypopigmentation. Controlled and limited use is the key to avoid these potential problems. Overdosing or chronic use of injectable steroids will eventually exhibit these adverse cosmetic outcomes. Higher risk strategies include surgical scar revision (excision) and radiation. While both can work well, they are usually at the end-stage of treatment options and are reserved for the most problematic of scars or those that have failed previous less risky treatment options. In the worst of scar problems, a combination of treatments is often done, such as surgical excision and steroids or surgical excision and radiation. This combined approach is almost always reserved for the pathologic true keloid of which recurrence is high no matter what is tried.
Emerging scar-reducing therapies are coming from the TGF-beta family of growth factors. Several such containing products are in clinical trials currently. TGF-beta is a known key agent in the inflammatory wound healing cascade and offers the theoretical hope of controlling inflammation and scar production but perhaps with less side effect than traditional injectable steroids. COX-2 inhibitors, a well known mechanism in many non-steroidal anti-inflammatory drugs, is of interest topically. It works by modulating prostaglandin production which can potentially limit the amount of collagen production and possibly scar formation. Both of these approaches are of great interest currently but are years away from becoming an actual clinical therapy.
Dr. Barry Eppley
Indianapolis, Indiana