Scar from a thyroidectomy, six weeks after the surgery. (Click photo to enlarge.)
Scar from a parathyroidectomy, one year after the surgery. (Click photo to enlarge.)
Scarring is a part of every surgery and is very important to many patients for a variety of reasons: Scars may be painful, itchy or unsightly. Below is a list of common topical agents that are available over-the-counter for scarring.
Most incisions will heal to a thin, cosmetically acceptable scar without using any of the agents described below. However, if you would like to use a topical agent to improve healing and the cosmetic appearance of your scar, we recommend a silicone-based product. See below for additional details.
If you're in a hurry, you can skip to the summary.
Silicones are synthetic polymers that can be a liquid, gel, or rubber.
Several studies illustrate that treatment of hypertrophic and keloid scars with silicone gel improves the appearance and bulk of the scars, especially in patients with burns. The superiority of one form of silicone gel dressing over another is not clear. Although both silicone gel sheeting and silicone gels improved scars, studies indicate no significant difference between the two forms.
Silicone dressings are believed to decrease scars via wound hydration, increased static charge, and modulation of growth factors.
Materials other than silicones (i.e., polyurethane) have shown to be equally effective in the treatment of hypertrophic scars. Both silicone and non-silicone gel dressings have been effective in reducing scar size, induration, and symptoms, but no significant differences have been noted between treatment with silicone and treatment with non-silicone gel dressings.
Bottom Line: There is good evidence showing the efficacy and safety of topical silicone for the treatment of hypertrophic and keloid scars. Silicone gel may improve the thickness, color, and texture of scars, especially thick ones. Although early treatment is ideal, silicone gel sheeting may still be beneficial for older scars.
Patients who wish to use silicone gel for scar management should apply it to the scar for 8 to 24 hours per day. It may take several months to see improvement.
Vitamin E preparations are probably the most popular for use in improving the cosmetic appearance of scars.
Early studies showed that vitamin E, applied topically, penetrates deep into the dermis and subcutaneous tissue, which is likely what led to the idea that vitamin E may improve wound healing when applied topically. When the skin is injured, free oxygen radicals are released in the inflammatory phase and may affect healing. In theory, Vitamin E could reduce free radicals by its antioxidant activity, thus enhancing wound healing.
Research on the effects of vitamin E on skin healing is sparse. Studies have shown that topically applied vitamin E provides no more effect than other emollient-type ointments, and hydration appears to be its only beneficial effect. Interestingly, topical vitamin E may actually cause more harm than good, possibly worsening a scar' appearance and causing contact dermatitis, contact urticaria, and erythema multiform-like reactions in some patients. A recent report from Widegrow has highlighted the skin irritation and reduced tensile strength caused by vitamin E. Use of vitamin E later on in the scar' maturity (4 to 6 weeks and later) may flatten the scar because of its hydrative capabilities, but it may result in a stretched and weakened scar because of its decreased strength effect on the scar; and if used too early, wound separation can occur.
Bottom Line: Although many patients believe vitamin E speeds wound healing and improves the look of a scar, current research evidence does not support this idea. In fact, studies report adverse effects with use of vitamin E. We discourage patients from using topical vitamin E on healing wounds and scars.
Another popular and heavily marketed over-the-counter scar treatment consists of onion extract in a topical gel, which has been marketed as a product to improve scar appearance and texture (Mederma, Merz Pharmaceuticals).
The mechanism of onion extract seems to reside in its antihistamine properties. The theory behind this is that a compound that blocks histamine release may decrease collagen production by fibro-blasts, resulting in reduced scar volume and normalization of the scar maturation process. The cosmetic result is a decrease in scar redness and hypertrophy.
Wounds treated with Mederma did show significantly better improvement of collagen organization. However, a prospective, double-blind study of Caucasian males demonstrated that the effects of topical onion extract on cosmetic appearance, erythema, and hypertrophy of scars in new surgical scars were equivalent to those of petroleum emollient.
Bottom Line: Products containing onion extract (i.e., Mederma) do not improve scar symptoms and have not shown any benefit over petroleum emollients. Applying this product to scars will probably not cause any harm, but will also probably not improve them.
Honey has been used as a dressing for wounds and burns for centuries.
Honey' effects on wound healing are theorized to be from its antibacterial activity in addition to its hydrating properties.
A review of 22 clinical trials involving more than 2,000 patients concluded that honey rapidly clears existing wound infections and protects against further infection, reduces swelling, minimizes scarring, removes infected and dead tissue, and speeds healing by stimulating new tissue growth.
Bottom Line: More well-designed, double-blind controlled trials in humans are needed, but preliminary studies are promising regarding honey and its wound-healing and scar-improvement properties. Applying honey to a healing wound or existing scar has not been shown to be harmful and may speed healing and improve scar appearance.
What works? The bottom line
To summarize, silicone gel has the most data behind it as an efficacious topical, over-the-counter treatment option for scars, and is an option for patients who want something they can buy themselves. Also, there is probably not any harm, and possibly some benefit, to rubbing honey onto healing wounds and scars.
Further controlled studies involving human subjects are needed for topical, natural preparations for scars, so in the meantime, we recommend that patients not waste time or money on other “natural” products that claim to improve the look of scars.
Sample Products: Silicone-Based Scar Therapy
We do not endorse any particular silicone gel over another; the products below are simply examples of brands that are available over the counter at the time of this posting.
Cica-Care gel sheeting (Smith and Nephew)
Mepiform (Molnlycke Health Care)
Kelo-cote (Alliance Pharmaceuticals)