Scarring is a normal part of healing. Every wound and surgical incision will heal with a scar. The challenge is to try to minimise the adverse effects of scarring, such as an unsightly scar or scar tethering that restricts movement.
After an injury to the dermis (the lower layer of the skin) the body deposits tissue that is rich in collagen. Over the following months the tissue accumulates, increasing in height, firmness and redness. This is why a new or recent scar looks more obvious than an old scar.
The scar then stabilises (typically over 6-9 months) and then begins to flatten, soften and become paler. A scar will always be present and can never completely disappear - although it is possible to have a scar that is not noticeable to the casual glance or, occasionally, even on very close inspection.
Abnormal scarring commonly involves either hypertrophic scarring or keloid scarring. Both are manifestations of overexuberant scarring, where the body makes too much collagen.
Incorrect placement of scars can also lead to poor functional or cosmetic outcomes. If a scar is placed longitudinally in the skin across a joint it tends to contract and impair the movement of the joint.
In hypertrophic scarring the scar tissue builds up more than is normal, and takes a much longer time course to resolve.
- Linear hypertrophic scars are red, raised and confined to the original borders of the incision. They usually develop in the weeks after surgery and can continue to increase in size over the following few months. These often improve with the passage of time.
- Widespread hypertrophic scars are red, raised and confined to the origianl borders of the injury. They are widespread because of the wide area affected by the initial injury, such as in a burn.
Keloid scar tissue does not follow the normal pattern of evolution, stabilisation and involution of normal scar tissue. Keloid scars are raised and usually itchy. They extend beyond the borders of the original injury, spreading to involve surrounding normal skin. They can develop spontaneously and up to a year after injury. They don't get better spontaneously. If they are cut out surgically they tend to return. While they are much more common in people with black or Asian skin-types, they can also occur in Caucasians. There is a familial tendency to them, which is estimated to affect <6% of the population (naturally this will vary according to the population).
Why do hypertrophic and keloid scars happen?
There are many theories, but we don't know for sure. The theories include excessive skin tension, inflammation, bacterial colonisation, foreign body reaction and abnormal responses of a person's fibroblast cells (a fibroblast is a type of skin cell).
While we don't know why hypertrophic and keloid scars happen we do have ways to reduce and minimise bad scarring.
Sun protection is always wise, but it is especially important to keep healing scars out of the sun. Sun exposure is detrimental to healing and is also likely to result in pigmentation changes (under or over pigmentation) within the scar.
Silicone gel sheeting
Silicone gel sheeting is the standard of care for the treatment of hypertrophic scars. Numerous randomized, double-blind studies have shown that silicone gel sheeting is effective in the treatment of hypertrophic scars and small keloids. It is thought to work through a combination of splinting, occlusion, hydration and local temperature alteration.
Silicone gel sheeting is painless to use and can be used preventatively on surgical wounds once the sutures are removed. It is advisable to wear the sheeting for a minimum of 12 hours each daily, and preferably for 24 hours a day. It is continued for several weeks post operatively.
80-100% of patients show significant improvement in their hypertrophic scars with silicone. In patients with keloids the rate of significant improvement is less, at 35%.
Silicone gel is also available in an ointment or liquid form. This is effective and particularly applicable for the occasional body areas where the gel sheeting is impractical. Silicone gel sheeting is much more commonly used in hand and wrist surgery practice than the liquid or ointment form. It is commonly held in position with a light elastic bandage or tape, which applies light compression.
If you are interested in reading product information about silicone gel sheeting the NewGel+ website is from a company that offers online purchase of silicone sheeting in Australia.
***please note Melbourne Hand Surgery has no association with NewGel+ and receives no benefits from providing the NewGel+ link. This link is provided for convenience and interest only. Other commercial products that you may wish to investigate are CICA-CARE silicone gel sheeting (a self-adhesive occlusive silicone sheet, wash & reuse for up to 28 days), Siltape (an adherent conformable silicone tape, replace at least every 7 days) and Kelo-cote ointment/liquid. Melbourne Hand Surgery has no links with the companies that produce these products***
Corticosteroid injections into the scars have been shown to be effective in scar treatment in many randomised, prospective trials. Response rates vary from 50-100%, with a recurrence rate of 10-50%.
Corticosteroid injections into the scars are first line therapy for keloid scars and second line therapy for hypertrophic scars. They are commonly used in combination with other therapies (such as surgery and silicone sheeting). Possible side effects of corticosteroid injections include skin atrophy and pigment changes at the site of injection.
Compression is the first line treatment for widespread hypertrophic scars that result from burns injuries. This generally involves wearing a compression garment for at least 6 months. The longer the treatment, the more effective it is.
Steristrips/ microporous tape
Adhesive microporous tape applied to fresh incisions for up to 6 weeks after surgery is moderately useful in preventing hypertrophic scarring.
If you have a troublesome hypertrophic or keloid scar surgical scar revision may be appropriate, when combined with other treatments, to improve the scar.
Radiation therapy has been used to treat severe keloids, but it carries significant risks (such as the later development of cancer) and is not routinely recommended or used.
Results from laser therapy to treat scars have been largely disappointing. It is more effective in combination with other treatments (such as silicone sheeting) and currently its main role is in reducing the redness of scars and in flattening mild scars.
Guidelines for the surgical management of abnormal scars
• combination therapy—eg, surgery and corticosteroids— is more effective in preventing recurrence than any single modality
• for small scars, surgical excision and corticosteroids are appropriate therapy
• for moderately large scars, pressure therapy should be added to the surgery-steroid combination
• for very large, treatment-resistant scars, the best results are reported with a combination of surgery and postoperative radiotherapy