A scar is a change in the skin left by a wound or injury to the surface of the skin. It is composed of new connective tissues that replaced lost substance in the skin. Scras produce a structural change in the deeper layer of the skin, which is perceived as alteration in the architecture of the normal surface features.
How do scars form?
When the skin is wounded and there is a break in the body’s tissues, the body produces more of a protein called collagen, as part of the healing process. Collagen builds up where the tissue has been damaged, helping to heal and strengthen the wound.
For a period of about three months or longer, new collagen continues to form and blood supply increases, causing the scar to become raised, lumpy and red. Some collagen then breaks down at the site of the wound, the blood supply reduces and the scar gradually becomes smoother, softer and paler.
Although scars are permanent, they can fade over a period of up to two years. It is unlikely they will fade any more after this time.
Skin wounds can be caused by many things, including:
- accidental injuries
- burns and scalds
- intentional harm
Where do scars form?
Scarring is unpredictable and varies from person to person. Certain areas of the body are more at risk of scarring, such as the chest, back, ear lobe and the shoulder.
Scars that form on the knees and shoulders can appear stretched or widened as a result of the healing process occurring over movable joints.
Types of scars
Scars on the skin may appear when a cut or other injury is in the process of healing. The different types of scars vary in appearance.
Flat, pale scars
The most common type of scar is the flat, pale scar that forms as a result of the body’s natural healing process. These scars are not usually painful, although they may be itchy for a few months. They can also be quite dark in colour and unsightly.
A keloid scar is an overgrowth of tissue that occurs when too much collagen is produced at the site of the wound and the scar keeps growing, even after the wound has healed.
Keloid scars are often raised above the skin, itchy, painful, and appear larger than the original wound. It can cause a burning sensation and feel tender to touch, and can restrict movement if they are tight and near a joint. It feels hard and have a “rubbery” texture, although some keloids can form soft lumps.
The areas of the body where keloid scars are more likely to form include:
- the area around the breastbone (sternum)
- the upper arms and shoulders (deltoids)
- the upper back
- on the ear lobes
Hypertrophic scars are the result of an imbalance in the production of collagen in a healing wound. Unlike keloid scars, they do not extend beyond the boundary of the original wound, but may continue to thicken for up to six months. Hypertrophic scars can have this appearance for many years.
Pitted or sunken scars (atrophic or “ice-pick” scars)
Some scars caused by skin conditions such as acne and chickenpox can have a sunken or pitted appearance. They can also be the result of an injury, which may have included the loss of underlying fat.
Scar contractures are commonly caused by burns. These occur when the skin “shrinks”, leading to tightness and a restriction in movement.
What are stretch marks?
Stretch marks are skin markings that can look similar to long thin scars, but they are actually formed in a different way.
Some treatments – such as laser therapy – are not widely available on the NHS, so you will need to pay for them privately.
Corticosteroid injections are used to treat some keloid and hypertrophic scars.
Multiple small injections are made into the scar to reduce any swelling (inflammation) and to flatten the scar. Depending on the type of scar, these may need to be repeated. Injections are usually given on three occasions, at four- to six-week intervals, to assess your body’s response. Treatment may sometimes continue for several months if the scar is improving.
This treatment cannot remove scars, but it can improve their appearance.
Silicone gels or sheets
Silicone gels or sheets are available from some pharmacies. They are used on healing skin (not open wounds) to reduce redness and to try to minimise hypertrophic or keloid scars.
To be effective, silicone gels or sheets should be placed over the scar for 12 hours a day, for at least three months.
Surgery for scars
Surgery can sometimes improve the appearance of scars, as it can be used to:
- change the positioning of the scar
- change the width or shape of the scar
- release a tight scar that is close to a joint, to improve movement
Surgery alone is not advised for keloids, as they tend to grow back larger. Surgery for keloids is often combined with corticosteroid injections at the site of the removed scar immediately after surgery. Some plastic surgeons also add other treatments, such as X-ray therapy and oral antibiotics, to try to minimize the recurrence of a keloid that has been surgically treated. You can talk to your surgeon about this treatment.
Pressure dressings for scars
The aim of pressure dressings is to flatten and soften scars. They are most often used for large burn scars or after skin grafts.
Pressure dressings are usually made from a stretchy, elastic material. They are worn over the scar 24 hours a day, for around 6 to 12 months. They can also be used in combination with silicone gel sheeting, to improve the appearance of scars over a long period of time.
Laser or light therapy (pulses of light) can reduce the redness in a scar by targeting the blood vessels in the excess scar tissue. For some pitted scars, laser surgery (laser re-surfacing) is used to try to make the scar flatter. This involves using a laser to remove the top layers of skin, which stimulates collagen production in the deeper layers.
Dermal fillers are injections (often of a man-made acid) used to “plump up” pitted scars. Treatments can be costly and the results are usually temporary. Repeat treatments are needed to maintain the effect.
Skin needling, which involves rolling a small device covered in hundreds of tiny needles across the skin, is also reported to be helpful, but repeat treatments are often needed to achieve an effect, and results vary considerably.
Scars and skin creams
Although Vitamin E cream is sometimes recommended for the self-management of scars, there is no medical evidence to suggest that it has an effect.
However, the massaging of a moisturiser such as E45 into the scar will keep it from becoming dry and help make it supple.
Scars may be sensitive to the sun. Sunscreen can be used to protect them.