What is a scar?
A scar is a mark that is left on the skin after a wound or an injury to the surface of the skin has healed.
Scars are very common – most people have at least one on their body. They are a natural part of the healing process.
Scars can occur inside and outside the body. For example, they can occur on the internal organs where a cut has been made during surgery, and can develop after certain skin conditions, such as acne and chicken pox.
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 two years. After this time, it is unlikely they will fade any more.
Skin wounds can be caused by many things, including:
- accidental injuries
- burns and scalds
- intentional harm
Read more about the causes of scars.
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, the back, the 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
The different types of scars include:
- hypertrophic scars – red, raised scars that form along a wound and can remain this way for up to five years
- keloid scars – caused by an excess of scar tissue produced at the site of the wound where the scar grows beyond the boundaries of the original wound, even after the wound has healed
- pitted (atrophic or 'ice-pick') scars – with a sunken appearance
- contracture scars – caused by the skin shrinking and tightening, usually after a burn, which can restrict movement
Read more about scar types.
Depending on the type and age of a scar, a variety of different treatments may help make them less visible and improve their appearance.
Scars are unlikely to disappear completely, although most will gradually fade over time.
If scarring is unsightly, uncomfortable or restrictive, treatment options may include:
- silicone gel sheets
- pressure dressings
- corticosteroid injections
- cosmetic camouflage (make-up)
Often, a combination of treatments can be used.
Read more about treating scars.
Scarring, particularly when it is on the face, can be very distressing. It can feel as if you are being stared at. If you avoid meeting people as a result of your appearance, you may become socially isolated. This can lead to feelings of depression.
If you feel that your scars are making you depressed or affecting your daily activities, visit your doctor.
It is not possible to prevent scars from forming, but there are things you can do to help your scar be less visible and heal better, such as immediately cleaning dirt, objects and dead tissue from wounds.
Other ways to improve scarring include:
- avoiding scratching or picking at scabs and spots
- covering wounds with a waterproof ointment (such as Vaseline)
- using silicone gels or sheets to reduce redness and encourage healing
What do scars look like?
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.
At first, a normal scar may be red and look sore, but it will usually fade as the injury begins to heal. If the skin at the edges of the wound has come together neatly, the scar will usually heal as a thin, pale line.
In wider wounds, where more surface skin is missing and more scar tissue is needed to bridge the gap between the edges of damaged skin (such as a bad graze on the knee), the scar may be less neat and may take longer to heal.
Normal scars are not usually painful, although they may be itchy for some months. They can also be quite dark in colour and unsightly.
If you have a darker skin type, scar tissue may fade to leave a brown or white mark. These are often permanent, but can sometimes improve over time. If your skin is tanned, the scar may appear more obvious as scar tissue does not tan and remains pale.
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.
They often have the following characteristics:
- it is often raised above the skin
- it can feel itchy
- it can feel painful
- it can appear much larger than the original wound
- it can cause a burning sensation and feel tender to touch
- it can restrict movement if it is tight and near a joint
- it is raised above the skin
- it is hairless and appears shiny
- it feels hard and has a ‘rubbery’ texture, although some keloids can form soft lumps (such as on the ear lobe after piercings)
- a newly formed keloid scar is red or purple, becoming paler with time
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
A hypertrophic scar is a red, raised scar that forms along a wound and can have the following characteristics for around two to five years:
- it can restrict movement because scar tissue is not as flexible as the original skin
- it heals within the size of the original wound
- the healing tissue is thicker than usual
- it is red and raised initially, becoming flatter and paler with time
Hypertrophic scars can have this appearance for many years.
Pitted scars (atrophic or 'ice-pick' scars)
Some scars caused by skin conditions such as acne and chickenpox can have a sunken or pitted appearance.
Scar contractures are commonly caused by burns. These occur when the skin “shrinks”, leading to tightness and a restriction in movement.
What causes scarring?
Scarring results from the body's natural healing process after body tissue has been damaged.
Tissue damage can occur for a number of reasons, including:
- accidental injuries, such as cuts from falling off a bicycle
- deliberate harm from a weapon or from self-harm
- cuts made during surgery, such as a Caesarean section birth
- bites and scratches from animals or people
- burns and scalds from hot objects or liquids
- body piercings, such as ear or nose piercings
- injections, such as vaccination against tuberculosis (BCG vaccination)
Scarring can also be a side effect or a complication of other conditions. For example, if you have a condition that causes a rash, such as chickenpoxor acne, you may be left with scars where the rash was (more likely if you scratch or pick at the affected areas).
It is thought keloid scarring and hypertrophic scarring may run in families. This means you have an increased risk of developing keloid scarring or hypertrophic scarring if a member of your family has previously had these types of scars.
Internal scarring can be caused by injuries or surgery.
How can I get rid of a scar?
People seek help for scars if they are painful or itchy, if they are unsightly, or if they restrict movement.
Although scars cannot be removed completely, they can often be made less visible. However, more research is required to assess the effectiveness of the different treatments.
Your doctor may refer you to a dermatologist or a plastic surgeon for treatment.
Corticosteroid injections are used to treat some keloid and hypertrophic scars.
Multiple small injections are made into the scar to reduce any inflammation (swelling) and to flatten the scar. Depending on the type of scar, these may need to be repeated. Usually injections are given on three occasions at 4-6 week intervals to assess your body’s response. Sometimes treatment may 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 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.
You can ask your doctor, dermatologist or pharmacist for further advice about a range of silicone-based scar treatments.
Sometimes, surgery can improve the appearance of scars. Surgery 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
Be aware that having surgery on your scar will leave a new scar that will take up to two years to improve in appearance. If surgery is used to treat a hypertrophic scar, there is a risk that the scarring may be worse after the surgery.
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 the surgery. Some plastic surgeons also add other treatments, such as X-ray therapy and oral antibiotics to try and minimise recurrence of a keloid that has been surgically treated. You can talk to your surgeon about this.
For some pitted scars, laser surgery (laser re-surfacing) is used. This involves using a laser to remove the top layers of skin, stimulating collagen production in the deeper layers to try to make the scar flatter.
The aim of pressure dressings is to flatten and soften scars. They are most often used for large burn scars or after some skin grafts.
Pressure dressings are usually made from a stretchy, elastic material. They are worn over the scar 24 hours a day, for around six to12 months. They can also be used in combination with silicone gel sheeting to improve the appearance of scars over a long period of time.
Pressure dressings are usually used under specialist supervision.
Cosmetic camouflage (make-up) can help cover up scars and can be particularly useful for facial scars. Some are waterproof and can stay in place 2-3 days.
Camouflage make-up that is specially designed for covering up scars is available over the counter at pharmacies. Alternatively ask your doctor for advice.
Please note that camouflage colour testing (to get a good colour match for your skin type) can be a lengthy process, sometimes taking over an hour, and needs to be performed by somebody who is qualified.
Laser or light therapy (pulses of light) can reduce the redness in a scar by targeting the blood vessels in the excess scar tissue.
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.