What is a Scar?
A scar is a mark left on the skin after the body naturally repairs damage. Scars can be fine and almost invisible or be an overgrowth of skin that is clearly seen.
About a hundred million people annually in the developed world will get a scar. Whilst some will not cause any major distress others are considered disfiguring and ugly to look at.
They can result in severe itching, pain and tenderness leading to anxiety, depression, sleep disturbances and interference with quality of life. (1)
Causes
Skin is the one of the largest organs in our body, weighing up to 10 kilograms and covering up to two square meters. (2)
A scar appears on the skin as a natural outcome of repair to damage within the inner layers of skin. To better understand how this happens we will explain the three layers of our skin.
Epidermis
This outer layer of skin protects your body and helps in the production of new skin cells. It also produces melanin, a pigment which gives skin its color.
Dermis
This thicker layer of skin lies beneath the dermis which produces sweat to keep you cool and oils to lubricate the skin. It also contains hair follicles, nerves that help you feel pain and blood vessels that feed the skin.
Subcutaneous Fat
This is the bottom layer and attaches the dermis to our bones, muscles and gives the skin structure. It provides help to the nerve cells and blood vessels connecting them to the rest of the body.
Helping control body temperature and storing fat for protection are further functions of this layer. (3)
Injuries to layers beneath the epidermis can leave scars. One of the building blocks of our skin is collagen which helps repair wounds. During the healing process excess collagen is produced and this makes the skin in that area less flexible and thicker. Consequently a mark is left on the skin of which we call a scar. (4)
Here we will detail causes of damage to the skin which can result in a scar.
Wounds
Wounds can come in all shapes and sizes. You might cut yourself with a knife while preparing food or fall over and graze your knees. Wounds can also be a result of something more serious like a car accident.
The laceration to the skin damages the tissue and as it heals a scar forms.
Surgery
When a surgical procedure is performed an incision is made into the skin. Whilst this is closed with sutures or other means after surgery, a scar will be left.
Burns
Burns can be minor, caused by an iron or hot pan when cooking, alternatively if you are involved in a fire they can result in major injury. Tissue damage can also occur from burns caused by chemicals or sunlight.
There are six degrees of burns, categorized as to how deep the burn goes. First degree burns damage the epidermis and usually heal on their own quite quickly. Second degree burns penetrate into the dermis and if they cover a large area may need a skin graft.
Third degree burns injure both top layers of skin and generally need a skin graft. Fourth degree burns reach fat, fifth degree burns muscle, and sixth degree burns reach down to the bone. (5)
Damage from sunburn or minor burns might heal without scarring. More serious burns will leave a scar.
Acne
Acne can be mild or severe, from the occasional pimple or blackhead to the longer lasting multiple pus filled pimples.
The odd breakout is unlikely to scar but severe acne can damage the skin and lead to scarring. (6)
Chickenpox
This viral infection is more prevalent in children although adults can also get it. Manifesting as a mild fever it is accompanied by an extremely itchy skin rash which forms red blisters.
The blisters will usually scab and fall off, however if scratched they can become infected or leave scars. (7)
Epidermolysis Bullosa
Some skin diseases can result in scars, a group of which are called epidermolysis bullosa. These rare conditions cause blisters to appear on the skin or in other parts of the body like the mouth. They are also able to form in the esophagus, bladder and stomach.
Dependent on where the blisters appear classifies the type of condition, however blisters on the skin are the most common. (8)
Hidradenitis Suppurativa
This chronic inflammatory disease appears in areas of the body where there are apocrine glands, usually the armpits and groin. A blockage of hair follicles in these areas causes an abscess to form.
The abscess might burst and clear however infection can track under the skin causing further abscesses to appear. The resulting scars can be deep and widespread. (9)
Pregnancy and Weight Gain/Loss
Pregnancy, sudden weight changes or growth spurts in puberty are the main factors that result in stretch marks. These scars usually appear on the abdomen, thighs, buttocks or upper arms. (10)
Symptoms
Scars will vary in appearance dependent on the cause, wound size, area of the body and way they were treated. (11)
Flat Scar
This scar first looks pink or reddish in color and might be slightly raised from the surrounding skin. It can be painful and will most likely itch. Over time these scars flatten and change color, sometimes blending in with your skin.
Raised Scar (Hypertrophic)
As implied by the name, these scars are raised above the surface of the surrounding skin. They might flatten out over time but it can take from months to years before this happens.
Depressed Scar (Atrophic)
These are the types of scar you are likely to see after chicken pox or severe acne. They are sunken below the surface of the surrounding skin and might become more obvious as your skin ages.
Keloid
These large scars appear above the surface of surrounding skin and are likely to be much bigger than the original scar. They will be itchy and painful and might not appear immediately after an initial scar has healed. It could be months or years later when this scar changes form and it will not become less noticeable with time.
Contracture Scar
A contracture scar might occur after an extensive burn, it tightens and restricts movement.
Any scar that restricts movement will need treatment from a dermatologist to resolve the issue.
Stretch Marks
Stretch marks (striae) are firstly seen as pink, red or reddish brown lines on the skin which might be raised. Over time they fade and form white or silvery lines or grooves.
They form when the dermis is stretched for a period of time and it loses elasticity and breaks. The initial raised lines and color are attributable to the blood vessels showing through the skin. When they fade to white or silvery lines, this is the subcutaneous fat showing through. (12)
Diagnosis
Scars can decrease in appearance as they age and cause no lasting discomfort. However there are times when you may need to seek medical help.
Your doctor will examine the site of the scar and ascertain if it is causing pain or is itching. They will assess whether it is causing restriction of movement, especially if it is on a joint or is a contracture scar.
They will also assess the impact that scarring is having on your daily life whether physical or psychological.
Dependent on the outcome there are non invasive treatment options which might improve the appearance and function of a scar. These include oils, creams, compression therapy and hydrotherapy.
If necessary you might be referred to a plastic surgeon for more invasive treatment. These include surgery to restructure the scar, laser therapy, skin grafts, radiotherapy and various injections. (13)
FAQ
What is a scar? A scar is the mark left on the skin when the body naturally repairs damage. Scars can be fine and almost invisible or be an overgrowth of skin that can clearly be seen.
What causes a scar? A scar forms when the lower layers of skin are damaged. This can be caused by injury, burns, surgery, viral infection, skin diseases, pregnancy and sudden weight changes.
How do doctors test for scar? A scar is a result of skin trauma and will often pose no complications. However if movement is impaired or it causes psychological issues then a doctor can assess the treatment options available.
When should you go to the doctors with a scar? If a scar becomes painful, itches, grows, restricts movement or causes emotional issues you should see a doctor.
Can you prevent a scar? Whilst scars are more than likely inevitable at some point in your life, there are things you can do to improve their final appearance. Proper wound care can benefit the outcome: keep wounds clean, get stitches when you need them and keep wounds moist. (14, 15)
What can relieve a scar? We have already established scarring cannot be prevented but the application of silicone gels or creams might improve the overall outcome. This improves hydration when the scar is healing. (16)
Is a scar permanent? Unfortunately, yes it is, but there are things that can be done to improve the appearance. These include non invasive and invasive treatments.
Are there any natural remedies for scar? There are many over the counter remedies that purport to eliminate scarring. We know that is not possible, but treatments containing onion extract might assist in reducing the appearance of scars. (17)
Summary
A scar is the permanent mark left on the skin after the body naturally repairs damage and cannot be prevented.
There are many things that cause scarring and initial care of wounds can improve their final appearance.
Fortunately when a scar is painful, restricts movement or causes emotional distress there are medical interventions that can help.