Scars can reduce movement, especially if they occur near joints.
Scars are caused by the body’s inability to regenerate the complex connective tissue in our skin after injury.
During my years as a research scientist, I became very familiar with the sight of scars. From the small one on my finger after an incident with a knife to the cluster on my knee following a skiing accident, I, like many people, have a collection of scars with accompanying anecdotes.
Some scars – especially those caused by accidents, military trauma, or burn and scald injuries – can cause a lifetime of physical and psychological burden.
But why are our bodies unable to heal our skin after an injury? And is modern medicine going to solve this problem?
Skin: The two-faced player
Our skin has two layers. The outer layer, or the epidermis, is the barrier to the environment. It protects us from infection and the sun’s ultraviolet (UV) rays, and it keeps our skin waterproof.
The epidermis comprises several layers of cells, which are naturally very good at regenerating. As such, superficial injuries such as scrapes tend not to scar.
Underneath the epidermis is the dermis, or the deeper layer of the skin. Here, a more complex arrangement of connective tissue molecules is responsible for our skin’s strength and elasticity.
A section of skin under the microscope shows the layers of cells in the epidermis (top), and the collagen fibers in the dermis (pink). These irregular lines and shapes form the so-called basket weave pattern.
These molecules, which are mostly collagens, are arranged in a pattern that scientists call basket weave. Under the microscope, it looks like an irregular arrangement of long collagen tendrils interwoven with other small molecules, crisscrossing the entire dermis.
Now, there is the rub; the basket weave pattern is established when we develop in our mother’s womb. But once we are born, our bodies do not have the ability to make this pattern again.
Instead, when our dermis is damaged, the connective tissue molecules are arranged in parallel stacks, filling the wound, and causing a scar.
This spells bad news for our skin. While scars continue to evolve over time, the skin will never be as strong and elastic again. But surely, modern science and medicine can fix this? Unfortunately not.
The elusive secret to regeneration
The problem is that nobody really understands quite why the cells that make connective tissue are unable to regenerate the basket weave pattern.
There is a small window of opportunity during embryonic development when we heal without scarring. Scientists are studying this process, in the hope of being able to replicate it in patients with severe injuries.
Despite many scientific advances, there is no definitive way of preventing or treating scars yet. But there are things that doctors and patients can do to reduce the extent of scar development.
- wearing tight bandages or pressure garments
- massaging the scar to help break down the rigid parallel stacks of connective tissue
- protecting the scar from UV radiation
- silicon sheets to keep skin hydrated and slow down collagen buildup
Despite the plethora of products on the market – particularly creams – that claim to reduce scarring, there is no scientific evidence at the moment to support these assertions.
While we may not be able to prevent or cure scars yet, scientists are getting closer to developing treatments that will reduce the damage that scars can cause.