Apologies for adding another post so suddenly, but I was just wondering why scars heal in differnet ways. For example, some scars I have are raised while others are leveled with my skin but white or discolored instead. I have also heard of things like keloids where they turn into big masses. Is there a reason for how the body produces scar tissue in these different ways?
In: Biology
Soooo this is actually a very great question! There are many factors such as the size of the laceration, the age of the skin that was lacerated, if it was closed by primary intention (suturing), and frankly how the individual closed the wound. Additionally wound healing is an immune driven process and everyone’s immune system is different/more sensitive.
First let’s start with general wound healing of a simple cut. Once the skin is breached your immune system is triggered, which essentially starts the healing process. Your body is programmed to respond non-specifically to physical insults the same way it responds to an infection. This means immune mediators are released which recruits fibroblasts to start laying down type 3 collagen (semi)haphazardly and skin cells start to migrate over the wound. The collagen serves as a filler This form of collagen is eventually metabolized to type 1 collagen. Eventually skin contracts and you get the typical hypertrophic scar. The scar is obvious (in most cases) because newer skin and connective tissue was laid down and not neatly arranged like unlacerated skin. Additionally, typically healed/fibrous tissue is never the same as the original stuff so you can think of it as a crude replacement for what was lost. The best example I can think of is if you’ve ever seen a pothole or cracked cement patched. Even though you’ve filled the holes and cracks, you can always tell where the patchy is bc it’s a different age a consistency than when a road was first made.
Keloids are essentially the overproduction of the collagen associated with wound healing. The collagen gets made without much regulation and in excess so it builds up. In medicine we are taught there are genetic predispositions to keloids, individuals with darker skin/complexion are more likely to develop them, and folks in their teens-twenties are higher risk (the latter point always made sense to me as your immune system is really at its peak in your 20’s).
There are A LOT of factors that contribute to proper wound healing. Age is a big factor. Our skin thins as we age and our immune system is less effective, so scars can tend to contract less and can look more noticeable. Nutrition status is also very important for healing and scar appearance! Copper, magnesium, and vitamin C are vastly important for wound healing, and if you are lacking these your skin may not regenerate as quickly or of the same quality.
Another important point is where the wound is. Wounds on the lips require special approaches to ensure they are closed properly without losing function or too much form due to the complicated architecture of the skin. With more varying directions of skin, a scar may heal more unevenly or be noticeable. A laceration on your arm, in comparison, has less complexity may “fill in” more seamlessly.
Now with all this in mind, essentially this makes the case for suturing wounds because the intent is to close the wound but also bring the edges closer together so that the skin is positioned optimally for this process. This allows skin to be joined at both ends at a point, so when collagen is made and the wound contracts it’s a more seamless fit. Additionally there are A LOT of suturing techniques that can be used based on the type of laceration and condition of the skin. Basically, this is why plastic surgeons can make a lot of money (and people are willing to pay them a kings ransom) for suturing someone’s lip.
All in all – wound healing is actually an amazing process and the human body is really capable of so much. Hope this helps!
Latest Answers