Did I develop a keloid or is this just a hypertrophic scar?
On Jun 12, 2013
Keypoint Tweet @CentralSkin: Exuberant skin healing leads to keloids and hypertrophic scars.
Scarring results from your body’s response to an injury. Typically, a small cut, such as a razor burn, on your finger or arm will not result in scar formation. However, a scar may be formed by your body's healing response to a large injury, or an injury that gets infected. Think of it as a tattoo that you never asked for! There is however a difference between normal scar formation and abnormal scar formation. Normal scar formation generally results in flat scars that stay within the boundaries of the original wound. Abnormal scar formation falls within two categories: hypertrophic scars and keloids.
How does the body normally respond to injury?
When a tissue is injured, blood vessels within the tissue may break and cause blood to leak out. This typically leads to the activation of platelets, which are components of your bloodstream which help the body stop the blood leakage by inducing blood clot formation. Throughout this whole process, your body’s immune cells become activated and hone in on the injured area to induce inflammation, resulting in redness. This inflammation stimulates fibroblasts, the skin cell that are responsible for producing collagen fibers. Activated fibroblasts secrete collagen fibers and begin the reparation process. Initially, scars covering the wounds are fairly weak and may be easily broken. However, in a matter of weeks to months, scars remodel and result in skin that can withstand stronger forces. During the remodeling process scars tend to lose their red color and become more skin-toned. This occurs because the tiny blood vessels which grow within an area of scar formation eventually disappear after the body no longer needs any extra circulation at the wound site.
What is the difference between keloids and hypertrophic scars?
Hypertrophic scars may be wide and uneven, but they still remain within the margins of the original injury. In contrast, keloids are an overgrowth of dense scar tissue that can grow beyond the boundaries of the original injury. Keloids may grow laterally into unaffected tissue and may form nodules of varying sizes. In susceptible individuals, keloids may form from fairly innocuous injuries such as ear piercing or tattoos. Keloids may also result from the abnormal healing response to dermatological conditions like inflammatory acne or an exuberant skin infection.
Both keloids and hypertrophic scars result from an exaggerated scar response to tissue injury. In people prone to keloid formation, there is an overabundant secretion of collagen, the fibrous component that gives your skin shape and strength. In contrast to people who heal normally, people who form keloids heal by the haphazard arrangement of collagen that results in a mass of tissue.
What do keloids look like?
Keloids are usually skin colored and are either in the shape of a round or an oblong nodule. As shown in the photograph on the right, when keloids first form they may take on red or purple hues. In addition, keloids may become inflamed and thereby also take on a reddish color. Inflamed keloids may become tender and/or itchy.
Who gets keloids?
African Americans, Hispanics, and Asians are typically the most prone to getting keloids. Caucasians rarely get keloids. In contrast, hypertrophic scars are an equal opportunity nuisance and occur in all races.
What do I need to know about treatment?
Unlike keloids, hypertrophic scars usually enlarge, reach a certain size, and eventually stabilize or regress. Untreated keloids generally tend to persist or increase in size. In fact, excision of a keloid may result in the formation of an even larger keloid at the excision site. For these reasons, the best treatment for keloids is steroid injection by your doctor. However, in instances in which the keloid is very dense, enlarged, or unresponsive to steroids, excision may be performed if it is followed up by compression dressings and repeated steroid injections.
If you are prone to develop keloids or hypertrophic scars, prevention is key. While it is difficult to prevent injuries, you can make sure to avoid skin piercing or tattooing. If you already have keloids which you would like to have treated, make an appointment with your friendly neighborhood dermatologist and discuss the possible treatment modalities with him or her.