treatyourscars They are typically larger than the initial injury, are thicker or lumpier, and stand taller than the rest of your skin. The key visible difference between hypertrophic and keloid scars is the extent to which scars extend around the original wound. Clinicians define hypertrophic scars as scars that do not extend past the boundaries of the original wound, whereas keloid scars are scars that extend to surrounding normal skin.
Although the cause is not completely understood, an abnormal buildup of excess collagen and a reduction of elastin leads to hypertrophic scars. Sometimes, flat scars are hypertrophic, or thickened, but limited to the edges of the original wound. When the skin is injured, fibrous tissue called scar tissue forms around the wound in order to repair and protect the wound. Scar tissue may form as a result of injuries to or skin lesions caused by accident, inflammation, burns, and surgical incisions.
Keloids are raised, lumpy, hard, or rubbery scars resulting from abnormal healing responses to injuries to the skin. Keloids develop because the body over-protects itself after a physical injury, surgery, or injury to the skin. Keloids are benign fibrous growth that occurs within the scar tissue of susceptible individuals, extending past the boundaries of the initial injury, that usually does not regress spontaneously, and that often tends to return following excision. It is a result of uneven wound healing following insults to the skin (trauma, inflammation, surgery, burns, etc.
Keloid can develop after any type of skin injury, such as burns, injury, surgery, puncture, pimple, or vaccinations…but not every such injury results in the development of a keloid scar, even in susceptible individuals. A keloid scar may develop following a very small amount of skin injury, like an acne smear or piercing, and it may extend outside of the initial skin injury site. While most people never form keloids, others develop them after injuries, burns, insect bites, and minor acne spots.
If someone develops a keloidal scar in one area of their body, the skin can still heal normally in other areas. Treatment can help if the keloid scar causes discomfort or interferes with movement (if it covers a joint or a large area, for example). Your healthcare provider will likely initially suggest less-invasive treatments, such as silicone pads, compression dressings, or injections, particularly if your keloid scar is a fairly recent one.
There is a risk that laser treatments may worsen your keloid, by causing more scarring and redness. Laser treatment may improve scar color, and height of scars, decrease the tension on the skin over the scars, and enhance pain and itching. Radiation therapy is one of the most popular adjunct therapies for HTS, and the incorporation of laser beams, as well as light therapies, improves patient compliance and clinicians’ ability to decrease the size of the hypertrophic scar and the keloid, and there is very little likelihood that it will return following surgical treatment or excision.
While hypertrophic scars and keloids develop in burned areas, they do not ever develop in areas that have been frozen. Causes indicate that the Keloidal scars and hypertrophic scars are caused by damage to the reticular dermis and subsequent aberrant wound healing within it. Furthermore, the upregulation of proinflammatory factors in pathological scars suggests that, instead of being cutaneous tumors, keloidal and hypertrophic scars are inflammatory disorders of the skin, particularly, inflammatory disorders of the reticular dermis. As a result, reticular layers in both keloids and hypertrophic scars harbor inflammatory cells, increased numbers of fibroblasts recently formed blood vessels, and collagen deposits.
As described in textbooks, vertically directed blood vessels, collagen nodules, and fibroblasts are characteristic of keloids. In our clinical experience, we found that applying high-pressure, local hormone injections at the edges of the keloids caused injections to diffuse laterally across the skin within the scar, suggesting channeling. In fissures caused by contraction, blood vessels and red blood cells are visible, suggesting keloids contain granulations and vascular components.
In addition, vascular components are seen interwoven within the pathological structures of hypertrophic scars. Outer features of typical keloids include luminous red hyperplasia with numerous vessels, suggesting the importance of vascular components in scar formation processes and prompting the consideration of the role of inflammation in granular hyperplasia development. These features indicate that keloids develop in stages according to their natural history, and that, with hypertrophic scars, on which we generally focus, proliferation or atrophy is just one part of that natural history.
In a clinical setting, we observed a patient who developed a left-breast keloid arising from septic mastitis, in which it was in a stable stage for about thirty years.
For instance, mast cell numbers are greatly increased in the keloid suggesting the association of mast cells with abnormal scar formation. Some authors have suggested that the excess scar formation in keloids could result from decreased apoptosis in the fibroblasts, possibly leading to the balance between collagen synthesis and degradation.
TGF-b is overproduced in keloid tissues, therefore, the excessive collagen present in the keloid scars could result from the overexpression of TGF-b, as well as decreased collagen degradation. The late maturity stage of wound healing could be involved in the formation of keloid scars, because of an imbalance between collagen synthesis and degradation. The exact reasons why wound healing occasionally leads to the formation of keloid scars are being investigated, but are still unclear. In response to injuries, cells in your skin – called fibroblasts – make excess collagen, leading to keloid formation.
Abstract Keloids and hypertrophic scars are caused by injuries and cutaneous irritations, including injury, insect bites, burns, surgery, vaccination, piercing, acne, folliculitis, chicken pox, and herpes zoster infections. The differences between hypertrophic scars and keloids are in the prognosis, wherein the former develops within the initial boundaries of a wound and is susceptible to regressing with time, while the latter grows unrestricted and rarely regresses.
