Definition of keloid
Keloids are cicatricial lesions that grow beyond the border of a skin lesion: starting therefore from an abrasion or from a wound, the keloids develop a much wider and extended scar with respect to the damage of origin.
- Let us briefly recall that the granular tissue, richly vascularized, consists of fibroblasts, myofibroblasts, inflammatory cells and ECM (extracellular matrix).
The presence of one or more keloids on the skin is often observed in subjects between the ages of 10 and 30, especially among Hispanics, African Americans and Asians. Despite what has been said, keloids can still appear in subjects of every race and age.
Curiosity
The curious term "keloid" derives from a Greek word χηλή (chele) which, in Italian, literally means "similar to the claws of the crab": in fact, the solid consistency and the spongy appearance of the keloid form a sort of relief drawing on the skin, similar to the claws of a crab.
Causes
We have seen that keloids are extensive and abnormal scars that can originate from an initial skin trauma. The main defendants are undoubtedly ear piercings, very severe acne lesions, burns and surgical wounds (characteristic examples are the keloids that arise at a cesarean section). Sometimes, some keloids can be observed even in areas subjected to vaccination or in locations where small scars from chicken pox have remained.
Did you know that ...
The term "keloidosis" is used in place of "keloid" when these cicatricial lesions are very numerous (eg keloid scars caused by severe acne) or recurrent.
But why and how is a keloid formed?
These cicatricial lesions are mainly due to an excessive and unregulated proliferation of fibroblasts in the deep dermis, which produce abnormal amounts of collagen: the overproduction of collagen, in turn, gives a solid consistency to the scar.
Risk factors
With the same lesions and traumas, some subjects develop keloids more rapidly (or more clearly). Starting from this assumption, it is believed that keloids can be influenced by some risk factors, listed below:
- Severe acne
- Alteration of the subject's immune function
- Abnormal response to a skin lesion
- Deficiency or excess of melanotropic hormone, used for the synthesis and distribution of melanin granules in melanocytes
- Dysfunctions in the extracellular matrix that controls growth factor activity
- Familiarity
- Folliculitis of the beard and neck
- Too small blood vessels. By blocking themselves, the small blood canals fail to exchange oxygen effectively; consequently, following a traumatic injury to the skin, the formation of keloids is encouraged.
Signs and symptoms
The greatest damage related to the presence of keloids is given by their appearance: in fact, many patients resort to a pharmacological / alternative treatment to cancel the lesions worried that they may more or less clearly disfigure their image. In addition to being patently unsightly, keloids can cause discomfort, itching, tenderness to the touch or hypersensitivity of the skin where they develop.
Most keloid lesions grow irregularly for weeks or months; in some cases, growth can continue for many years. At the end of development, the keloid stabilizes without regressing spontaneously: the natural disappearance of these lesions is a rather unlikely event.
How they present themselves
At the initial stage, the keloid appears as a simple scar in relief: the lesion has a smooth, glabrous (hairless) and translucent surface. In this phase, the keloid lesions have an intense red color because they are extremely vascularized.
Subsequently, the scar begins to extend and to reveal itself, clearly overcoming the limits of the initial lesion: now, the keloid shows a rosy color and its consistency becomes increasingly thick and rubbery.
On the surface, the keloid has no hair follicles or sweat glands.
Although keloids can appear in any skin area affected by bruises or wounds, some areas of the body appear to be more sensitive. In fact, keloid lesions are observed more often in the deltoid region (shoulder), at the level of the sternum and in the upper part of the back. Also the ear lobes and the back of the neck are other rather common targets of keloids.
