diease

Keloid


Keloid overview and Definition

Keloids are firm, pink to red, itchy, irritated bumps that tend to gradually enlarge and appear at the site of previous skin damage.Keloids develop as a consequence of abnormal scar formation.People with darker skin are typically more predisposed to develop keloids.Simply cutting out a keloid is likely to result in an even larger keloid developing at the excision site. A keloid, sometimes referred to as a keloid scar, is a tough heaped-up scar that rises quite abruptly above the rest of the skin. It usually has a smooth top and a pink or purple color. Keloids are irregularly shaped and tend to enlarge progressively.


Pathophysiology

Keloids are dermal fibrotic lesions that are the variations of the normal wound healing. They usually occur during the healing of the deep skin  wound. The keloid scar and hypertrophic both shares the wide spectrum of fibroproliferative disorders. These abnormal scars result from the loss of control mechanisms that normally regulate the fine balance between the tissue damage and the regeneration.

The excessive proliferation of normal tissue in healing process results in both hypertrophic scars and keloid scars. The production of the extracellulae matrix proteins, collagen, elastin and proteoglycans is due to a prolonged inflammatory process in the wound. These hypertrophic scars are raised, erythematous, fibrotic lesions that are confined only to the wound. The main concentration area of the keloid scar is the body area that are subjected to high skin tension. Wounds on the anterior, chest, shoulders, flexor surfaces of the extremities and anterior neck and wounds that crosses the skin tension lines that results in the abnormal scar formation.

The most important risk factor for the development of abnormal scars such as keloids is a wound healing by secondary intention, especially if healing time is greater than 3 weeks. Wounds subjected to a prolonged inflammation, whether due to a foreign body, infection, burn, or inadequate wound closure, are at risk of abnormal scar formation. Areas of chronic inflammation, such as an earring site or a site of repeated trauma, are also more likely to develop keloids. Occasionally, spontaneous keloids occur without a history of trauma.

 

When the skin undergoes the initial injury the formation of the wound clot occurs the balance between the granulation tissue degradation and biosynthesis becomes essential to adequate healing process.  Keloids shows increase in the blood vessel density that is the thickening of the epidermal layer and increase in the mucinous ground substances. The alpha smooth muscle actin filaments, myofibroblast which are important for contractile situations.

The collagen fibrils in keloids are more irregular, abnormally thick, and have unidirectional fibers arranged in a highly stressed orientation.  Biochemical differences in collagen content in normal hypertrophic scars and keloids have been examined in numerous studies. Collagenase activity, ie, prolyl hydroxylase, has been found to be 14 times greater in keloids than in both hypertrophic scars and normal scars. Collagen synthesis in keloids is 3 times greater than in hypertrophic scars and 20 times greater than in normal scars. Type III collagen, chondroitin 4-sulfate, and glycosaminoglycan content are higher in keloids than in both hypertrophic and normal scars. Collagen cross-linking is greater in normal scars, while keloids have immature cross-links that do not form normal scar stability.

The increased numbers of fibroblasts, recruited to the site of tissue damage, synthesize an overabundance of fibronectin, and receptor expression is increased in keloids. Mast cell population within keloid scars is also increased, and, subsequently, histamine production increases.


Clinical signs & symptoms

raised, pink elevations

Feel soft, rubbery or doughery

Itchiness

Appears slowly

The main areas include:

  • Ears

  • Neck

  • Shoulders

  • Chest

  • Back

 


Differential Diagnosis

If needed the physician might opt for the Skin Biopsy.


Prevention

After ear boring check if thickening of the skin is present , it might result in the keloid formation in the latter stages.

Use sunscreen lotions

Before doing the body piercing, tattooing and other cosmetic procedure for the skin try to test the healing of the skin.