Keloids are benign (noncancerous), fibrous skin tumours. They are most common in people with darker skin (e.g., people from West Africa or Southern India) and people usually develop them between the ages of 10 and 30. Both men and women are equally likely to have keloids.
Keloids usually occur at the site of skin damage (e.g., acne, burns, chicken pox, cuts, insect bites, piercings, surgery, tattoos, vaccinations), although they can occur spontaneously. Whether or not a keloid will form is not determined by the severity of the wound – even a minor skin abrasion can result in keloid formation.
Keloids are the result of abnormal wound healing.Normally, there is a balance between the production and the breakdown of collagen, which is a protein that makes up the fibres in the skin. With keloidal scars, the cells in the skin called fibroblasts produce excessive amounts of collagen. The collagen fibres are also thicker and wavier. This leads to the thick, raised appearance that is characteristic of keloidal scars. It is unclear what prompts this unusual healing process. Possible causes include genetic factors, skin tension, skin colour (they are more common in those with darker skin tones), and the presence of a very high number of fibroblasts in the skin.
Making the Diagnosis
Keloids can be diagnosed by your doctor or dermatologist (skin specialist). Diagnosis is based on the location and appearance of the scar, and how it progresses over time. Your doctor may do a physical exam and look at your medical and personal history to rule out any other possible diseases or conditions.
Treatment and Prevention
Currently, there is no completely effective way to treat keloids or to prevent their formation. Traditionally, surgical removal of the scars was recommended. However, 45% to 100% of people will have a recurrence of the scar if surgery is not combined with other treatment (e.g., radiation, pressure dressings). Furthermore, the new scar can actually be larger and more prominent than the original scar.
A mainstay for both treatment and prevention is the injection of steroids such as triamcinolone directly into the scar. Steroids help prevent inflammation and promote the breakdown of collagen. This helps to make scars less raised, and to decrease pain and tenderness associated with the scar.
Laser therapy is now used to treat many types of skin problems, including keloids. It is often combined with steroid injections to give the best cosmetic result.
Silicon gel dressings are a popular alternative to steroid injections, although there is only limited evidence suggesting the dressings are effective in preventing abnormal scarring in people who are at high risk of developing keloids. Other treatment options include radiation therapy and medications such as interferon*, 5-fluorouracil, and bleomycin; and radiation therapy.