What is a keloid?
Keloids can be considered to be "scars that don't know when to stop." 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. Unlike scars, keloids do not subside over time.
What is the difference between a keloid and a hypertrophic scar?
After the skin is injured, the healing process usually leaves a flat scar. Sometimes the scar is hypertrophic, or thickened, but confined to the margin of the wound. Hypertrophic scars tend to be redder and may subside by themselves (a process which can take one year or more). Treatment such as injections of cortisone (steroids) can speed this process.
Keloids, by contrast, may start some time after the injury and extend beyond the wound site. This tendency to migrate into surrounding areas that weren't injured to begin with distinguishes keloids from hypertrophic scars. Keloids typically appear following surgery or injury, but they can also appear spontaneously or as a result of some slight inflammation, such as an acne pimple on the chest (even one that wasn't scratched or otherwise irritated). Other minor injuries that can trigger keloids are burns and piercings.
What are the signs and symptoms of keloids?
Keloids are raised and look shiny and dome-shaped, ranging in color from pink to red. Some keloids become quite large and unsightly. Aside from causing potential cosmetic problems, these exuberant scars tend to be itchy, tender, or even painful to the touch.
What is the cause of keloids?
Doctors do not understand exactly why keloids form in certain people or situations and not in others. Changes in the cellular signals that control growth and proliferation may be related to the process of keloid formation, but these changes have not yet been characterized scientifically.
Which people are most susceptible to keloids?
Keloids are equally common in women and men, although at least in times past more women developed them because of a greater degree of earlobe and body piercing among women. Keloids are less common in children and the elderly. Although people with darker skin are more likely to develop them, keloids can occur in people of all skin types. In some cases, the tendency to form keloids seems to run in families.
In which area of the body are keloids most likely to appear?
Keloids develop most often on the chest, back, shoulders, and earlobes. They rarely develop on the face (with the exception of the jawline).
Keloids and piercing
Keloids can develop following the minor injuries that occur with body piercing. Since doctors do not understand the precise reasons why some people are more prone to developing keloids, it is impossible to predict whether piercing will lead to keloid formation. Although there are some families which seem prone to forming keloids, for the most part, it's impossible to tell who will develop a keloid. One person might, for instance, develop a keloid in one earlobe after piercing and not in the other. It makes sense, however, for someone who has formed one keloid to avoid any elective surgery or piercing, especially in body areas prone to scarring.
Is keloid prevention possible?
The best way to deal with a keloid is not to get one. A person who has had a keloid should not undergo elective skin surgeries or procedures such as piercing. When it comes to keloids, prevention is crucial, because current treatments are often not completely successful and may not work at all.
Is keloid removal necessary? What are the treatments for keloids?
The methods now available to treat keloids are:
- Cortisone injections (intralesional steroids): These are safe and not very painful. Injections are usually given once per month until the maximum benefit is obtained. Injections are safe (very little steroid gets into the bloodstream) and usually help flatten keloids; however, steroid injections can also make the flattened keloid redder by stimulating the formation of more superficial blood vessels. (These can be treated using a laser; see below.) The keloid may look better after treatment than it looked to start with, but even the best results leave a mark that looks and feels quite different from the surrounding skin.
- Surgery: This is risky, because cutting a keloid can trigger the formation of a similar or even larger keloid. Some surgeons achieve success by injecting steroids or applying pressure dressings to the wound site after cutting away the keloid. Radiation after surgical excision has also been used.
- Laser: The pulsed-dye laser can be effective at flattening keloids and making them look less red. Treatment is safe and not very painful, but several treatment sessions may be needed. These may be costly, since such treatments are not generally covered by insurance plans.
- Silicone sheets: This involves wearing a sheet of silicone gel on the affected area for several hours a day for weeks or months, which is hard to sustain. Results are variable. Some doctors claim similar success with compression dressings made from materials other than silicone.
- Cryotherapy: Freezing keloids with liquid nitrogen may flatten them but often darkens the site of treatment.
- Interferon: Interferons are proteins produced by the body's immune systems that help fight off viruses, bacteria, and other challenges. In recent studies, injections of interferon have shown promise in reducing the size of keloids, though it's not yet certain whether that effect will be lasting. Current research is underway using a variant of this method, applying topical imiquimod (Aldara), which stimulates the body to produce interferon.
- Fluorouracil: Injections of this chemotherapy agent, alone or together with steroids, have been used as well for treatment of keloids.
- Radiation: Some doctors have reported safe and effective use of radiation to treat keloids.
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