A keloid is a patch of excessive scar tissue that may form following a skin injury. Occasionally scars enlarge spontaneously to form firm, smooth, hard growths called keloids. Keloids may be uncomfortable or itchy, and may be much larger than the original wound. It is not known why keloids appear. While most people never form keloids, others develop them after minor injuries, even insect bites or pimples. Keloids generally form after a skin injury heals. For unknown reasons, some people produce an excess of dense, fibrous tissue at and around the site of injury.
What are the signs and symptoms?
Keloids are thick, smooth areas of pink scar tissue. The scar tissue is raised above the level of the surrounding skin. Some keloids are itchy or tender. Keloids may form on any part of the body, although the upper chest and shoulders are especially prone. Dark skinned people form keloids more often than whites. Once keloids form they stay permanently at the same site.
What are the causes and risks of the condition?
The exact cause of keloids is unknown. They do run in families, however, and are associated with certain abnormal genes. Other risk factors for keloids include the following:
Age between 10 and 30
Type A blood
Keloids are associated with skin healing after injury. Some events associated with keloid formation include the following:
Accidental injuries, such as gunshot wounds
Piercing of body parts, such as the earlobes and abdomen
Persons who tend to develop keloids should avoid cosmetic procedures to their skin. If surgery is necessary, an injection of cortisone can be made into the skin first. This may lower the risk of developing a keloid.
How is it diagnosed?
Keloids are diagnosed by their appearance.
What are the risks to others?
Keloids may be cosmetically embarrassing. However, they cause no long-term health problems. Keloids are not contagious and pose no risk to others.
What is the treatment?
The treatment modalities available are:
Corticosteroid injection, repeated every few weeks
Cryotherapy which involves freezing the keloid with liquid nitrogen
Silicone gel dressings
Self-adhesive polyurethane scar reduction patches
Pulsed dye laser. This is a costly procedure
Surgical excision (but may result in a second keloid even larger than the original one)
Laser surgery to cut the keloid
Radiotherapy to remove the keloid
What are the side effects of the treatments?
Surgery may cause bleeding, infection, or allergic reaction to anaesthesia. Surgical removal of a keloid may cause an even larger keloid to form.
What happens after the treatment?
Keloids may continue growing for many years. Keloids do not disappear or become normal in size. Over time, however, they usually flatten and become less pink and obvious.