Author: A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 1997. Updated September 2014.
A keloid scar is a firm, smooth, hard growth due to spontaneous scar formation. It can arise soon after an injury, or develop months later. Keloids may be uncomfortable or itchy and extend well beyond the original wound. They may form on any part of the body, although the upper chest and shoulders are especially prone to them.
The precise reason that wound healing sometimes leads to keloid formation is under investigation but is not yet clear.
While most people never form keloids, others develop them after minor injuries, burns, insect bites and acne spots. Dark skinned people form keloids more easily than Caucasians.
A keloid is harmless to general health and does not change into skin cancer.
As wounds heal, scar tissue forms, which at first is often red and somewhat prominent. Over several months, a scar usually becomes flat and pale. If there is a lot of tension on a healing wound, the healing area is rather thicker than usual. This is known as a hypertrophic scar. A hypertrophic scar is limited to the damaged skin.
A hypertrophic scar generally settles in time or with treatment, but a keloid may persist and prove resistant to treatment. The following measures are helpful in at least some patients.
Scar dressings should be worn for 12–24 hours per day, for at least 8 to 12 weeks, and perhaps for much longer.
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