What is a keloid scar?
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 may be much larger than 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 a skin cancer.
What is a hypertrophic scar?
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.
Treatment of a hypertrophic or keloid scar
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.
- Emollients (creams and oils)
- Polyurethane or silicone scar reduction patches
- Silicone gel
- Oral or topical tranilast (an inhibitor of collagen synthesis)
- Pressure dressings
- Surgical excision (but in keloids, excision may result in a new keloid even larger than the original one)
- Intralesional corticosteroid injection, repeated every few weeks
- Superficial X-ray treatment soon after surgery.
- Pulsed dye laser
- Skin needling
Scar dressings should be worn for 12 to 24 hours per day, for at least 8 to 12 weeks, and perhaps for much longer.