Keloids and hypertrophic scars
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. They can arise soon after the injury, or develop months' later.
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 may form on any part of the body, although the upper chest and shoulders are especially prone to them. Dark skinned people form keloids more easily than Caucasians.
Keloid scars are usually just a cosmetic problem. They never become malignant.
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 hypertrophic and keloid scars
Hypertrophic scars generally settle in time but keloids may prove resistant to treatment. The following measures are helpful.
Dressings should be worn for 12 to 24 hours per day, for at least 8 to 12 weeks, and perhaps for much longer.
- Moisturising oils
- Polyurethane or silicone scar reduction patches
- Silicone gel
- Pressure dressings
- Surgical excision (but may result in a second 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