Keloid scars: what they are, causes and treatment

The NHS describes a keloid scar as a raised scar that stays on the skin after a wound has healed. It usually appears a few weeks to years after you damage or injure your skin, such as after a cut, burn or acne. It usually grows for months or years and becomes bigger than the original wound. While it is growing it may feel itchy or painful, which usually stops once it has finished growing.

It is caused by the scar tissue response going on too long. The NHS says it can happen if you have too much of a substance called collagen in your skin, and after any sort of injury or damage to the skin such as a cut, burn, surgery, acne or a body piercing.

The NHS scars page sets out the main types of scar and how they behave. The key distinction is that a keloid grows larger than the original wound and does not usually flatten or fade without treatment, whereas a hypertrophic scar stays within the boundary of the wound and usually fades and flattens over time.

The NHS says you cannot get rid of a keloid scar, but there are treatments that can help improve how it looks and reduce irritation. Treatments may include steroid injections or cream, silicone dressings or gels, cryotherapy (a treatment to freeze the keloid scar) and laser therapy.

The NHS says getting treatment early may help stop the keloid scar growing, and that surgery to remove it is not usually recommended because it is likely to grow back bigger. A GP can recommend treatments, and if a scar is more severe or bothering you, a GP may refer you to a specialist.

For all scars the NHS advises massaging with a water-based cream once the wound is fully healed, keeping the scar covered or using sunscreen of SPF 30 or more for at least a year, and asking a pharmacist about silicone dressings or gels. Skin camouflage creams and powders can cover a scar, and a GP can refer you for an appointment to get them. A GP can refer for talking therapy if a scar is affecting your mental health.

The NHS says you are more likely to get a keloid scar if you are of south Asian, Chinese, African Caribbean or Black African origin, are aged 10 to 30, are pregnant or have had a keloid scar before. Keloids can occur after any sort of injury or damage to the skin.

You cannot prevent keloid scars, but the NHS says if you are more likely to get them it is recommended to avoid tattoos and piercings, and to get early treatment for acne to reduce the risk of scarring.

The NHS says keloids can occur on any part of the body, but are most common on the chest, shoulders, chin, neck, lower legs and ears. They are usually raised, hard, smooth and shiny, and range from skin colour through pink, red, purple and brown to darker than the surrounding skin.

A growing keloid may feel itchy or painful, and if it is on or near a joint, the joint can be uncomfortable or difficult to move.

The NHS says to see a GP if you think you have a keloid scar and it is bothering you. For any scar, ask for an urgent GP appointment or call NHS 111 if the scar is swollen or painful, feels warm to the touch or has pus coming out of it.

On the NHS, a GP can recommend first-line treatments such as silicone and steroid treatment and refer you to a dermatologist or plastic surgery service for resistant or large keloids. Some treatments, such as laser, may not be funded locally for cosmetic reasons.

Private dermatology and aesthetic clinics offer injections, cryotherapy and laser. Because keloids often return after surgery alone, ask any provider what they would do to reduce the risk of regrowth and how many keloids they treat.