Keloids

What is a keloid?

A keloid is a scar that keeps growing beyond the size of the original wound, forming a raised, thickened area of skin. It happens when your skin produces too much collagen while healing, and unlike most scars, it won't fade or flatten on its own.

Symptoms of a keloid

A keloid usually appears a few weeks to years after a skin injury and can then keep growing for months or years. Symptoms include:

• raised, hard, smooth and shiny skin, which may be skin-coloured, pink, red, purple, brown, or darker than the skin around it
• itching, a prickly feeling, or soreness while it's growing, which usually settles once growth stops
• restricted movement or discomfort if the keloid forms on or near a joint
• more than one keloid, particularly after acne or chickenpox, though most people only develop one or two.

Rarely, a keloid can remain tender or painful even after it stops growing.

Causes of keloids and who is at risk

Keloids can develop after almost any injury or damage to your skin, such as a cut, burn, surgery, acne, or a body piercing; some appear with no obvious cause at all. It isn't fully understood why, but it happens when your skin produces too much collagen, the protein that gives skin its structure, while a wound is healing. You're more likely to develop a keloid if you:

• are of south Asian, Chinese, African Caribbean or Black African origin
• are aged between 10 and 30
• are pregnant
• have had a keloid before
• have a family history of keloids.

Keloids most often form on the upper chest, breastbone, shoulders, chin, neck, lower legs and earlobes, especially after burns, infected wounds, or wounds under tension while healing.

Are there different types of keloids?

Keloids aren't divided into distinct types, but they're often confused with a similar-looking scar called a hypertrophic scar. The two are different:

• a hypertrophic scar stays within the boundary of the original wound, tends to appear within 1–2 months of the injury, and usually fades and flattens on its own within 12–24 months
• a keloid spreads beyond the original wound, can take a year or longer to appear, and doesn't fade over time without treatment.

How keloids are diagnosed

Your doctor can usually diagnose a keloid just by examining your skin, so no tests are needed. If there's any uncertainty, they may take a small skin sample, called a biopsy, under local anaesthetic to examine under a microscope.

How keloids are treated

Non-surgical treatment

There's no cure for keloids, and no single treatment works better than another for everyone. Even after successful treatment, they often regrow in the same place. Options include:

• steroid injections directly into the keloid, the most common treatment, usually repeated monthly for 4–6 months. This can thin, weaken or lighten the skin, and up to 50% of keloids regrow afterwards
• steroid cream or steroid-containing tape, available on prescription
• silicone dressings or gels, which you can buy without a prescription and which may reduce thickness and lighten the keloid if used for several months
• compression with bandages, clips or splints, particularly for keloids on the earlobe or torso
• cryotherapy, which freezes the keloid and can be used alone or alongside other treatments, though it can cause loss of skin colour
• laser therapy, which can help, especially combined with steroid injections.

Other treatments, such as botulinum toxin (botox) injections, 5-fluorouracil injections, or photodynamic therapy, are used in some specialist clinics, though they aren't routinely available and need further research.

Surgical treatment

Surgery to remove a keloid isn't usually recommended on its own, since it can create a larger wound and the keloid is likely to grow back bigger. If surgery is carried out, the risk of regrowth may be reduced by combining it with compression dressings or steroid injections afterwards. Radiotherapy can also be given after surgical removal, and this is more effective at preventing keloids from returning than surgery alone. It's used sparingly, though, since it carries a small risk of causing skin cancer from the radiation exposure.

When to see a doctor

See a GP if you think you have a keloid scar and it's bothering you. They can recommend treatment to improve how it looks, and treating it early may help stop it growing further.