Keloid Scars

A keloid scar is one in which there is overgrowth of dense fibrous tissue. This usually develops after the injury has healed. It extends beyond the borders of the original wound. It does not normally regress spontaneously, and it will usually recur after excision. This contrasts with hypertrophic scars, which stay within the borders of the original wound.

The term cheloide was coined by Alibert in 1806,¹ from the Greek chele, meaning crab's claw - to describe the lateral growth of tissue into unaffected skin.

Keloid scars are more common in people with darker skins, especially African-American races.
The peak age is 10-30 years, and keloids are less common at the extremes of age.
There may be a family history of tendency to develop keloids.

The cause is unknown, although there are various theories.²

History

• Symptoms: usually cosmetic, although the scar may be tender, painful, itch or produce a burning sensation.
• There is usually a history of trauma that may be accidental, surgical or cosmetic.
• Sites for keloid formation: the most common areas are sternum, shoulder, earlobe and cheek.
• Burn scars or infected lesions, including acne, are more likely to form keloids.⁴

Clinical features

• The scar has grown beyond the original line of trauma and may be raised and irregular.
• The texture is rubbery.
• It is red in the early stages, but becomes brown or pale with age.
• There are no hair follicles or sweat glands within the scar.
• Keloids over a joint can contract and restrict movement.
• Clinical course: The natural history is variable:
  • Most lesions grow for weeks - months, but growth can continue for years.
  • Growth is usually slow, but some keloids can enlarge rapidly over months.
  • When they stop growing, they remain stable or regress slightly.

Assessment

• The diagnosis is made clinically; investigations are not required.
• Assess the patient’s concerns and the impact of the scar(s) on their life.
• Check if the scar reduces mobility, e.g. near a joint.

Hypertrophic scars are also red and prominent, but do not extend beyond the wound border. Hypertrophic scars usually appear within a month of the injury, grow for several months and then regress; whereas keloids may appear later and continue growing for longer.

Keloid scars are difficult to treat. There are various options. Reviews suggest that combinations of treatments are probably the most effective.²

Local steroids^2,3

Intralesional steroid injections (with triamcinolone) are a mainstay of treatment and prevention - reviews suggest that it improves the majority of scars.

• Injections are given every 2-6 weeks until improvement.
• Side-effects: Pigment changes, telangiectasia and subcutaneous atrophy (which may resolve).

Steroid-impregnated tape applied for 12 hours/day may flatten keloids.⁴

Pressure or occlusive dressings

These are used both for treatment and prevention, with minimal adverse effects provided they are practical and acceptable to the patient. They must be used for 12-24 hours daily for several weeks or longer.⁵

• Silicone gel^2,6 - this is applied as topical gel or a gel-impregnated sheet.
• Compression earrings - are used after excision of earlobe keloids, and give good rates of recurrence-free healing; they should be worn 24 hours/day.²
• Self-adhesive polyurethane scar reduction patches are also suggested.⁵
• Other pressure dressings may be used.⁴

Surgery³

Surgical excision on its own has a very high recurrence rate, and the recurring scar may even be larger than the original. Results can be improved by:

• Meticulous surgical technique
• Additional treatments such as intralesional steroids, occlusive or pressure dressings or radiotherapy.

Radiotherapy

Radiotherapy has been used, both alone and after surgery, with variable results.³ As it is a carcinogen, safety concerns limit its use.⁷ However, some argue that it should be used more often at sites where radiation to visceral structures can be avoided.²

Cryotherapy

Cryotherapy has been used alone and combined with other treatments. Reported results vary.

• Cryotherapy may stop early stage keloids from growing.⁴
• It may be effective in combination with intralesional steroid.⁸
• Hypopigmentation is a side-effect.

Other possible treatments²

Laser treatment:³

• Argon and carbon dioxide laser are probably not effective.
• Pulsed dye lasers and Nd;YAG lasers are reported to give encouraging results, with few adverse effects. However, pulsed dye lasers are less effective on dark skin.²
• Laser treatment may reduce the redness of keloids without shrinking them.⁴

Interferon therapy:

• Treatment with interferon-alpha has been studied recently: on its own, it does not seem effective,⁹ but interferon combined with intralesional steroid may be beneficial.¹⁰

5-fluorouracil:³

• May be beneficial when used alone or in combination with other treatments.
• Possible side-effects are pain, hypopigmentation and tissue sloughing.

Bleomycin:³

• This cytotoxic agent can be given locally as intralesional injections, and improved scars in one small study. Side-effects were hyperpigmentation and dermal atrophy.

Retinoids:

• Topical or intralesional retinoids have been used in clinical trials and produced some improvements.²

Pharmacological treatment: various agents are being investigated.³

For people at high risk of with a history of keloids:

• Avoid body piercing, tattoos and unnecessary incisions such as cosmetic surgery - particularly to skin sites more prone to keloid formation (see above).
• Treat acne thoroughly to reduce lesions and potential for scarring.
• If surgery is required, it may be combined with dressings, intralesional steroids or other treatments (above) to reduce the likelihood or size of keloid scarring. Care with surgical technique is important.