Cortisone Injections for Keloid and Hypertrophic Scars

Keloid and hypertrophic scars are raised, reddish nodules that develop at the site of an injury as part of the body’s normal healing process.  After an injury or infection such as acne,  skin cells and connective tissue cells (fibroblasts) begin multiplying to repair the damage.

A normal scar is made up of 'connective tissue', gristle-like fibers deposited in the skin by the fibroblasts to hold the wound closed. In some people the fibroblasts continue to multiply even after the wound is adequately repaired, with the result that mounds of excessive scar tissue form. These are known either as keloid or hypertrophic scars.

• Keloid scars tend to grow beyond the size of the original injury which means even a small injury such as a pimple can result in a large scar. Keloids are often raised, red, firm nodules and may also be discoloured, painful and/or itchy. Keloids usually don't get better with time. They may form on any part of the body, although the upper chest, shoulders and upper back are especially prone. The inflammation associated with acne can trigger the skin to form keloid acne scars on the face.

  Approximately 10% of people are prone to keloid scarring and in some it can occur after relatively minor injuries such as insect bites and acne. Darkly pigmented people seem to be more prone to forming keloids. Men and women are equally affected.

• Hypertrophic scars look similar to keloid scarring, but tend only to grow within the boundary of the initial injury. Hypertrophic scarring is more common than keloid scarring and is also more likely to gradually improve over time. It is less likely to be painful or itchy.

• Cortisone Injections: Corticosteroid creams and injections are the most common treatment for keloid scarring. A course of cortisone injections spaced at 2-3 weekly intervals usually flattens the scar and reduces the itching and pain. Hypertrophic scars often respond completely, but keloid scars can be more difficult to treat and recurrences can occur.

  Cortisone injections are not too uncomfortable and are usually well tolerated. Local anaesthetic injections can also be used to eliminate all discomfort if required.  Cortisone injections are safe, in that very little steroid gets into the bloodstream.

  Cortisone injections must be administered cautiously to avoid over treatment. Risks of cortisone injections include too vigorous a response which can transform a raised scar into an indented depressed scar. Cortisone injections can also stimulate the formation of new superficial blood vessels. These can be treated using a lvascular aser; see below. Though keloids usually look better after treatment than before, even the best result may leave a mark that looks and feels different from the surrounding skin.

• 5-Flurouracil injections (5-FU):alone or in combination with cortisone injections help flatten keloid scars by interrupting fibroblast activity.
• Cryotherapy: Repeated applications of liquid nitrogen (commonly known as dry ice) have been shown to flatten keloid scarring within a few sessions. Cryotherapy works best on small keloid scars in lightly pigmented skin and can be combined with cortisone injections and laser treatments.
• Laser treatment: Vascular laser treatment targets red blood vessels in keloid scars to improve colour and texture, but often without flattening of the residual scar tissue. Fractional laser resurfacing is sometimes used to help re-organise collagen fibres in keloid scars and can sometimes result in smoothing and flattening. Laser treatments are often combined with a course of cortisone injections.
• Silicone gels and tapes: These are most successful when applied early in the course of keloid or hypertrophic scar formation. Silicone gel is worn continuously 24 hours a day for 2-3 months. Silicone gels are thought to work by stimulating new collagen to grow in a more organised way and may help to reduce pain, swelling and itching.
• Surgical removal of keloid scars is to be avoided in most instances as cutting a keloid  can make scarring worse by stimulating more scar tissue to form.  Some surgeons achieve success by injecting steroids or applying pressure dressings to the wound site after cutting away the keloid. Radiation after surgical excision has also been used.