Keloids and hypertropic scars Ba Hen Ge Da
An alternative view of collagen mass

A commonly used steroid is triamcinolone injected directly into the scar. This works by increasing the activity of an enzyme called collagenase. This enzyme breaks down collagen so that scars become less thick and red. The steroid does not change the amount of collagen made by the cells nor does it decrease the number of cells making collagen. Its action is primarily to remove some of the excess collagen from the wound. However, this alone is not able to prevent a future proliferation of scar tissues.

The direct infiltration of various forms of cortisone is the most used therapy for scar treatment. The effect of cortisone is (at least partly) the blockade of the iNOS transcription, and therefore a reduction of the collagen production in fibroblasts and a reduction of the alpha2-macroglobulin synthesis (an inhibitor of the collagenesis). In most cases Triamcinolonacetonid (TA) 10-40 mg in pure form is injected. The earlier the treatment starts the better are the prospects of success.
Possible side effects: (especially with the wrong injection technique) includes atrophy of the sub-cutis, change of pigments, teleangiektasis (visible dilated vessels on the skin surface). There is no proof of the effectiveness of topical cortisone creams, ointments or plasters.

Steroids are not usually used immediately after surgery because they decrease inflammation and weaken the wound. In severe scars the benefits of injecting the steroid immediately may outweigh the risk of weakening the scar.