Scar redness in humans: how long does it persist after incisional and excisional wounding?

The natural history of scar redness in humans has never been formally described, and the point at which normal scar redness fades is unknown.

As part of a randomized, placebo-controlled, clinical trial investigating the effects of various doses of transforming growth factor-beta3 on scar quality, the authors observed the process of scar redness and maturation in non-drug-treated incisional and excisional wounds made on the upper inner arms of 103 volunteers. Scar photographic images were assessed by a review panel to ascertain the month during which redness faded for a particular scar. Scar histology documented the level of inflammation and angiogenesis.

Scar redness faded at an average of 7 months. Scar redness for incisions faded significantly faster than excisions (p = 0.0001, Kruskal-Wallis test), and significant differences were also seen between anteriorly and posteriorly placed scars for incisions (p = 0.0008) and excisions (p = 0.0035), respectively. Month 12 histologic examination revealed the absence of any ongoing inflammatory processes in all scars.

Scar redness fades on average at 7 months. This is influenced by the wound type and position. The authors advocate the use of the term "rubor perseverans" to describe the physiologic redness of a normal scar as it matures beyond the first month, a process that does not involve inflammation.