How Scars Form²

Scar formation is a natural part of the healing process that occurs when the skin repairs wounds caused by accident, surgery or disease. The time skin takes to heal will vary depending on the degree of damage, and the longer it takes to heal the greater the chance of a noticeable scar.

It is important to know, that scarring is considered to be the final stage of wound healing and all (partial thickness and full thickness wounds) will form scars, but not all of the scars will become abnormal scars. Normal scars will develop during the first 48 hours after wound closure and can fade within 3 months, whereas abnormal scars can occur up to 18 months later.¹

During the first phase of the scar formation (“inflammation”) there is little difference seen clinically between an abnormal and a normal scar. The body produces collagen fibres to close the wound and the affected area of the skin will appear red and thick.

This procedure continues in the second phase (“proliferation”) where the collagen fibers are secreted into granulation tissue and are arranged in a concentric or whirled pattern with the nodules growing and eventually becoming thickened and compacted bands lying parrallel to the surface.

In the third and last phase (“maturation”), normally there is a balance between the formation of collagen and the destruction and removal of collagen. This balance is regulated by cytokines (or protein mediators) and other tissue inhibitors. Normally, “type III collagen” is replaced by “type I collagen”, with closer cross-links resulting in increased wound strength. When this remodelling balance is disrupted, abnormal scar production occurs.

Epidemiology of scars

More than 100 million patients in the developed world acquire scars each year. Some of them cause considerable problems and are treated in 55 million elective operations and 25 million operations following trauma. In the developed world, there are an estimated 11 million keloid scars and 4 million burn scars. 70% of the latter occur in children. Globally, the numbers are estimated to be much higher.

1. 1. Brissett AE, Sherris DA, Facial Plast Surg 2001; 17:4
2. 2. Guilbaud, J, Euro Derm Rev 2010; 5:2-8