Why doesn’t the skin always heal properly after an injury?

A cut, a scratch, a burn, chicken pox, acne, an infection: they can all cause scars. They come in all shapes and sizes, from hard white cables to soft pink elevations and from pits to large placards. But why does our body actually create scars? Do they have a function?

A specialist works at the Radboud University Medical Center in Nijmegen who is happy to answer the question. Madelon Vonk is a rheumatologist. But… isn’t rheumatism the disease of inflamed joints? What does that have to do with scars? “I specialize in complex autoimmune diseases,” says Vonk. “These are diseases in which the immune system attacks its own tissues, instead of foreign substances or pathogens. Rheumatism is a collection of such autoimmune diseases. My specialization is systemic sclerosis: a condition in which people develop scar tissue throughout their bodies, including in their organs, due to a fault in the immune system.”

Collagen and elastin

Normally, scar tissue is a byproduct of wound healing, Vonk explains. It is a form of connective tissue. We have that in our entire body; it gives shape and strength to organs and tissues and consists mainly of the proteins collagen and elastin. The first is firm, the second elastic.

Our healthy, supple skin is also packed with connective tissue. This is made by fibroblasts: loose, elongated cells that are found everywhere in our body and contribute to the constant renewal of connective tissue. “Normally there is a good balance between building up and breaking down,” says Vonk. “But as soon as the skin is damaged, the fibroblasts become extra active. They try to restore the shape of the tissue as quickly as possible – rather than its function. In fact, that balance is disrupted: collagen production goes into overdrive.”

But at that moment the scar is useful, she emphasizes. The rapid formation of connective tissue prevents the wound from being open for a long time, resulting in too much blood loss and infections. “In addition, the fibroblasts contract, pulling the wound edges together. The collagen formed helps to keep the wound closed. But sometimes that happens a bit exaggerated.”

Stretchability and sweat production

Then a thickening occurs: the scar. It has the same components as healthy connective tissue, but the 3D structure is different. The collagen fibers lie along each other in a cable-like manner and are more strongly interconnected than in normal connective tissue. You then lose the normal functions of the epidermis, including elasticity, sense of touch and sweat production. “The extent to which this happens can vary greatly,” says Vonk. “Some scars are flexible and disappear gradually. Others are thick and hard, and remain for life.”

This depends, among other things, on the severity and depth of the wound and any infections, but other factors also play a role. For example, the location of the wound, your age, health and hereditary factors. “Systemic sclerosis involves scarring in all kinds of tissues at the same time,” says Vonk. “There are probably both genetic and environmental factors involved, but we still know little about the cause.” It is a serious disease that cannot be cured; in the Netherlands there are approximately 3,500 patients.

And, is there anything that can be done about ‘normal’ scars on the skin? For example, do vitamin E creams help? “As far as I know, that has never been proven,” Vonk answers. “Massage sometimes has some effect. Then you stimulate blood circulation and the connective tissue becomes softer. It is then converted back into healthy tissue more quickly.”