Why do skin injuries cause vitiligo?

Last Updated on 29th May 2023 by Caroline Haye

Physical trauma is a trigger

If you, or a loved one, suffer from vitiligo you will know how traumatic it can be.  The psychological trauma of any disfigurement (e.g. a burn, scar or birthmark) can be difficult to deal with, especially if it affects your face.  But in this post I want to talk about another kind of trauma: the physical kind… Because if you have noticed new patches appearing in places where your skin was damaged (typically after a cut, scratch or insect bite) then you’ve probably wondered why do skin injuries cause vitiligo?

The Koebner effect

Physical trauma does not have to be dramatic to result in pigment loss. For example, it can include, minor cuts, scrapes, stings and injections, tattoos and piercings, and even friction from tight clothing or other rubbing or irritation… As well as the major league stuff like surgical incisions and serious flesh wounds. The appearance of new vitiligo lesions (white patches) in the exact same place as these injuries is called isomorphic response. But we more often refer to it as the Koebner phenomenon, Koebner effect or koebnerization. (Named after the 19th century German dermatologist Heinrich Koebner who first described the effect.)  

Skin injuries are not the root cause of vitiligo

Although there remains a lot for scientists to discover about the root cause of vitiligo, there is now plenty of evidence that it is a genetic one… And that the process is an inflammatory, autoimmune one. This means that people who carry a certain gene mutation are more susceptible to losing skin pigment that everyone else. But it usually takes something, like a trauma or injury, to trigger the de-pigmentation process. And the pigment loss occurs because our immune system responds to skin trauma by launching an attack on our pigment-producing cells. So, external injuries to the skin are not the source of the condition but they are a common trigger.

Interestingly, even people who do not go on to develop vitiligo, as such, sometimes experience a loss of pigment at the site of inoculations and surgical scars. And some people never regain their normal skin colour following minor cuts and abrasions. I have not been able to find any information as to why this happens. But maybe even people who do not carry the “vitiligo gene” can experience a limited autoimmune response in certain circumstances.

Scientific research into the Koebner phenomenon

Some of the historical research into this subject can be found here.  And more recent research, carried out by Dr Matteo Bordignon of the University of Padua, Italy, has identified a protein (MIA: Melanoma Inhibitory Activity) that may be the main factor affecting the development of vitiligo.  According to Dr Bordignon, this protein is not only the reason why people with vitiligo – contrary to popular belief – have a lower risk of skin cancer, but it also interferes with the normal adhesion of melanocytes (pigment-producing cells) to the basal membrane in the skin, causing them to detach and white patches to develop in those areas. His findings add weight to other research suggesting that physical trauma often plays a role in this process of melanocyte detachment.

All of this research has been significant in the search for effective medical vitiligo treatments… A search which is of course still ongoing. But, in the meantime, our knowledge of koebnerization can certainly help us to avoid vitiligo triggers in our everyday life. Naturally, no one plans to sustain injuries on a regular basis. But, knowing what we now know, we can perhaps exercise a bit more caution… Glad I didn’t decide to be a stunt double 😉

For further information on the subject of skin trauma and vitiligo triggers, see my other related posts:

Tattoos and vitiligo: 3 pros and 6 cons

Vitiligo susceptibility

My favourite vitiligo clothes labels …

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