What if you ignore an itch

Why do wounds itch when they heal?

Ouch! Slipped the potato knife once and there is a bloody cut in the finger. And then that too: the next day the wound itches uncomfortably and is reddened. What actually happens when you are injured, and why does such a wound itch when it heals?

First the good:

If the wound is bleeding, the body knows exactly what to do. The first thing to do is to contract the blood vessels in the injured area. Platelets attach to the narrowed areas. They stick together and close the blood vessel. A network of sticky fibers is created - the fibrin.

It also covers the wound and closes it. This process is called Blood clotting. A great invention of nature, without it we would bleed to death with every deeper scratch!

The phagocytes now reach the wound. They fight pathogens that have got into the wound and remove clotted blood and broken cells. It doesn't matter that the skin around the wound becomes a little inflamed - on the contrary: it even helps with healing.


The phagocytes set in their work histamine free. This important substance triggers further wound healing processes. But histamine also triggers something else: itching! To do this, it docks to certain receptors. They pick up sensations such as pain or itching and pass the signal on to the brain.

The wound is now like on a construction site. Everything that has broken is renewed: vessels, fibers, connective tissue, nerves ... There is a lively exchange of messenger substances. Growth factors ensure that the tissue is rebuilt. This also releases histamine and some other substances that are suspected of causing itching. When nerve endings heal, they send new signals to the brain and that too is perceived as itching.

So it's true: if it itches, then it heals! The crust that forms on top of the wound after a while can also cause itching. It is quite rigid and the skin is immobile at the point. If you move the skin in the area anyway, it can also irritate the itch receptors.

So itching is a coincidental side effect of wound healing. It is even more annoying: if you scratch a freshly closed wound again, the wound healing has to start all over again. It is best to put a plaster on it and leave the wound alone if possible.