■ Why does the wound itch?
Human skin is divided into multiple layers. There is a layer of cells at the bottom of the epidermis called mucus layer, which has strong vitality and can continue to grow and reproduce. The superficial wound of epidermal injury is healed by mucosal layer. And too shallow wounds, because the nerves can't get any stimulation, will not feel itchy when they heal, and the itching phenomenon of wounds with large scope and heavy injury is often more obvious.
Wound healing is made up of a new tissue called connective tissue, that is, granulation that grows from the wound. New blood vessels and nerves must grow into connective tissue. Because the blood vessels that grow into connective tissue are particularly dense, it is easy to stimulate the newborn nerves that are crowded with them when they grow rapidly. Nerves are very sensitive, especially newborn nerves. They will feel itchy when they are slightly stimulated.
■ Why does an itchy wound mean healing?
Generally speaking, the process of wound healing can be divided into three stages: the first stage is the process of coagulation and hemostasis; The second stage is that white blood cells gather in the wound to resist infection; The third stage is the proliferation stage, during which new blood vessels and nerves are formed and fresh granulation tissue grows. The itching of the wound occurs in the "last stage" of wound healing-the proliferative stage.
In addition, the itch of the wound is caused by nerve stimulation, but in fact, the regeneration ability of nerve tissue is relatively low, which generally appears in the late stage of wound healing. Therefore, when the wound itches, it also means that the nerve tissue of the wound is regenerated and the local feeling of the wound is restored, which often indicates that the wound will grow well soon.