We know to leave wounds alone while they heal. However, at certain points in the healing process they can really itch and drive you crazy. Why does that itch happen and what are you supposed to do about it?
The first thing to understand is that wounds heal in four stages.
The phases of wound healing are:
1) Hemostasis - clotting and stabilizing of the wound with fibrin and platelets.
2) Inflammation -lasts up to four days. Redness, swelling and warmth occur as white blood cells arrive and prepare to fight infection.
3) Proliferation or Granulation -starts four days after an injury and lasts up to 21 days. The framework of the wound healing is created using collagen and fibroblasts as they prepare for wound contraction or closure. Specialized keratinocytes form the protective outer layer.
4) Remodeling or Maturation - this stage can last up to two years where the internal tissue produces more tensile strength. The wound is vulnerable and susceptible to re-injury during this time, which is why a newly healed area easily can become re-damaged.
The itchy sensation you feel when a wound heals is coming from sensitive nerve cells that are reacting to both chemicals being released and structural stretch on the surrounding skin and wound tissue.
According to Skincare.lovetoknow.com, histamine is released during an injury in response to trauma and the introduction of bacteria. This type of histamine release occurs in the second stage of healing to trigger cells that fight an infection, and to bring in the new cells that will help build the tissue to close the wound.
The Naked Scientist explained an additional theory about why the itch also occurs during the third stage of healing.
Dr. Chris says that it's only recently been discovered that there are itch-specific nerve fibers in the skin. Their sole job is to signal to the spinal cord that an area of skin is being stimulated, which is perceived by the brain as itchy.