This initial phase of wound healing results in a classic sign of hyperemia around the wound site due to increased vasodilation as the body rushes cellular elements to the site of the wound. Prolongation of the inflammatory phase can indicate infection, with the usual duration lasting 24-72 hours. The second phase of the cascade is known as proliferation or regeneration. It is said to last from day four to day twenty-four, although the duration may last longer based on the wound. Granulation, fibrous tissue formation, collagen deposition, epithelialization, and contraction of the wound are classic signs of this phase.
Granulation tissue has a clean appearance due to collagen and new blood vessel formation.
Macrophages are the dominant cells in the proliferative phase and are key cells in the immune system. Macrophage activity is thought to be directly related to healing. Inactive macrophages mean the wound cannot heal. It is important to recognize the importance of this cell in wound healing. Failure to move into the granulation phase can indicate the presence of some other factor inhibiting healing.