Acute inflammation is a physiologic process which occurs in normal wound healing; the stages of healing are hemostasis, inflammation, proliferation/granulation, and remodeling/maturation. The inflammatory stage is when the body brings all the different cells to the site of injury to "clean up." The stage is characterized by pain, heat, redness, and swelling. People with disease processes such as autoimmune disease, obesity, diabetes, atherosclerosis, etc. are at higher risk of developing non-healing wounds. It's like the wound becomes "stuck" in the inflammatory phase. This can happen for several different reasons. There might be a large amount of dead tissue, high bacterial counts, persistent or recurrent infection, biofilms, and/or failure at the cellular level to heal the wound. The cells which were brought to the site of the injury at the beginning of inflammation (a big one is matrix metalloproteases (MMPs)), do not decrease like they would in normal healing. MMPs are found in very high levels in chronic wounds. This impedes healing, since the MMPs continue to breakdown tissue in the wound rather than transitioning to the next stage of healing. Also, macrophages, which are present at the beginning of the inflammatory stage, normally release chemicals to help move the wound into the proliferation stage. Macrophage activity has noted to be impaired in patients who have poorly controlled diabetes.
Published on Jul 11, 2012