Immunologic reactions in chronic wounds.

Although, healing is initiated by local inflammation, excessive or prolonged inflammation may delay healing and increase scar potential. Inflammatory cascades in the wound's microenvironment are triggered by complement degradation products; polymorphonuclear leukocyte products; oxygen free radicals; enzymes, particularly proteinases; and microbial products. Infection, ischemia, necrotic or severely damaged tissue, or foreign matter propel and prolong inflammation and challenge host defenses, leaving the patient susceptible to further microbial invasion. Occlusion dressings can minimize necrotic tissue by preventing desiccation, aiding debridement, and providing a barrier against exogenous pathogenic organisms, thus limiting the resulting inflammatory cascade.