Using the Inflammatory Cell Infiltrate to Estimate the Age of Human Burn Wounds: A review and immunohistochemical study

Abstract

If neutrophils predominate, the wound is probably less than a couple of days old. When macrophages are abundant the wound is probably a few days to weeks old. However, as expected from the review of the literature, the inflammatory cell infiltrate may be low or absent in burn wounds, which can render determination of the age of burn wounds difficult.

IL‐5‐overexpressing mice exhibit eosinophilia and altered wound healing through mechanisms involving prolonged inflammation

“…Leucocytes are imperative in healing wounds and are predominantly involved in the inflammatory and granulation stages. Infiltration of macrophages, 1 neutrophils 2 and monocytes 3 into wounds occurs in a distinctive order 4 and while present in the wound they are responsible for phagocytosis of damaged tissue and invading pathogens, as well as secretion of chemo‐attractants. In addition to these leucocytes, mast cells 5 and eosinophils 6 have also been implicated in the healing process.…”

The science behind the quest to determine the age of bruises—a review of the English language literature

“…However, data from animal experiments may not be applicable to humans [33]. Neutrophils are not present in normal skin, thus the finding of any would be regarded as signifi cant [143]. Emigration of neutrophils within minutes has been reported in blunt trauma skin wounds in humans [144].…”

“…Nonetheless, traditionally, neutrophils would not be expected to be numerous until several hours have elapsed from the time of injury [149,150]. Macrophages are present in normal skin [143] making it more difficult to determine when an infiltration has commenced. They are increased from around 12 h in traumatic lesions of the human brain [146,151].…”

“…Erythrophagocytosis appears from 12 h in brain injuries [146,152] to 3 days in skin wounds [145]. Marked variation of the inflammatory infiltrate in burn wounds of the same age occurs between subjects [143] and the same could occur in bruises--particularly if there is devitalization of tissue. The presence of hemosiderin can be demonstrated using Perls' stain [153] at 3 days in human skin wounds, [145,154] but earlier in mice [32] and other animals [142].…”

“…Notwithstanding this, the finding of a local vital reaction may be the only sign that a bruise occurred antemortem [149,[209][210][211]. An established infiltrate of neutrophils would be expected to imply that a bruise occurred during life, as neutrophils are not present in normal skin [143]; however, it has been observed that neutrophil emigration can occur after death in response to cytokines ]212]--at least in mice [213]. Also, care must be taken to exclude inflammatory cells that are present due to passive 'drift' [145].…”