Table 5
Suggested schema for the histological estimation of the time interval from infliction of injury to death in open skin wounds and abrasions
| Time interval | Histology |
|---|---|
| Less than 4 hours | No distinct signs of inflammation. Histological distinction between antemortem and postmortem skin wounds not possible |
| 4–12 hours | 4 hours: some polymorph leucocytes perivascularly |
| 8–12 hours: polymorphs, macrophages, and activated fibroblasts form distinct peripheral wound zone | |
| Polymorphs more frequent than macrophages (5:1). Imminent necrosis in central zone | |
| 12–48 hours | 16–24 hours: relative number of macrophages increases, with polymorph to macrophage ratio falling to 0.4:1 |
| After 16 hours older fibrin stains bright red with Martius scarlet blue, whereas before 16 hours “newer” fibrin stains yellow | |
| 24 hours: the number of polymorphs and amount of fibrin increase to maximum (remain at this value for 2–3 days) | |
| Cut edge of epidermis shows cytoplasmic processes | |
| 24–48 hours: epidermis migrates from the incised edge towards the centre of the wound | |
| At 32 hours and after, necrosis is apparent in the central wound zone | |
| 48 hours: macrophages reach maximum concentration in peripheral zone | |
| 2–4 days | 2–4 days: fibroblasts migrate from the nearby connective tissue to the wound periphery |
| 3 days: epithelialisation of small wounds and abrasions complete; thereafter regenerated epidermis becomes highly stratified and thicker than the normal surrounding epidermis | |
| 3–4 days: capillary buds appear | |
| 4–8 days | 4 days: first new collagen fibres seen |
| 4–5 days: profuse ingrowth of new capillaries; capillaries continue to proliferate until 8th day | |
| 6 days: lymphocytes reach maximum concentration in wound periphery | |
| 8–12 days | Decrease in number of inflammatory cells, fibroblasts, and capillaries; increase in the number and size of collagen fibres |
| >12 days | 12 days: definite stage of regression of cellular activity in both epidermis and dermis. Vascularity of dermis diminishes. Collagen fibres restored. Epithelium shows stainable basement membrane |
| At 14 days fibroplasia reaches its peak. Thereafter there is gradual shrinkage and maturation of connective tissue in the wound |
