Immunohistochemical parameters for the age estimation of human skin wounds. A review

The immunohistochemical detection of stringlike ramifying structures positive for fibronectin in wounds aged at least a few minutes provides valuable information on the vitality of skin lesions even before the appearance of neutrophilic granulocytes. Positive reactions for tenascin or collagen type III indicate postinfliction intervals of at least 2-3 days, whereas vital reactions for collagen type V or VI occur earliest 3 days after wounding. Collagen type I appears as spotlike fibroblast-associated reaction products in injuries aged 4 days or more, while typical stringlike ramifying fibers indicate a postinfliction interval of at least 5-6 days. Fibroblasts positively staining for laminin or heparan sulfate proteoglycan can be detected in wounds with a survival time of approximately 1.5 days or more and collagen type-IV-positive cells occur earliest 4 days after wounding, followed by alpha-smooth muscle actin expressing fibroblasts after 5 days or more. Basement membrane fragments positive for laminin, heparan sulfate proteoglycan, or collagen type IV or VII indicate a wound age of at least 4 days, and a complete restitution of the epidermal basement membrane in (surgical) wounds can be observed earliest 8 days after wound infliction. Positively reacting basement membrane fragments are absent up to a wound age of < 13 days, and the evidence of an incompletely rebuilt basement membrane indicates a postinfliction interval of less than approximately 22 days. A continuous staining of the basal cells of the newly formed epidermis for cytokeratin 5 occurs earliest 13 days after wounding, and the absence of a complete staining provides information on a wound age of < 24 days.