A Clue on the Skin: A Systematic Review on Immunohistochemical Analyses of the Ligature Mark

Abstract

Background: A ligature mark is a common injury in cases of hanging or strangulation. Estimation of age and vitality of the ligature mark can be crucial for differentiating antemortem and postmortem wounds and to distinguish between simulated suicidal hanging or accidental strangulation to conceal a crime and not simulated events. The immunohistochemistry has been recommended by several Authors as a reliable tool to determine whether an injury was sustained during life or not. Unfortunately, no general agreement on the immunohistochemical markers to be used has been found among the scientific community. The aim of the study was to detect the type and function of the immunohistochemical markers useful in the assessment of the vitality and age of the ligature marks for routine diagnostics. Methods: Papers available on Pubmed, Scopus, and Web of Science were reviewed according to the PRISMA statement. Results: Only eight papers satisfied all the following inclusion criteria: full texts in English dealing with human ligature marks and immunohistochemistry published on impacted or indexed scientific journals. Conclusions: The assessment of the vitality of a ligature mark is still a challenging topic in forensic science. Under ideal conditions and in compliance with autopsy protocols, the diagnosis of death by hanging or strangulation on fresh bodies can be better supported by autopsy findings other than a ligature mark. The validation of immunohistochemical markers on large series could be of help in doubtful cases and differential diagnoses.