Livor Mortis and Forensic Dermatology: A Review of Death-Related Gravity-Dependent Lividity and Postmortem Hypostasis.

Livor mortis is an early postmortem change; it is also referred to as dependent lividity or postmortem hypostasis. This is a narrative review; the PubMed search engine was used to obtain citations of relevant articles. The following terms, by themselves and in combination, were used to screen for appropriate published manuscripts that described the features of livor mortis: color, cutaneous, dermatology, fatal, forensic, hypostasis, lividity, livor, mortis, and postmortem. The articles obtained from those searches were reviewed, and the relevant references cited by the articles were evaluated. Lividity typically presents as small blanchable red-purple macules and patches on the dependent areas of the decedent; it is usually observed within two hours after the person has died; however, it can be noted as early as 20 minutes after death. After four to six hours, hypostasis becomes more readily apparent; the smaller lesions become confluent and occur in larger regions of the body. However, contact pallor is observed in the dependent areas affected by direct pressure; these sites do not become red-purple. Livor mortis is usually "fixed," and not blanchable, after eight to 12 hours. A bruise is the most common condition in the clinical differential diagnosis of lividity. The onset and duration until fixation of postmortem hypostasis are variable; lividity is also influenced not only by temperature but also by other factors. Livor mortis has at least three potential applications in forensic medicine. The first is that lividity, usually in combination with information from other postmortem changes, can be used to estimate the time since death; however, livor mortis is not reliable as an independent observation for establishing a range for the postmortem interval. The second is that livor mortis, when fixed, can be very helpful to establish that a decedent has been moved after death. The third is that the color of the lividity may possibly provide information regarding the cause of death; for example, carbon monoxide intoxication, hypothermia, or cyanide poisoning can be associated with cherry-red or pink lividity. New discoveries in medical technology have provided the ability to incorporate the use of spectrophotometric analysis of lividity to provide an objective assessment of postmortem hypostasis and correlate the information to more accurately estimate the postmortem interval.