Postmortem skin changes

Postmortem skin changes include livor mortis, vibices, Tardieu spots, and marbling. Livor mortis refers to the bluish-purple discoloration (lividity) under the skin of the lower body parts due to gravitation of blood after death. Onset of lividity, its location and color, provide information on the time and cause of death. Vibices are pale marks on a dead person's skin that are caused by dermal pressure (e.g. marks around the neck from a rope). Dark pinpoint spots (Tardieu spots) are seen when capillaries rupture due to increased gravitational pressure (e.g. in the legs of a hanged person). A prominent purple discoloration of subdermal vessels appears later in the process of decomposition and leaves a marbling pattern.

• Definition: postmortem discoloration of the skin, resulting from blood pooling into the interstitial tissues under the force of gravity
• Occurence
  • At least 30 minutes to 2 hours after onset of death
  • Maximum observed at 6–12 hours
• Location
  • Blood pools in areas of dependency under the force of gravity
    • Person died lying face up: back of the corpse
    • Hanging death: feet, fingertips and ear lobes
    • Drowning: face, upper chest, hands, lower arms, feet, and calves
  • Lividity is evident on the ear lobes and the nail beds
  • Also occurs in visceral organs (e.g., lungs)
• Features
  • Redistribution: lividity can be altered up to 6 hours after onset of death
  • Blanching: skin will turn white when applying pressure within the first ∼ 12 hours
• Color: the intensity of color depends on the amount of hemoglobin in the blood
  • Bluish-purple: normal lividity
  • Greenish-red: hydrogen sulfide (produced in decaying organic matter)
  • Dark brown: phosphorus poisoning
  • Brownish-red: poisoning with methemoglobin-forming substances (such as nitrite or aniline)
  • Pale pink (barely pronounced): blood loss, severe anemia, severe hemorrhage
  • Cherry red: carbon monoxide poisoning
  • Bright red: cyanide poisoning

Livor mortis occurs approx. 30 minutes to 2 hours after the onset of death and is the first definite sign of death!

References:^{[1][2][3][4][5][6][7][8]}

• Vibices: pale marks caused by pressure (e.g. from a rope in hanging death or generally from tight clothing, e.g., socks, belt, and bra)
• Tardieu spots: dark pinpoint spots develop in dependent areas (e.g., in the legs of a hanged person due to increased gravitational pressure)
• Features of decomposition
  • Venous patterning (marbling): prominent purple discoloration of subdermal vessels
  • Degloving: Thermal exposure, immersions, or advanced decomposition of skin and tissues result in degloving of skin (common in hands and feet).
  • Multisystemic processes : mummification, putrefaction

References:^[1][9]

1. Presnell SE, Denton JS. Postmortem Changes. Postmortem Changes. New York, NY: WebMD. http://emedicine.medscape.com/article/1680032-overview. Updated: October 13, 2015. Accessed: May 26, 2017.
2. Noriko T. Immunohistochemical studies on postmortem lividity. Forensic Sci Int. 1995; 72 (3): p.179-189.
3. Prahlow J. Forensic Pathology for Police, Death Investigators, Attorneys, and Forensic Scientists. Humana Press ; 2010
4. Miletich JJ, Lindstrom TL. An Introduction to the Work of a Medical Examiner. ABC-CLIO ; 2010
5. Tsokos M. Forensic Pathology Reviews. Springer Science & Business Media ; 2007
6. Gannon K, Gilbertson DL. Case Studies in Drowning Forensics. CRC Press ; 2014
7. Hammer R, Moynihan B, Pagliaro EM. Forensic Nursing. Jones & Bartlett Publishers ; 2011
8. Post-Mortem Hypostasis. http://www.forensicpathologyonline.com/e-book/post-mortem-changes/post-mortem-hypostasis. Updated: January 1, 2013. Accessed: October 9, 2017.
9. Biswas G. Review of Forensic Medicine and Toxicology. JP Medical Ltd ; 2012