A victim of a house fire is found dead. At autopsy, the body shows the pugilistic posture. Soot is absent from the trachea and lower airways; carboxyhaemoglobin is 5%. The MOST likely interpretation of these findings is:

• A The victim was alive during the fire but escaped smoke inhalation
• B The victim was dead before the fire started (postmortem burning) ✓
• C The fire was caused by natural gas, which produces no soot
• D The low COHb is due to postmortem redistribution from decomposition

Explanation

The pugilistic posture (flexion of limbs due to heat shrinkage of muscle proteins) occurs whenever sufficient heat is applied whether the victim is alive or dead—it is NOT a vital reaction. The critical vital reaction markers for antemortem fire exposure are: soot in the trachea/lower airways, cherry-red lividity, and COHb >10% (usually >20% in significant smoke inhalation). A COHb of 5% and absence of airway soot indicate the victim was dead before the fire started—either killed beforehand or died of other causes. This combination is classic for postmortem conflagration.

Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.