At scene examination 18 hours after death in a tropical climate (ambient temperature 35°C), a body exhibits fixed lividity, full rigor mortis, and an unusual cherry-red discoloration of lividity and underlying tissues. There is no smell of bitter almonds. The MOST likely cause of death consistent with the cherry-red discoloration in this setting is:
- A Carbon monoxide poisoning ✓
- B Cyanide poisoning
- C Hypothermia
- D Nitrite poisoning
Explanation
Cherry-red or carmine-red lividity and tissue discoloration is the hallmark of carboxyhaemoglobin formation in carbon monoxide poisoning. COHb has a brilliant cherry-red color that persists even after death, making it distinctive at autopsy. Cyanide poisoning can also cause cherry-red color (venous blood oxygenation due to cytochrome oxidase inhibition) and classically emits a bitter almond odour — the absence of this odour makes CO more likely. Hypothermia causes pink lividity due to preserved oxyhaemoglobin in cold environments. Nitrite poisoning causes methaemoglobinaemia, producing chocolate-brown discoloration.
Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.
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Written and medically reviewed by the StethoPrep medical team.