A 35-year-old male is found dead with cherry-red discolouration of skin and lividity. The most likely toxic cause is:
- A Cyanide poisoning
- B Arsenic poisoning
- C Carbon monoxide poisoning ✓
- D Organophosphorus poisoning
Correct answer: C. Carbon monoxide poisoning
Explanation
Carbon monoxide binds haemoglobin with 240 times greater affinity than oxygen, forming carboxyhaemoglobin, which imparts a characteristic cherry-red (carmine) colour to the blood, lividity, skin, and organs. Cyanide also causes cherry-red discolouration but does so due to blocking cytochrome oxidase, preventing oxygen utilization — however, CO is far more common and is the classic answer in this context.
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.