A 40-year-old man dies after swallowing a corrosive poison. At autopsy there is a greyish-white membrane covering the mouth, pharynx and oesophagus, intense gingivitis with a pronounced metallic taste reported before death, bloody stools with marked tenesmus, and shrunken pale kidneys showing tubular necrosis. Which poison fits this picture?
- A Mercuric chloride ✓
- B White phosphorus
- C Arsenious oxide
- D Nitric acid
Correct answer: A. Mercuric chloride
Explanation
Mercuric chloride (corrosive sublimate) causes a characteristic greyish-white coating of the mucosa from coagulated protein, violent tenesmus with bloody colitis, marked salivation with metallic taste, and acute tubular necrosis of the kidneys. Arsenic produces watery rice-fluid purging rather than tenesmus-dominant dysentery and lacks the metallic taste. Phosphorus causes fatty liver and jaundice, and nitric acid gives yellow xanthoproteic staining of the mucosa.
Reference: Essentials of Forensic Medicine and Toxicology, R.K. Narayan Reddy, 33rd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.