A 30-year-old woman ingests a clear household chemical in a suicide attempt. She develops severe abdominal pain, tetanic spasms of the hands, carpopedal spasm, and laryngeal stridor. Serum calcium is markedly low. Which corrosive did she ingest?
- A Concentrated sulphuric acid
- B Nitric acid
- C Oxalic acid ✓
- D Carbolic acid
Correct answer: C. Oxalic acid
Explanation
Oxalic acid binds ionised calcium to form insoluble calcium oxalate, producing profound hypocalcaemia with tetany, carpopedal spasm, laryngismus and convulsions, along with renal tubular damage from oxalate crystals. Sulphuric, nitric and carbolic acids cause local corrosion and shock but do not chelate serum calcium, so tetany from hypocalcaemia points specifically to oxalic acid.
Reference: The Essentials of Forensic Medicine and Toxicology, Reddy, 34th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.