Datura (Dhatura/jimsonweed) poisoning classically produces the triad of hyperthermia, delirium, and which of the following ophthalmic signs?
- A Bilateral fixed dilated pupils (mydriasis) with absent accommodation ✓
- B Pinpoint miosis with lacrimation
- C Nystagmus with convergent squint
- D Cherry-red macular spot
Explanation
Datura stramonium contains atropine, hyoscine (scopolamine), and hyoscyamine — all potent anticholinergic alkaloids. The classic anticholinergic toxidrome is described by the mnemonic: 'hot as a hare, dry as a bone, blind as a bat, red as a beet, mad as a hatter'. The ocular finding is bilateral fixed dilated pupils (mydriasis) with cycloplegia (absent accommodation) due to muscarinic receptor blockade in the iris sphincter and ciliary muscle. Miosis is characteristic of opioid or cholinergic toxicity. The physostigmine antidote crosses the blood-brain barrier.
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.