Clinical Picture: Cholinergic Toxidrome

A 21-year-old female presents after ingestion of an unknown substance with vomiting, profuse diarrhoea, bronchorrhoea, and excessive sweating, along with miosis and muscular fasciculations on examination. Together, these findings constitute a classic cholinergic toxidrome — excessive stimulation of muscarinic and nicotinic acetylcholine receptors.

Mapping the Symptoms (SLUDGE/DUMBELS)

• Muscarinic effects: Salivation, Lacrimation, Urination, Diarrhoea, GI cramps, Emesis, Bronchorrhoea, and sweating — all present in this patient.
• Miosis: Pinpoint pupils are a hallmark muscarinic sign of cholinergic excess.
• Nicotinic effects: Muscular fasciculations and weakness result from overstimulation of nicotinic receptors at the neuromuscular junction.

This combination — copious secretions (bronchorrhoea, sweating, diarrhoea) plus miosis plus fasciculations — is textbook for excess acetylcholine accumulation at synapses, which occurs when acetylcholinesterase is inhibited.

Evaluating the Options

• Corrosive substance poisoning: Causes oral/oesophageal burns, drooling, and pain from direct tissue injury, but does not produce miosis or fasciculations. Ruled out.
• Aluminium phosphide poisoning: Presents with severe vomiting, refractory hypotension, and cardiac arrhythmias (garlic-like odour, phosphine gas release), but does not cause miosis or fasciculations — its toxicity is mainly cardiovascular/mitochondrial. Ruled out.
• Organophosphorus poisoning (correct answer): Organophosphates inhibit acetylcholinesterase, causing acetylcholine to accumulate at muscarinic and nicotinic synapses. This produces exactly the described picture — bronchorrhoea, diarrhoea, sweating, miosis, and fasciculations — making it the most likely diagnosis.
• Zinc phosphide poisoning: Also releases phosphine gas and causes severe GI irritation (vomiting, abdominal pain, diarrhoea) but does not classically cause miosis or fasciculations; its toxicity is predominantly gastrointestinal and cardiotoxic, not cholinergic.

Conclusion

The presence of miosis and muscular fasciculations alongside profuse secretions (bronchorrhoea, sweating, diarrhoea) is specific to cholinesterase inhibition. Therefore, Organophosphorus poisoning is the correct diagnosis, not zinc or aluminium phosphide poisoning, which lack the characteristic cholinergic (muscarinic + nicotinic) features seen here.