Cholinergic crisis in Lycoris radiata poisoning: A case of delayed onset and prolonged symptoms.

Lycoris radiata, commonly known to contain alkaloids such as lycorine and galanthamine, is toxic and is easily accessible in East Asian countries, including Japan. Lycorine is a central nervous system and gastrointestinal irritant, whereas galanthamine, a carbamate, exhibits reversible acetylcholinesterase inhibition. Symptoms of Lycoris radiata poisoning are generally acute and resolve quickly. We present a case of an 83-year-old woman with impaired consciousness that presented to our hospital. The patient's presentation initially was not significant; however, a rapid progression of symptoms occurred eight hours after admission, including miosis, hypersalivation, increased airway secretions, vomiting, diarrhea, and myoclonus. A rapid hemodynamic and respiratory function deterioration necessitated vasopressor administration and mechanical ventilation. Given her toxidrome, we suspected a cholinergic crisis and measured her serum butyrylcholinesterase levels, which were considerably low. Initially presuming organophosphate poisoning with acetylcholinesterase inhibition, we administered pralidoxime. Her condition subsequently improved, allowing for de-escalation of support; which aligned with increasing serum butyrylcholinesterase levels. The patient disclosed ingestion of Lycoris radiata, and an analysis of her garden plants revealed lycorine and galanthamine, confirming the diagnosis. Acute Lycoris radiata poisoning can result in a severe clinical course. Furthermore, the onset of a cholinergic toxidrome may be delayed following ingestion, and the toxidrome may persist for a prolonged period.