Neuropsychiatric symptoms following the consumption of Lanmaoa asiatica, a poisonous mushroom native to Yunnan

Objectives To describe and analyze the clinical characteristics and outcomes of Lanmaoa asiatica poisoning cases. Methods We conducted a retrospective study of Lanmaoa asiatica poisoning cases admitted to the emergency department of the First People's Hospital of Yunnan Province from January 2023 to December 2023. Results A total of 81 patients were admitted, with ages ranging from 14 to 84 years and a median age of 42.5 ± 14.6, predominantly female (72.8%). The peak poisoning cases were observed in July (n = 55, 67.9%). The commonest clinical presentation was the mixed neuropsychiatric and gastroenteritic type (64.2%), while 24.7% of patients presented with neuropsychiatric symptoms only and 11.1% of patients presented with pure gastroenteritic symptoms. The most common first symptom was visual hallucination (n = 56, 69.1%), followed by gastrointestinal symptoms such as nausea (n = 44, 54.3%) and vomiting (n = 36, 44.4%). Around 69.4% of patients had delayed onset of neuropsychiatric symptoms of 12–24 h after mushroom intake and 78.7% of patients had onset of gastroenteritic symptoms within 6 h after ingestion. Laboratory tests showed normal blood routine, liver function, kidney function, cardiac enzymes, and coagulation function. The median length of stay was 3 days, and no fatalities were reported. Conclusions Lanmaoa asiatica poisoning peaked in July. The commonest clinical presentation was the mixed neuropsychiatric and gastroenteritic type. The most common first symptom was visual hallucination. The incubation period for gastrointestinal symptoms was shorter than neuropsychiatric symptoms. Short hospitalization and absence of organ function damage was observed in Lanmaoa asiatica poisoning.