Mushroom poisoning in the UK: Review of enquiries received by the National Poisons Information Service

Objective: To assess the epidemiology of mushroom poisoning in the United Kingdom between January 2008 and 14th November 2011. 

Methods: Enquiries to the National Poisons Information service were reviewed retrospectively and analysed to evaluate patterns of exposure. 

Results: A total of 946 enquiries were analysed; this accounted for 0.4%, 0.37%, 0.63% and 0.52% of all enquiries in 2008, 2009, 2010 and 2011 respectively. Fifty-four percent (n = 515) of the total involved children under 15 years and 45% (424) involved children < 5 years. In this group 81% were reported to have ingested an unidentified mushroom; 77% were asymptomatic, 12% reported gastrointestinal symptoms only and 4 cases developed moderate features. Eighty-four percent of all enquiries occurred between June and November (peak in September) indicating a possible influence of climatic conditions on growth. Enquiries that reported symptoms either at time of enquiry or at follow-up were reviewed to determine the time of onset of symptoms. Of these (n = 332) 126 were excluded due to insufficient detail on the record or unconfirmed exposure. In the remaining 206 enquiries, 72% reported symptoms within the first 6 hours with 28% reporting later onset of symptoms. In the under 5 age group who reported symptoms only 34 enquiries contained sufficient data to determine time of onset and in that group only 2 developed features later than 6 hours post ingestion. None of those followed up developed severe features. Forty (5%) cases had a poisoning severity score of moderate or severe. In this group 21 were regarding an unknown species, 9 concerned psilocybin or magic mushrooms and the other 10 were regarding known species of mushroom including Amanita and Cortinarius species. 

Conclusion: Seasonal poisoning is not a new phenomenon; the suggestion that availability is a major determinant in the risk of poisoning particularly in children is supported by these data. Foragers and pickers who consume larger quantities of mushrooms tend to develop more severe symptoms. Education of the public concerning consumption of mushrooms and education of health personnel regarding early treatment and transfer to hospitals with appropriate facilities are important for improving outcome.