Mushroom Toxicity


Mushrooms are the macroscopic fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source.

  • severe toxicity from mushrooms is rare in humans
  • most symptomatic presentations are a self-limiting gastroenteritis requiring supportive care only
  • lethal hepatotoxicity from Amanita mushrooms must be excluded
    • very rare in Australia
    • accounts for most mushroom related deaths worldwide
  • mushroom identification is very difficult (requires a mycologist) and is often impossible (e.g. mushrooms are unavailable, decomposing, cooked, or partially digested)


  • mushroom toxicity typically occurs from:
    • incorrect collection, preparation, and/or storage of wild edible mushrooms (Gawlikowski et al, 2014)
    • when wild toxic mushrooms are misidentified as an edible species
  • may present as clusters with more than one person poisoned


Clinical presentations can be categorised as:

  • early onset (<6 hours)
  • late onset (6-24 hours)
  • very late onset (>24 hours)


Gastrointestinal (GI), e.g. many mushroom species

  • toxic mechanisms uncertain
  • GI symptoms with onset 30min-3h and resolution in 6-24h

Cholinergic, e.g. Citocybe and Inocybe species

  • muscarine-mediated
  • 30min-2h: cholinergic syndrome

Hallucinogenic, e.g. Psilocybin spp

  • psilocybin-mediated
  • onset in minutes: anxiety, mydriasis, ataxia, tachycardia, dyskinesia, hallucinations, delirium

Disulfram-like; e.g. Coprinus spp

  • coprine-mediated
  • <2h of mushroom ingestion with prior ethanol consumption, lasts 6 hours: N&V, flushing, tachycardia, sweating, chest pain

Glutaminergic, e.g. Amanita muscaria and panterina

  • 30min-2h: delirium, dysphoria, drowsiness, hallucinations, myoclonus, hyperreflexia, seizures

Epileptogenic, e.g. Gyromitra spp

  • gyromitrin-mediated symptoms
  • <6h: GI symptoms
  • CNS symptoms: headache, ataxia, fatigue, nystagmus, tremor, vertigo, seizures (rare)
  • 2-3 days: delayed hepatotoxicity (rare)
  • 1-3 days after hepatotoxicity: haemolysis and methaemoglobinaemia

Immunohaemolytic, e.g. Paxillus spp

  • <3h: GI symptoms
  • days: haemolytic anemia, immune-complex nephritis and renal failure

Pneumonic, e.g. inhalation of dried Lycoperdonosis spores

  • <6h: N&V, rhinitis
  • days: pneumonia


Hepatotoxic, e.g AmanitaGalerina and Lepiota spp

  • hepatotoxic cyclopeptides: amatoxins, phallotoxins and virotoxins
  • 6-24h: GI symptoms
  • 18-36h: transient improvement, asymptomatic transaminitis
  • 2-6d: severe gastroenteritis, hepatic failure and pancreatitis


  • acromelic acids
  • 24-72h onset, with resolution over 8 days to 5 months: burning pain, redness and swelling of hands and feet, exacerbated by heat and cold


Nephrotoxic, e.g. Cortinarius  and A. smithiana spp

  • orellanine-mediated
  • 24-36h: headache, GI symptoms, flank pain progressing to interstitial nephritis and renal failure

Rhabdomyolysis, e.g. tricholoma and Russula  spp

  • onset 24-72h: fatigue, myalgias, muscle weakness and myocarditis (very rare)



  • Exposure history
    • Description of the mushroom (e.g. color, texture, cap appearance)
    • How much was eaten?
    • Recent alcohol intake? (f suspected disulfram-like reaction)
    • Location and season of mushroom collection/ purchase?
    • How was mushroom collected, prepared, and stored?
    • Anyone else exposed or ill?
  • Symptom history
    • features of toxicity syndromes describe above
    • Time course (onset and duration after mushroom exposure)


  • Often non-specific
  • Assess for:
    • Dehydration secondary to gastroenteritis
    • Specific toxidromes (e.g. cholinergic)
    • Features of organ failure (e.g. hepatic encephalopathy)


  • guided by clinical assessment
  • check LFTs and renal function first if GI symptoms present >6 hours after exposure
  • consider: FBC, UEC, CMP, LFTs, coagulation profile, CK, glucose, ECG, blood gas and lactate
  • mycologist examination of mushroom samples



  • rarely necessary
  • life-threats include:
    • severe gastroenteritis causing hypovolemic shock
    • seizures or coma
    • cholinergic crisis
    • complications of organ failure (e.g. hepatic toxicity, renal toxicity)

Supportive care and monitoring, may include:

  • neurological observations for seizures, coma and paralysis
  • delirium management
  • glucose monitoring
  • cardiac monitoring
  • rehydration and antiemetics
  • monitor LFTs for 48 hours if suspected cyclopeptide hepatotoxin


  • activated charcoal 50g (1g/kg in children) if onset of GI symptoms occurs >6 hours post-ingestion

Enhanced elimination

  • consider multi-dose activated charcoal if suspected cyclopeptide hepatoxicity as alpha-amantin undergoes enterohepatic circulation


  • cyclopeptide hepatoxicity (e.g. GI symptoms onset >6 hours or increasing transaminases)
    • N-acetylcysteine
    • penicilin 1 MU/kg/day
    • silibinin 5 mg/kg IB over 1 hour then 20 mg/kg/day for up to 3 days
  • cholinergic syndrome
    • atropine
  • seizures due to Gyromitra  mushrooms
    • pyridoxine (similar management to isonizid toxicity)


  • discharge home if risk assessment does not predict severe toxicity and:
    • asymptomatic, or
    • early onset GI symptoms are resolving and patient is clinically well (check LFTs and renal function first if lasts >6 hours)
  • observe in hospital:
    • significant symptoms
    • risk assessment predicts potential for severe toxicity
  • admit to HDU/ ICU:
    • coma or CNS dysfunction
    • liver or renal failure (may require transfer to a specialist center)


  • Most mushroom toxicity presentations are mild or resolve with supportive care
  • mushroom ingestions which present with gastrointestinal symptoms will recover without complication when provided adequate supportive care.
  • Nephrotoxicity from Cortinarius ingestion may lead to a requirement for haemodialysis (51%), end-stage renal failure (11%) and require renal transplantation (Danel et al, 2001).
  • Neurotoxicity from Gyromitra typically resolves over a week with effective seizure management, though fatalities can occur .
  • A small minority of patients who ingest Amanita mushrooms develop hepatoxicity (~1%). However, about half of those who present with acute liver failure may require liver transplantation. (Karvellas et al, 2016)
  • Anticholinergic toxicity usually resolves without sequelae, however deaths have occurred (Pauli and Foote, 2005)


  • Don’t collect and eat wild mushrooms!


  • The Emperor Claudius is thought to have been murdered by his wife Agrippina with the aid of poisonous mushrooms.
  • The German composer Johan Schubert died from poisonous mushrooms but remained adamant they were edible until the end.

  • Bedry R, Baudrimont I, Deffieux G, Creppy EE, Pomies JP, Ragnaud JM, Dupon M, Neau D, Gabinski C, De Witte S, Chapalain JC, Godeau P, Beylot J. Wild-mushroom intoxication as a cause of rhabdomyolysis. N Engl J Med. 2001 Sep 13;345(11):798-802. PMID: 11556299.
  • Danel VC, Saviuc PF, Garon D. Main features of Cortinarius spp. poisoning: a literature review. Toxicon. 2001 Jul;39(7):1053-60. doi: 10.1016/s0041-0101(00)00248-8. PMID: 11223095.
  • Diaz JH. Syndromic diagnosis and management of confirmed mushroom poisonings. Crit Care Med. 2005 Feb;33(2):427-36. PMID: 15699849.
  • Gawlikowski T, Romek M, Satora L. Edible mushroom-related poisoning: A study on circumstances of mushroom collection, transport, and storage. Hum Exp Toxicol. 2015 Jul;34(7):718-24. doi: 10.1177/0960327114557901. Epub 2014 Nov 4. PMID: 25378095.
  • Karvellas CJ, Tillman H, Leung AA, Lee WM, Schilsky ML, Hameed B, Stravitz RT, McGuire BM, Fix OK; United States Acute Liver Failure Study Group. Acute liver injury and acute liver failure from mushroom poisoning in North America. Liver Int. 2016 Jul;36(7):1043-50. doi: 10.1111/liv.13080. Epub 2016 Mar 4. PMID: 26837055.
  • Lima AD, Costa Fortes R, Carvalho Garbi Novaes MR, Percário S. Poisonous mushrooms: a review of the most common intoxications. Nutr Hosp. 2012 Mar-Apr;27(2):402-8. PMID: 22732961.
  • Pauli JL, Foot CL. Fatal muscarinic syndrome after eating wild mushrooms. Med J Aust. 2005 Mar 21;182(6):294-5. doi: 10.5694/j.1326-5377.2005.tb06705.x. PMID: 15777146.
  • Roberts DM, Hall MJ, Falkland MM, Strasser SI, Buckley NA. Amanita phalloides poisoning and treatment with silibinin in the Australian Capital Territory and New South Wales. Med J Aust. 2013 Jan 21;198(1):43-7. PMID: 23330770.

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Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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