Mushroom poisoning
Other namesMycetism, mycetismus
Amanita phalloides accounts for the majority of fatal mushroom poisonings worldwide.
SpecialtyEmergency medicine, toxicology

Mushroom poisoning is poisoning resulting from the ingestion of mushrooms that contain toxic substances. Its symptoms can vary from slight gastrointestinal discomfort to death in about 10 days. Mushroom toxins are secondary metabolites produced by the fungus.

Mushroom poisoning is usually the result of ingestion of wild mushrooms after misidentification of a toxic mushroom as an edible species. The most common reason for this misidentification is a close resemblance in terms of color and general morphology of the toxic mushrooms species with edible species. To prevent mushroom poisoning, mushroom gatherers familiarize themselves with the mushrooms they intend to collect, as well as with any similar-looking toxic species. The safety of eating wild mushrooms may depend on methods of preparation for cooking.

Signs and symptoms

See also: Category:Mycotoxins

Poisonous mushrooms contain a variety of different toxins that can differ markedly in toxicity. Symptoms of mushroom poisoning may vary from gastric upset to organ failure resulting in death. Serious symptoms do not always occur immediately after eating, often not until the toxin attacks the kidney or liver, sometimes days or weeks later.[1]

The most common consequence of mushroom poisoning is simply gastrointestinal upset. Most "poisonous" mushrooms contain gastrointestinal irritants that cause vomiting and diarrhea (sometimes requiring hospitalization), but usually no long-term damage. However, there are a number of recognized mushroom toxins with specific, and sometimes deadly, effects:

Toxin Toxicity Effects
Alpha-Amanitin Deadly Causes often fatal liver damage 1–3 days after ingestion. The principal toxin in the death cap.
Phallotoxin Non-lethal Causes extreme gastrointestinal upset. Found in various mushrooms.
Orellanine Deadly Redox cycler similar to paraquat. Causes kidney failure within three weeks after ingestion. Principal toxin in genus Cortinarius.
Muscarine Potentially deadly Causes SLUDGE syndrome. Found in various mushrooms. Antidote is atropine
Monomethylhydrazine (MMH) Deadly Causes brain damage, seizures, gastrointestinal upset, and hemolysis. Metabolic poison. Principal toxin in genus Gyromitra. Antidote is large doses of intravenous pyridoxine hydrochloride[2]
Coprine Non-lethal Causes illness when consumed with alcohol. Principal toxin in genus Coprinus.
Ibotenic acid Potentially deadly Excitotoxin. Principal toxin in Amanita muscaria, A. pantherina, and A. gemmata.
Muscimol Potentially deadly Causes CNS depression and hallucinations. Principal toxin in Amanita muscaria, A. pantherina, and A. gemmata.
Arabitol Non-lethal Causes diarrhea in some people.
Bolesatine Non-lethal Causes gastrointestinal irritation, vomiting, nausea.
Ergotamine Deadly Affects the vascular system and can lead to loss of limbs and/or cardiac arrest. Found in genus Claviceps.

The period between ingestion and the onset of symptoms varies dramatically between toxins, some taking days to show symptoms identifiable as mushroom poisoning.


New species of fungi are continuing to be discovered, with an estimated number of 800 new species registered annually. This, added to the fact that many investigations have recently reclassified some species of mushrooms from edible to poisonous has made older classifications insufficient at describing what now is known about the different species of fungi that are harmful to humans. Thus, contrary to what older registers state, it is now thought that of the approximately 100,000 known fungi species found worldwide, about 100 of them are poisonous to humans.[15] However, by far the majority of mushroom poisonings are not fatal,[16] and the majority of fatal poisonings are attributable to the Amanita phalloides mushroom.[17]

Amanita spp., immature, possibly poisonous, Amanita mushrooms.
Edible shaggy mane Coprinus comatus mushrooms.

A majority of these cases are due to mistaken identity.[18] This is a common occurrence with A. phalloides in particular, due to its resemblance to the Asian paddy-straw mushroom, Volvariella volvacea. Both are light-colored and covered with a universal veil when young.[citation needed]

Amanitas can be mistaken for other species, as well, in particular when immature. On at least one occasion[19] they have been mistaken for Coprinus comatus. In this case, the victim had some limited experience in identifying mushrooms, but did not take the time to correctly identify these particular mushrooms until after he began to experience symptoms of mushroom poisoning.[citation needed]

Amanitas, two examples of immature Amanitas, one deadly and one edible.
Puffball, an edible puffball mushroom, which closely resembles the immature Amanitas.

The author of Mushrooms Demystified, David Arora[5] cautions puffball-hunters to beware of Amanita "eggs", which are Amanitas still entirely encased in their universal veil. Amanitas at this stage are difficult to distinguish from puffballs. Foragers are encouraged to always cut the fruiting bodies of suspected puffballs in half, as this will reveal the outline of a developing Amanita should it be present within the structure.

A majority of mushroom poisonings, in general, are the result of small children, especially toddlers in the "grazing" stage, ingesting mushrooms found on the lawn. While this can happen with any mushroom, Chlorophyllum molybdites is often implicated due to its preference for growing in lawns. C. molybdites causes severe gastrointestinal upset but is not considered deadly poisonous.

A few poisonings are the result of misidentification while attempting to collect hallucinogenic mushrooms for recreational use.[20] In 1981, one fatality and two hospitalizations occurred following consumption of Galerina marginata, mistaken for a Psilocybe species.[21] Galerina and Psilocybe species are both small, brown, and sticky, and can be found growing together. However, Galerina contains amatoxins, the same poison found in the deadly Amanita species. Another case reports kidney failure following ingestion of Cortinarius orellanus,[22] a mushroom containing orellanine.

It is natural that accidental ingestion of hallucinogenic species also occurs, but is rarely harmful when ingested in small quantities. Cases of serious toxicity have been reported in small children.[13] Amanita pantherina, while containing the same hallucinogens as Amanita muscaria (e.g., ibotenic acid and muscimol), has been more commonly associated with severe gastrointestinal upset than its better-known counterpart.[5]

Jack-O-Lantern, a poisonous mushroom sometimes mistaken for a chanterelle.
Chanterelle, edible.

Although usually not fatal, Omphalotus spp., "Jack-o-lantern mushrooms", are another cause of sometimes significant toxicity.[5] They are sometimes mistaken for chanterelles. Both are bright-orange and fruit at the same time of year, although Omphalotus grows on wood and has true gills rather than the veins of a Cantharellus. They contain toxins known as illudins, which causes gastrointestinal symptoms.

Bioluminescent species are generally inedible and often mildly toxic.[citation needed]

Clitocybe dealbata, which is occasionally mistaken for an oyster mushroom or other edible species contains muscarine.

Toxicities can also occur with collection of morels. Even true morels, if eaten raw, will cause gastrointestinal upset. Typically, morels are thoroughly cooked before eating. Verpa bohemica, although referred to as "thimble morels" or "early morels" by some, have caused toxic effects in some individuals.[12] Gyromitra spp., "false morels", are deadly poisonous if eaten raw. They contain a toxin called gyromitrin, which can cause neurotoxicity, gastrointestinal toxicity, and destruction of the blood cells.[4] The Finns consume Gyromitra esculenta after parboiling, but this may not render the mushroom entirely safe, resulting in its being called the "fugu of the Finnish cuisine".

A more unusual toxin is coprine, a disulfiram-like compound that is harmless unless ingested within a few days of ingesting alcohol. It inhibits aldehyde dehydrogenase, an enzyme required for breaking down alcohol. Thus, the symptoms of toxicity are similar to being hung over—flushing, headache, nausea, palpitations, and, in severe cases, trouble breathing. Coprinus species, including Coprinopsis atramentaria, contain coprine. Coprinus comatus does not,[23] but it is best to avoid mixing alcohol with other members of this genus.

Recently,[when?] poisonings have also been associated with Amanita smithiana. These poisonings may be due to orellanine, but the onset of symptoms occurs in 4 to 11 hours, which is much quicker than the 3 to 20 days normally associated with orellanine.[24]

Paxillus involutus is also inedible when raw, but is eaten in Europe after pickling or parboiling. However, after the death of the German mycologist Dr. Julius Schäffer, it was discovered that the mushroom contains a toxin that can stimulate the immune system to attack its red blood cells. This reaction is rare but can occur even after safely eating the mushroom for many years.[25] Similarly, Tricholoma equestre was widely considered edible and good, until it was connected with rare cases of rhabdomyolysis.[26]

In the fall of 2004, thirteen deaths were associated with consumption of Pleurocybella porrigens or "angel's wings".[27] In general, these mushrooms are considered edible. All the victims died of an acute brain disorder, and all had pre-existing kidney disease. The exact cause of the toxicity was not known at this time and the deaths cannot be definitively attributed to mushroom consumption.

However, mushroom poisoning is not always due to mistaken identity. For example, the highly toxic ergot Claviceps purpurea, which grows on rye, is sometimes ground up with rye, unnoticed, and later consumed. This can cause devastating, even fatal effects, which is called ergotism.

Cases of idiosyncratic or unusual reactions to fungi can also occur. Some are probably due to allergy, others to some other kind of sensitivity. It is not uncommon for a person to experience gastrointestinal upset associated with one particular mushroom species or genus.[27]

Some mushrooms might concentrate toxins from their growth substrate, such as Chicken of the Woods growing on yew trees.[28]

Poisonous mushrooms

See also: List of deadly fungus species and List of poisonous fungus species

Of the most lethal mushrooms, five—the death cap (A. phalloides), the three destroying angels (A. virosa, A. bisporigera, and A. ocreata), and the fool's mushroom (A. verna)—belong to the genus Amanita, and two more—the deadly webcap (C. rubellus), and the fool's webcap (C. orellanus)—are from the genus Cortinarius. Several species of Galerina, Lepiota, and Conocybe also contain lethal amounts of amatoxins. Deadly species are listed in the List of deadly fungi.[citation needed]

The following species may cause great discomfort, sometimes requiring hospitalization, but are not considered deadly.

Prognosis and treatment

Some mushrooms contain less toxic compounds and, therefore, are not severely poisonous. Poisonings by these mushrooms may respond well to treatment. However, certain types of mushrooms contain very potent toxins and are very poisonous; so even if symptoms are treated promptly, mortality is high. With some toxins, death can occur in a week or a few days. Although a liver or kidney transplant may save some patients with complete organ failure, in many cases there are no organs available. Patients hospitalized and given aggressive support therapy almost immediately after ingestion of amanitin-containing mushrooms have a mortality rate of only 10%, whereas those admitted 60 or more hours after ingestion have a 50–90% mortality rate.[31] In the United States, mushroom poisoning kills an average of about 3 people a year.[32] According to National Poison Data System (NPDS) annual reports published by America's Poison Centers, the average number of deaths occurring over a ten year period (2012-2020) sits right at 3 a year.[33] In 2012, 4 out of the 7 total deaths that occurred that year, were attributed to a single event where a "housekeeper at a Board and Care Home for elderly dementia patients collected and cooked wild (Amanita) mushrooms into a sauce that she consumed with six residents of the home."[34].[35] Over 1,300 emergency room visits in the United States were attributed to poisonous mushroom ingestion in 2016, with about 9% of patients experiencing a serious adverse outcome. [36]

Society and culture

Folk traditions

Many folk traditions concern the defining features of poisonous mushrooms.[37][38] However, there are no general identifiers for poisonous mushrooms, so such traditions are unreliable. Guidelines to identify particular mushrooms exist, and will serve only if one knows which mushrooms are toxic.[citation needed]

Examples of erroneous folklore "rules" include:

Notable cases

See also


  1. ^ "Nеgativе Effеcts of Portabеlla Mushrooms". Karnodhar English. 2023-07-27. Retrieved 2023-07-27.
  2. ^ Wright AV, Niskanen A, Pyysalo H, Korpela H (1981). "Amelioration of toxic effects of ethylidene gyromitrin (false morel poison) with pyridoxine chloride". Journal of Food Safety. 3 (3): 199–203. doi:10.1111/j.1745-4565.1981.tb00422.x.
  3. ^ a b c d Ford, Marsha; Kathleen A. Delaney; Louis Ling; Timothy Erickson (2001). Clinical Toxicology. USA: WB Saunders. pp. ch115. ISBN 978-0-7216-5485-0.
  4. ^ a b c Gyromitra Mushroom Toxicity at eMedicine
  5. ^ a b c d e f g h i j k l m n o Arora, David (1986). Mushrooms Demystified. California, USA: Ten Speed Press. pp. 679. ISBN 978-0-89815-169-5.
  6. ^ Benjamin DR. "Amatoxin syndrome": 198–214. ((cite journal)): Cite journal requires |journal= (help) in: Mushrooms: poisons and panaceas – a handbook for naturalists, mycologists and physicians. New York: WH Freeman and Company. 1995.
  7. ^ Saller R, Brignoli R, Melzer J, Meier R (February 2008). "An updated systematic review with meta-analysis for the clinical evidence of silymarin" (PDF). Forsch Komplementärmed. 15 (1): 9–20. doi:10.1159/000113648. PMID 18334810. S2CID 23468345.
  8. ^ Hruby K, Csomos G, Fuhrmann M, Thaler H (April 1983). "Chemotherapy of Amanita phalloides poisoning with intravenous silibinin". Hum Toxicol. 2 (2): 183–95. doi:10.1177/096032718300200203. PMID 6862461. S2CID 19805371.
  9. ^ Orellanine Mushroom Toxicity at eMedicine
  10. ^ Veronika Pelizzari; Elisabeth Feifel; Manuela M. Rohrmoser; Gerhard Gstraunthaler; Meinhard Moser (July 1994). "Partial Purification and Characterization of a Toxic Component of Amanita smithiana". Mycologia. Mycological Society of America. 86 (4): 555–60. doi:10.2307/3760749. JSTOR 3760749.
  11. ^ Mushroom Toxicity at eMedicine
  12. ^ a b "IA #25-02 – 9/19/96, REVISION OF IMPORT ALERT #25-02, "**DETENTION WITHOUT PHYSICAL EXAMINATION** OF MOREL MUSHROOMS DUE TO ADULTERATION AND SUBSTITUTION", ATTACHMENT A – 2 February 2006". FDA. 2006-02-02. Archived from the original on 2008-04-16. Retrieved 2008-08-04.
  13. ^ a b c Hallucinogenic Mushroom Toxicity at eMedicine
  14. ^ Lindgren, Jan (May 2003). "Theory for why "edible" mushrooms make some people sick" (PDF newsletter). Spore Prints. Puget Sound Mycological Society. Retrieved 2008-08-05.
  15. ^ Graeme, Kimberlie A. (June 2014). "Mycetism: A Review of the Recent Literature". Journal of Medical Toxicology. 10 (2): 173–189. doi:10.1007/s13181-013-0355-2. PMC 4057534. PMID 24573533.
  16. ^ Gussow L (November 2000). "The optimal management of mushroom poisoning remains undetermined". West. J. Med. 173 (5): 317–8. doi:10.1136/ewjm.173.5.317. PMC 1071150. PMID 11069865.
  17. ^ Centres for Disease Control and Prevention (CDC) (June 1997). "Amanita phalloides mushroom poisoning – Northern California, January 1997". MMWR Morb. Mortal. Wkly. Rep. 46 (22): 489–92. PMID 9194398.
  18. ^ a b Centers for Disease Control (CDC) (June 4, 1982). "Mushroom Poisoning among Laotian Refugees – 1981". MMWR. USA: CDC. 31 (21): 287–8. PMID 6808348. Retrieved 2008-08-04.
  19. ^ Eschelman, Richard (2006). "I survived the "Destroying Angel"" (blog). Cornell. Retrieved 2008-08-04.
  20. ^ Halpern, John; R. Andrew Sewell (December 2005). "Hallucinogenic botanicals of America: A growing need for focused drug education and research". Life Sciences. USA. 78 (5): 519–526. doi:10.1016/j.lfs.2005.09.005. PMID 16188280.
  21. ^ "Death due to Galerina". Seattle Post-Intelligencer. 28 December 1981.
  22. ^ Calviño, Jesus; Romero, Rafael; Pintos, Elena; Novoa, Daniel; Güimil, Dolores; Cordal, Teresa; Mardaras, Javier; Arcocha, Victor; Lens, XoseM.; Sanchez-Guisande, Domingo (1998). "Voluntary Ingestion of Cortinarius Mushrooms Leading to Chronic Interstitial Nephritis". American Journal of Nephrology. 18 (6): 565–569. doi:10.1159/000013410. PMID 9845839. S2CID 2175833.
  23. ^ Disulfiramlike Mushroom Toxicity at eMedicine
  24. ^ "Mushroom Poisoning Syndromes". NAMA. 2003. Archived from the original on 2008-03-29. Retrieved 2008-08-13.
  25. ^ a b Bresinsky A, Besl H (1990). A Colour Atlas of Poisonous Fungi. Wolfe Publishing. pp. 126–9. ISBN 0-7234-1576-5.
  26. ^ Chodorowski Z, Waldman W, Sein Anand J (2002). "Acute poisoning with Tricholoma equestre". Prz. Lek. 59 (4–5): 386–7. PMID 12184017.
  27. ^ a b Beug, Michael (2004). "Mushroom Poisonings Reported in 2004". North American Mycological Association Toxicology Committee. Archived from the original on 2008-07-04. Retrieved 2008-08-04.
  28. ^ "How to tell the difference between poisonous and edible mushrooms". Wildfood UK. 2014-04-29. Retrieved 15 October 2018.
  29. ^ Gover, DW (2005-04-24). "FUNGAL TOXINS AND THEIR PHYSIOLOGICAL EFFECTS". Archived from the original on 2008-07-19. Retrieved 2008-08-13.
  30. ^ Suzuki, Kumiko; Fujimoto, Haruhiro; Yamazaki, Mikio (1983). "The toxic principles of Naematoloma fasciculare". Chemical & Pharmaceutical Bulletin. 31 (6): 2176–2178. doi:10.1248/cpb.31.2176. PMID 6685576.
  31. ^ "Mushroom Toxins". FDA Bad Bug Book. FDA. 9 January 2008.
  32. ^ "Plant and Mushroom Poisoning Statistics Summary". Eat The Planet. 2018-01-04. Retrieved 2023-06-07.((cite web)): CS1 maint: url-status (link)
  33. ^ "ANNUAL REPORTS". America's Poison Centers. 2022. Retrieved 2023-06-07.((cite web)): CS1 maint: url-status (link)
  34. ^ Mowry, James B; Spyker, Daniel A; Cantilena Jr., Louis R; Bailey, J Elise; Ford, Marsha (23 December 2013). "2012 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 30th Annual Report" (PDF). Clinical Toxicology. 51 (10): 1211. doi:10.3109/15563650.2013.863906. PMID 24359283. S2CID 43129572. Retrieved 7 June 2023.
  35. ^ "Foraging Fatality Statistics 2016 (Please Share)". Eat The Planet. 2018-01-04. Retrieved 2021-05-11.((cite web)): CS1 maint: url-status (link)
  36. ^ Gold JA; Kiernan E; Yeh M; Jackson BR; Benedict K (March 12, 2021). "Health Care Utilization and Outcomes Associated with Accidental Poisonous Mushroom Ingestions — United States, 2016–2018". MMWR. USA: CDC. 70 (10): 337–341. PMC 7951822. PMID 33705365. Retrieved 2021-06-05.
  37. ^ "California Poison Action Line: Mushrooms". Archived from the original on 2008-02-10. Retrieved 2008-02-18.
  38. ^ Ian Robert Hall (2003). Edible and Poisonous Mushrooms of the World. Timber Press. p. 103. ISBN 0-88192-586-1.
  39. ^ "Woman died of mushroom poisoning". BBC News. 2010-03-18.
  40. ^ Pitel, Laura (2010-03-19). "Amphon Tuckey died after eating death cap mushrooms picked at botanic gardens". The Times. London.
  41. ^ Stamets, Paul (2000). Growing gourmet and medicinal mushrooms. Random House, Inc. p. 1. ISBN 978-1-58008-175-7.
  42. ^ Wasson, Gordon (1986). Persephone's Quest: Entheogens and the Origins of Religion. privately published. p. 131. ISBN 0-300-05266-9.
  43. ^ Marmion, V.J.; Wiedemann, T.E.J. (May 2002). "The death of Claudius". J R Soc Med. 95 (5): 260–1. doi:10.1177/014107680209500515. PMC 1279685. PMID 11983773.
  44. ^ "Delicious or deadly? You pick". 2 September 2008.
  45. ^ Evans, N; Hamilton, A; Bello-Villalba, M. J; Bingham, C (2012). "Irreversible renal damage from accidental mushroom poisoning". BMJ. 345: e5262. doi:10.1136/bmj.e5262. PMID 22885396.
  46. ^ The Slightly Different Temperature Scale. (in German). Retrieved 1 June 2023
  47. ^ Schaechter, Moselio (1998). In the Company of Mushrooms: A Biologist's Tale. Harvard University Press. pp. 15, 18. ISBN 9780674445550.