There are thousands of mushroom species that cause a variety of toxic effects. The most dangerous species of mushrooms are Amanita phalloides and related species, which contain potent cytotoxins (amatoxins). Ingestion of even a portion of one amatoxin-containing mushroom may be sufficient to cause death.
The characteristic pathologic finding in fatalities from amatoxin-containing mushroom poisoning is acute massive necrosis of the liver.
Amatoxin-containing mushrooms typically cause a delayed onset (8–12 hours after ingestion) of severe abdominal cramps, vomiting, and profuse diarrhea, followed in 1–2 days by acute kidney injury, hepatic necrosis, and hepatic encephalopathy. Cooking the mushrooms does not prevent poisoning.
Monomethylhydrazine poisoning (Gyromitra and Helvella species) is more common following ingestion of uncooked mushrooms, as the toxin is water-soluble. Vomiting, diarrhea, hepatic necrosis, convulsions, coma, and hemolysis may occur after a latent period of 8–12 hours.
The clinical effects of these and other mushrooms are described in eTable 38–2.
eTable 38–2.Poisonous mushrooms (listed in alphabetical order). ||Download (.pdf) eTable 38–2. Poisonous mushrooms (listed in alphabetical order).
|Toxin ||Genus ||Symptoms and Signs ||Onset ||Treatment |
|Amanitin ||Amanita (A ocreata, A phalloides, A verna, A virosa) ||Severe gastroenteritis followed by delayed hepatic failure and acute kidney injury after 48–72 hours ||6–24 hours ||Supportive. Correct dehydration. Give repeated doses of activated charcoal orally. Consider intravenous silibinin (Legalon-SIL). |
|Coprine ||Coprinus ||Disulfiram-like effect occurs with ingestion of ethanol ||30–60 minutes ||Supportive. Abstain from ethanol for 3–4 days. |
|Gastrointestinal irritants ||Many species ||Nausea and vomiting, diarrhea ||1/2–2 hours ||Supportive. Correct dehydration. |
|Ibotenic acid, muscimol ||Amanita muscaria ("fly agaric") ||Anticholinergic (mydriasis, tachycardia, hyperpyrexia, delirium) ||30–60 minutes ||Supportive. Give physostigmine, 0.5–2 mg intravenously, for severe anticholinergic symptoms and signs. |
|Monomethyl-hydrazine ||Gyromitra ||Gastroenteritis; occasionally seizures, hemolysis, hepatic failure, and acute kidney injury ||6–12 hours ||Supportive. Correct dehydration. Pyridoxine, 2.5 mg/kg intravenously, may be helpful for seizures. |
|Muscarine ||Inocybe, Clitocybe ||Muscarinic (salivation, miosis, bradycardia, diarrhea) ||30–60 minutes ||Supportive. Give atropine, 0.5–2 mg intravenously, for severe cholinergic symptoms and signs. |
|Orellanine ||Cortinarius ||Nausea, vomiting; acute kidney injury after 1–3 weeks ||2–14 days ||Supportive. |
|Psilocybin ||Psilocybe ||Hallucinations ||15–30 minutes ||Supportive. |
(Inocybe and Clitocybe species.) Vomiting, diarrhea, bradycardia, hypotension, salivation, miosis, bronchospasm, and lacrimation occur shortly after ingestion. Cardiac arrhythmias may occur. Fatalities are rare.
(Eg, Amanita muscaria, Amanita pantherina.) This type causes a variety of symptoms that may be atropine-like, including excitement, delirium, flushed skin, dilated pupils, and muscular jerking tremors, beginning 1–2 hours after ingestion. Fatalities are rare.
3. Gastrointestinal irritant type
(Eg, Boletus, Cantharellus.) Nausea, vomiting, and diarrhea occur shortly after ingestion. Fatalities are rare.