Mushroom Poisoning

Essentials of Diagnosis

• Vomiting, diarrhea, and abdominal cramps after ingestion of many different toxic mushrooms

• Amatoxin-type

  • Delayed-onset severe gastroenteritis, followed by severe hepatic injury

General Considerations

• There are thousands of toxic mushroom species

• Ingestion of even a portion of an amatoxin-containing mushroom may be sufficient to cause death

• Cooking amatoxin-type cyclopeptides does not prevent the poisoning

Symptoms and Signs

• Amatoxin-type cyclopeptides (Amanita phalloides, Amanita ocreata, Amanita verna, Amanita virosa, and Galerina species)

  • After a latent interval of 8–12 h, severe abdominal cramps and vomiting begin and progress to profuse diarrhea

  • Acute kidney injury, hepatic necrosis, and hepatic encephalopathy, occur 1–2 days after onset

• Gyromitrin type (Gyromitra and Helvella species)

  • Toxicity is more common following ingestion of uncooked mushrooms

  • Vomiting, diarrhea, hepatic necrosis, convulsions, coma, and hemolysis may occur after a latent period of 8–12 h

• Muscarinic type (Inocybe and Clitocybe species)

  • Vomiting, diarrhea, bradycardia, hypotension, salivation, miosis, bronchospasm, and lacrimation occur shortly after ingestion

  • Cardiac arrhythmias may occur

• Anticholinergic type (Amanita muscaria, Amanita pantherina)

  • Excitement

  • Delirium

  • Flushed skin

  • Dilated pupils

  • Muscular jerking tremors

• Gastrointestinal irritant type (Boletus, Cantharellus)

  • Nausea, vomiting, and diarrhea occur shortly after ingestion

• Disulfiram type (Coprinus species)

  • Disulfiram-like sensitivity to alcohol may persist for several days

  • Toxicity is characterized by flushing, hypotension, and vomiting after coingestion of alcohol

• Hallucinogenic (Psilocybe and Panaeolus species)

  • Mydriasis, nausea and vomiting, and intense visual hallucinations occur 1–2 h after ingestion

• Cortinarius orellanus

  • May cause acute kidney injury due to tubulointerstitial nephritis

Differential Diagnosis

• Differential diagnosis of Amatoxin-type mushroom poisoning

  • Acetaminophen poisoning

  • Acute viral hepatitis

Diagnostic Procedures

• There are no readily available laboratory tests for mushroom toxins

• Local mycologist may help identify suspect fungi

• Amatoxin-type mushrooms

  • Typical delay of 8–12 hours before gastrointestinal symptoms occur

  • Hepatic transaminases elevated after 24 hours

  • Necrosis of the liver, massive and acute

  • Metabolic acidosis, hypoglycemia, elevated ammonia suggest severe hepatic failure

Medications

EMERGENCY MEASURES

• Administer activated charcoal (60–100 g orally or via gastric tube, mixed in aqueous slurry) for any recent ingestion

• Give intravenous fluids to replace losses from vomiting and diarrhea

• Monitor central venous pressure, urinary output, and kidney function tests to help guide volume replacement

• After the onset of symptoms, efforts to remove the toxic agent are probably useless, especially in cases of amatoxin or gyromitrin poisoning, in which there is usually a delay of 12 h or more before symptoms occur

SPECIFIC MEASURES

• Amatoxin-type cyclopeptides

  • Aggressive fluid replacement for diarrhea and intensive supportive care for hepatic failure (including liver transplant if needed) are the mainstays of treatment

  • Silymarin (silibinin)

    • Often used in Europe

    • Currently only commercially available in the United States as a nutritional supplement given orally

  • Liver transplant may be the only hope for survival in gravely ill patients—contact a liver transplant center early

• Gyromitrin type: Give pyridoxine, 25 mg/kg intravenously

• Muscarinic type

  • Give atropine, 0.005–0.01 mg/kg intravenously

  • Repeat as needed

• Anticholinergic type

  • Physostigmine, 0.5–1.0 mg intravenously

  • May calm extreme agitation and reverse peripheral anticholinergic manifestations

  • However, may also cause bradycardia, asystole, and seizures

  • Alternately, use lorazepam, 1–2 mg intravenously

• Gastrointestinal irritant type: Treat with antiemetics and intravenous or oral fluid

• Disulfiram type: Avoid alcohol and treat acetaldehyde reaction with fluids and supine position

• Hallucinogenic type

  • Provide a quiet, supportive atmosphere

  • Diazepam or haloperidol may be used for sedation

• Cortinarius

  • Provide supportive care

  • Hemodialysis as needed for acute kidney injury

Prognosis

• Fatalities are rare with

  • Muscarinic type

  • Anticholingeric type

  • Gastrointestinal irritant type

  • Hallucinogenic mushrooms

When to Refer

• Liver transplant may be necessary, particularly for amatoxin-type cyclopeptides

• Contact a transplant center early