1. Skip to Menu
  2. Skip to Content
  3. Skip to Footer

Amanita Phalloides Mushroom Poisoning

Amanita phalloides, colloquially known as the “death cap,” belongs to the Phalloideae section of the Amanita family of mushrooms and is responsible for most deaths following ingestion of foraged mushrooms worldwide.

A. phalloides contains the alpha variety of amanitin, a cyclic octapeptide thought to be the primary agent of toxicity in humans. The amanitins are heat stable and are not inactivated by cooking. A lethal dose can be as low as 0.1 mg/kg, and a single mushroom can contain up to 15 mg. Once ingested, amatoxin is readily absorbed from the gastrointestinal tract into the portal circulation where it is taken up by hepatocytes. Amatoxin binds to DNA-dependent RNA polymerase (II) and inhibits protein synthesis, ultimately resulting in cell death.

The clinical course of amatoxin poisoning is described in three phases:

  • Delayed gastroenteritis with significant body fluid volume loss within 6 to 24 hours after ingestion
  • Symptomatic recovery within 24 to 36 hours after ingestion
  • Fulminant hepatic and multiorgan failure 3 to 5 days after ingestion.

Patients who are evaluated early in the course of their illness might be discharged home only to return later with indications of liver failure, contributing to the relatively high case fatality rate of 10% to 20%.

Liver enzymes begin to rise 24 to 36 hours after ingestion. Progressive liver disease results in elevated bilirubin, prothrombin time, and ammonia. Development of hepatorenal syndrome is accompanied by acidosis, hypoglycemia and renal failure. Vomiting and diarrhea cause electrolyte abnormalities. Analysis of specific mycotoxins is not usually available quickly enough to be clinically valuable.

Initial treatment includes early supportive care including aggressive fluid and electrolyte replacement. In the event of irreversible fulminant liver failure, liver transplant might be required. A variety of therapies including multidose activated charcoal, high-dose penicillin, N-acetylcysteine, cimetidine, biliary drainage, and octreotide have been attempted with no definitive evidence of efficacy.


  1. Wieland T, Wieland O. Chemistry and toxicology of the toxins of Amanita phalloides Pharmacol Rev 1959;11:87–107. PubMed
  2. Wieland T. The toxic peptides from Amanita mushrooms. Int J Pept Protein Res 1983;22:257–76.  CrossRef PubMed
  3. Olson KR, Pond SM, Seward J, Healey K, Woo OF, Becker CE. Amanita phalloides-type mushroom poisoning. West J Med 1982;137:282–9. PubMed
  4. Vo KT et al. Amanita phalloides Mushroom Poisonings – Northern California, December 2016, MMWR June 2, 2017;66:549-53
AddThis Social Bookmark Button

Stay Informed

Amazon Book

Our Sponsors

Login Form

Mobile Applications

iPad mini Horz Vert 300w

Get it for: iPhoneiPad

ClinLab Navigator Information

McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
© 2015 ClinLab Navigator, LLC.