Biphasic amatoxin poisoning — 6–24h latent, GI phase, deceptive false recovery, hepatorenal failure day 3–5. What ER teams do, and when to call poison control.
Amanitin (alpha-amanitin, beta-amanitin, gamma-amanitin) is the group of cyclic octapeptide toxins produced by Amanita phalloides ("death cap"), Amanita virosa ("destroying angel"), Galerina marginata ("deadly Galerina"), and several Lepiota species. These toxins cause acute liver failure that begins silently and can kill within a week without treatment. Alpha- amanitin binds RNA polymerase II, halting messenger-RNA production. Cells with high protein turnover — liver hepatocytes, then kidney tubular cells — die over 48 to 96 hours.
No symptoms. Patients feel completely normal. Amanitin has been absorbed and is already inside hepatocytes binding RNA polymerase II. This is the window where treatment is easiest and most effective — and the window when most people incorrectly assume they are safe.
Sudden violent vomiting. Profuse, cholera-like watery diarrhoea. Abdominal cramps. Rapid dehydration and electrolyte loss. The American College of Emergency Physicians specifically flags delayed-onset (past 6 hours) GI symptoms after a mushroom meal as one of the presentations that should raise amatoxin suspicion.
GI symptoms subside. Patients feel much better and frequently request discharge. Liver enzymes (AST, ALT), bilirubin, and INR are climbing during this window; hepatocyte death continues silently. Premature discharge in this window is a well-documented cause of preventable death.
Jaundice, coagulopathy, hypoglycaemia, encephalopathy, acute liver failure. Renal failure follows in many patients. Survival depends on how early supportive care started and how quickly the patient reaches a hospital with a liver-transplant service.
Amanita bisporigera is a deadly poisonous mushroom known as the eastern North American destroying angel. It contains cyclic octapeptides called amanitins, the same toxin family found in the death cap, Amanita phalloides. Ingestion triggers the delayed poisoning timeline described above, progressing from severe gastrointestinal illness to acute liver and kidney failure.
This fungus grows in eastern North American woodlands among hardwoods and conifers. It is pure white. The stem carries a delicate skirt and a sac-like volva that often sits entirely below the soil line.
Foragers who cut the stem above ground miss this buried base and can confuse the mushroom with edible button mushrooms, meadow mushrooms, or young puffballs. The name bisporigera refers to basidia that bear two spores, which is a microscopic feature that nobody can check in the field. Related destroying angels include Amanita ocreata in western North America and Amanita virosa in Europe.
Amanita bisporigera contains no psilocybin, carries no psychoactive properties, and is not scheduled under the Controlled Substances Act. Wild mushroom pickers and readers reviewing psilocybin mushroom identification safety encounter these toxic species in the same regions, much like Galerina marginata. Never consume any wild mushroom on the strength of a web description.
If you suspect someone ingested any part of a destroying angel, call United States Poison Help at 1-800-222-1222 immediately without waiting for symptoms to emerge. Bring an intact physical specimen or clear photographs of the base and cap to the hospital for clinical identification.
The death cap is Amanita phalloides, an amatoxin mushroom in the Phalloideae section of the Amanita family. A 2017 report from the Centers for Disease Control and Prevention (CDC) says it is responsible for most deaths following ingestion of foraged mushrooms worldwide. Its amatoxins injure cells by halting protein synthesis. It contains no psilocybin, has no psychoactive effect, and is not scheduled under the Controlled Substances Act.
The CDC report covers 14 Amanita phalloides poisonings that the California Poison Control System identified in December 2016. All 14 people had eaten foraged mushrooms in the greater San Francisco Bay Area. Bay Area Mycological Society members had warned the poison system on November 28, 2016 of an unusually large bloom after heavy rain and warm weather, and in the few years before, the system received only a few mushroom poisoning reports per year.
All 14 patients developed gastrointestinal illness leading to dehydration and liver toxicity, and three received liver transplants. All recovered, though one patient, a child, was left with permanent neurologic impairment. Treatment included aggressive intravenous fluids and intravenous silibinin, given under a clinical trial in the US at the time.
The first patient cooked and ate one mushroom and developed nausea, vomiting and diarrhea about 10 hours later, so cooking did not make it safe. Another patient was sent home from an emergency department with a gastroenteritis diagnosis, returned the next day sicker, and ultimately needed a liver transplant. The CDC notes that these symptoms can mimic viral gastroenteritis while the illness slowly progresses to potentially fatal liver toxicity.
The CDC recommends that a trained mycologist evaluate wild-picked mushrooms before anyone eats them, and it strongly discourages inexperienced foragers from eating any wild mushrooms. A description on a web page, including this one, is not an identification. For related foraging safety information, see our guide to psilocybin mushroom identification safety. After any suspected ingestion, call Poison Help at 1-800-222-1222 right away without waiting for symptoms, and keep any leftover mushroom or photos.
Alpha-amanitin is heat-stable, acid-stable, freeze-stable, and dry- stable. Cooking does not destroy it. Drying does not destroy it. Freezing does not destroy it. Tea preparation does not destroy it. There is no home preparation that reduces the risk. It also does not irritate the mouth or stomach on contact — patients absorb the toxin without any warning taste or nausea. By the time symptoms appear, hours of enterohepatic recirculation have re-delivered the toxin to the liver repeatedly.
There is no single approved antidote for amanitin poisoning. Standard care per clinical toxicology references and ACEP guidance combines several interventions:
| Intervention | Purpose | When used |
|---|---|---|
| Aggressive IV fluid resuscitation | Correct GI-loss dehydration and support renal perfusion | From ED arrival |
| Multi-dose activated charcoal | Interrupt enterohepatic recirculation of amanitin | If patient presents early or GI still active |
| Silibinin (Legalon) | Blocks hepatocyte uptake of amanitin (OATP1B3 inhibition) | Available through expanded-access programme in US; standard care in EU |
| N-acetylcysteine | Antioxidant and hepatic glutathione support | Standard adjunct |
| Serial LFTs, INR, glucose | Track hepatocyte death and coagulopathy | Every 6–12 hours |
| Transfer to transplant centre | Access to King's College / Clichy criteria evaluation | If AST/ALT and INR trend worsening |
Silibinin (a purified milk thistle flavonolignan) is standard of care in much of the European Union and is accessible in the US through an expanded-access programme run by Mithridion / Legalon SIL via participating poison centres. If your hospital does not have silibinin on formulary, the poison centre call can find the nearest supply.
Call poison control before symptoms start. In the US that is 1-800-222-1222, free, 24 hours a day. The reason is time: interventions are dramatically more effective during the latent phase than after liver damage is established. A poison-centre toxicologist can also identify the closest silibinin supply and the closest transplant centre if the case worsens.
Outcomes vary widely with the amount ingested, patient age, and how quickly treatment starts. Modern series in centres with silibinin access report survival above 80% when treatment begins in the latent or early GI phase; historical series before silibinin and standardised supportive care reported mortality of 20–30%. Paediatric outcomes are generally worse because dose per kilogram is higher. See summaries in Ye and Liu (2018) and the NAMA Toxicology Committee reports.
Amanitin is a family of cyclic octapeptide toxins (alpha-, beta-, and gamma-amanitin) produced by several genera of mushrooms — Amanita, Galerina, and some Lepiota. It binds RNA polymerase II inside cells and stops protein synthesis. Liver and kidney cells are affected first.
Usually 6 to 24 hours. That long, silent delay is the single most dangerous feature of amatoxin poisoning. Symptoms starting within the first two hours after a mushroom meal usually indicate a different toxin (gastroenteric syndromes from other genera).
No single approved antidote. Silibinin (Legalon) blocks hepatocyte uptake of amanitin and is standard of care in the EU; it is accessible in the US through an expanded-access programme. N-acetylcysteine, aggressive IV fluids, and early transplant referral are combined with silibinin.
Yes, especially with early treatment. Modern series with silibinin access report survival above 80% when care starts during the latent or early GI phase. Delayed presentation, high dose, or paediatric cases have worse outcomes. Liver transplant is the last-resort option for fulminant hepatic failure.
Around day 2 after ingestion, the GI phase resolves and patients feel dramatically better. Liver enzymes and INR are climbing during this window while hepatocytes continue to die silently. Patients often try to leave hospital during false recovery. Discharging them here is a documented cause of preventable death.
No. Amanitin is heat-stable, acid-stable, freeze-stable, and dry- stable. Cooking, drying, tea preparation, and freezing do not reduce toxicity. This is the specific molecular property that makes amatoxin mushrooms so dangerous compared to other risky foods.
No. They are unrelated. Psilocybin is not systemically toxic in the way amanitin is; the risks are psychological and cardiovascular, not hepatic failure. Amanitin poisoning shows up in people who thought they had picked psilocybin mushrooms and picked Galerina marginata instead. That is why the two topics share this cluster of pages.
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