NAMA Store >

Namyco Logo

2012 NAMA Toxicology Committee Report North American Mushroom Poisonings

Michael W. Beug, PhD, Chair NAMA Toxicology Committee
PO Box 116, Husum, WA 98623
email: beugm [at]


In 2012, 35 of the 100 human poisoning cases we have reports for involved amatoxins. The vast majority of the amatoxin cases involved ingestion of he death cap, Amanita phalloides. Other cases involved destroying angels, Amanita ocreataAmanita bisporigera and similar all-white Amanita species. There were three deaths in the United States from a single incident where elderly residents of a residential care facility were served soup made with deadly Amanita species. There were two deaths in two separate cases in Canada.

While we often learn of the majority of amatoxin cases, we only get a small sampling of other mushroom poisonings since they rarely involve death of the victim. Of the cases with symptoms severe enough for the individual to go to the hospital, over 14% were adverse reactions to hallucinogenic mushrooms, predominately Psilocybe species. Chlorophyllum molybdites accounted for 12% of this year’s cases. Adverse reactions to various Morchella species accounted for 10%.

We learned of 26 dogs and one horse poisoned by mushrooms, with 11 dog deaths, mostly from amatoxins. In two deaths, Inocybe species were implicated. In one death, two doses of atropine were administered to a dog who had consumed Amanita muscaria. Atropine markedly intensifies the effects of the toxins ibotenic acid and muscimol and so is contraindicated in such cases.

In 2012, there were once again many reports of amatoxin poisonings, both in humans (five deaths) and in dogs (six deaths from apparent amatoxins). For humans, two cases in Canada each involved one death and one case in the United States involved three deaths.

In the first Canadian case, the victim was an alcoholic. The victim was treated initially as a cardiac patient, but there was a rapid progression to multi-organ failure and death. A relative later found and discarded the remains of a cooked mushroom dish that was in the victim’s refrigerator. While no attempt was ever made to identify the mushrooms, the symptoms were consistent with amatoxin poisonings. In the second Canadian case, the mushrooms were identified post mortem as Amanita virosa. The man had a history of colitis and thus mushroom poisoning was discounted by his doctor. He was treated for his diarrhea and cramps and sent home. Two days later, he reported to the hospital with fulminant hepatic failure. He died 8 days after his mushroom meal. The poison center was never notified and best treatment practices for amatoxin poisoning were not employed.

All three deaths in the United States resulted from a single case in California where a caregiver at a residential care facility made a soup from mushrooms collected on the grounds. One elderly tenant had refused the dinner and was not ill, alerting investigators to the soup as the cause of the illnesses. The mushrooms were never positively identified, but descriptions by the caregiver implicate either Amanita phalloides or Amanita ocreata. The caregiver survived with aggressive rehydration therapy and use of injectable silymarin (Legalon®SIL). Three of the four elderly residents who consumed the soup succumbed. The first death occurred three days after the meal. A woman in her 90s recovered from the poisoning symptoms with use of aggressive rehydration alone but then died 20 days later due to other causes (Todd Mitchell, personal communication). Press accounts attributed her death to mushroom poisoning.

In five other cases in the United States (four in 2012 and one previously unreported case from 2011), at least 24 people consumed deadly Amanita species. After hospital admission, all were enrolled in the “Legalon®SIL; Mushroom Poisoning Clinical Study.” Following protocol, aggressive rehydration therapy was used in every case. The sickest individuals all received injectable silymarin and one individual, who had consumed a staggering quantity of Amanita phalloides, was treated using percutaneous cholecystostomy in addition to other therapies. All survived.

In a Connecticut case involving destroying angel mushrooms (Amanita cf bisporigera), all four family members survived. There were news reports of three Amanita phalloides cases in Ohio. One, involving at least a dozen people, happened in 2011, while two cases, each involving 4 people happened in 2012. In all three Ohio incidents and in the Connecticut incident, some individuals were sick enough to meet the criteria for treatment with injectable silymarin and so received injections of Legalon®SIL in addition to aggressive rehydration therapy.

On December 28, 2012, a California woman consumed approximately six Amanita phalloides mushrooms. By coincidence, when she reported to the hospital, Dr. Todd Mitchell was in the emergency room seeking treatment for his son who had dislocated his pinkie at volleyball practice (Todd Mitchell, personal communication). Dr. Mitchell is principal investigator for the drug interventional trial of injectable silymarin (Legalon®SIL) to treat amatoxin poisoning. In addition to aggressive rehydration therapy, the woman was treated with injectable silymarin. An interventional radiologist performed a percutaneous cholecystostomy. The woman was released from the hospital five days later after making a complete recovery even though she had consumed a staggering quantity of mushrooms.

In probably the weirdest case (and one that may well be a fabrication), one of the NAMA toxicology identifiers spotted a long rambling post on the website by a heavy user of numerous different hallucinogens. While under the influence of “MSE” (probably actually MXE, methoxetamine, a PCP analog), he claims to have gone out at night and collected, then consumed, about 50 mushrooms. In his drug-influenced state, he identified them as “Big Laughing Gyms.” The next day he started feeling more and more ill, returned to his collecting site, and then identified the mushrooms as Galerina marginata, a deadly amatoxin-containing species. He reported to the emergency room but they supposedly did not believe there was any mushroom poisoning involved and wanted to do numerous expensive tests, so he reports that he left and treated himself. He claims to have ingested activated charcoal and consumed milk thistle capsules to cure himself – but he started treatment too late for charcoal to be of use and milk thistle capsules, which are widely believed to protect the liver, are ineffective since they are not absorbed into the blood stream and so are of no help either.

There were reports dealing with 75 people (70 incidents) suffering non-life-threatening conditions after consuming mushrooms. Thanks to the work of Marilyn Shaw, the numbers reflect detailed reporting for the region covered by the Rocky Mountain Poison and Drug Center (Colorado, Hawaii, Idaho, Montana, and Nevada). We also have detailed reporting from Michigan thanks to the cooperation of Susan Smolinske at the Children’s Hospital of Michigan Poison Center. Her volunteer intern, Hanady Nasser-Beydoun, prepared a spreadsheet for us of all symptomatic mushroom poisoning cases that their center had handled. For the rest of the country, we know that reporting is very incomplete, so our numbers really cannot be used to indicate whether poisoning incidents are increasing or decreasing with time or whether poisoning incidents are more common in one region than another. Because of reports to the Rocky Mountain Poison and Drug Center and the Children’s Hospital of Michigan Poison Center, we received a significant number of reports of adverse reactions to hallucinogens. At least 14 reports involved adverse reaction to species in the genus Psilocybe. In two cases of Psilocybe ingestion, the patient became combative.

Chlorophyllum molybdites accounted for 12, possibly 13, of the reports of adverse reactions to mushrooms. Often the victim had only consumed one bite raw. Cooking seems to decrease the severity of the symptoms, but even cooked C. molybdites can cause significant gastric upset. One husband (an MD) treated his wife at home using Gatorade® after finding the hospital to be of little or no help. Two other individuals self-medicated with Gatorade® to replace electrolytes lost from excessive vomiting and diarrhea after consuming C. molybdites.

Adverse reactions to morels accounted for 10 of the reports. One case involved raw morels; the other cases involved cooked morels. One case involved alcohol with the meal. Whether that individual can eat morels without alcohol was not established. For some people, it is unwise to consume alcohol with a meal of morels, though a significant majority of individuals can enjoy a beer or wine with a morel meal. It is becoming increasingly clear that some people can develop sensitivity to morels and suffer gastric distress after a morel meal when they had previously eaten morels for years without incident. We have even received the first report of life threatening anaphylactic shock from morels. The affected individual had previously eaten morels for years without adverse effect.

Five individuals in three separate incidents were sickened by puffballs, both Calvatia species and Lycoperdon species. Puffballs are normally only a problem if they are no longer pure white inside. However, in these cases, victims said that they had consumed mushrooms that had not yet started to mature and darken inside.

Five cases involved purchased mushrooms. Four cases involved individual sensitivity to a specific species (one sensitivity to Pleurotus ostreatus, two to Lentinula edodes (shiitake), and one sensitivity to Agaricus bisporus (crimini)). The fifth case was troubling since it involved sale of the poisonous species, Omphalotus illudens, by an unreliable wild crafter. The chef at the restaurant where the mushrooms had been purchased sampled the dish before placing it on the menu, so only he became ill.

The final human case of particular note involved a case of kidney failure after mushroom ingestion of an unknown species. Kidney failure is exceptionally rare, having been reported only for Amanita smithiana (and possibly some other Amanita species in section Lepidella) and for a few UV-fluorescent Cortinarius species (only one case in North America and that was due to ingestion of Cortinarius orellanosus). It is unfortunate that the mushrooms were not identified in this unusual case.

We received 26 reports of dogs and one horse poisoned by mushrooms, 11 of the dogs died. Eight of the dog cases involved suspected amatoxins with six deaths, five from confirmed or suspected Amanita species in the section Phalloides, one from suspected Galerina marginata. It is notable how rapidly dogs can succumb (as quickly as 55 to 60 hours post ingestion). When amatoxins are suspected, it is imperative that aggressive rehydration be begun rapidly, especially since dogs typically refuse to eat or drink after consuming mushrooms that contain amatoxins.

One dog death was attributed to consumption of Amanita muscaria. The dog was given two doses of atropine as part of the treatment. However, atropine is strongly contraindicated with poisonings involving mushrooms in the Amanita muscaria group, the Amanita pantherina group and Amanita aprica where muscimol and ibotenic acid, not muscarine is the toxin (Beug and Shaw, 2009). Two dog deaths were attributed to ingestion of Inocybe species and one dog death to suspicious unknown causes.

The problem of untrained individuals using the internet (or for that manner a book or other source) to identify mushrooms on their own came to light when a woman wrote that her dog was poisoned by what she had confirmed was Amanita pantherina and that the symptoms matched poisoning by ibotenic acid and muscimol. However, the reported symptoms actually matched lycoperdonosis. This was confirmed when a picture of the mushroom was sent in. It was an old Lycoperdon. The correspondent confirmed that when the dog bit into the mushroom, a cloud of dark green spores arose. The symptoms had been caused by inhalation of that cloud of spores.

To read the full article with tables, follow this link…
Scroll to Top
Skip to content