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2013 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 2013, NAMA received mushroom poisoning reports involving 67 people, 49 dogs and 1 cat. No human deaths were reported to NAMA in 2013. There were seven cases involving ingestion of Amanita species containing potentially deadly amatoxins. In one incident, the person had consumed seven Amanita bisporigera mushrooms and survived without needing a liver transplant. He received aggressive treatment following the protocol developed by Dr. Todd Mitchell. Dogs did not fare nearly as well when they ingested mushrooms containing amatoxins. Three to five deaths were from consumption of mushrooms in Amanita section phalloideae, one dog death was from amatoxins in Galerina cf. marginata and one dog death from amatoxins in Lepiota cf. subincarnata (= josserandii). Of five dogs who consumed Inocybe species (muscarine containing), one died. One dog died from eating a whole pile of Morels. Five dog deaths were from unknown causes where mushrooms were suspected. One cat death was reported after the cat consumed Amanita muscaria.

The 2013 mushroom season was notable for the absence of human fatalities reported to NAMA. The number of cases of ingestion of Amanita phalloides in the Pacific Northwest rose from a normal of 0-1 cases to five cases due to late summer and early fall rains that led to an outstanding mushroom season with large flushes of Amanita phalloides in the parks of Portland OR, Seattle WA, and Vancouver B.C. In contrast, severe drought in California meant a greatly reduced mushroom season and no reported human ingestions of any Amanita sect. phalloideae mushrooms. In the rest of the United States and Canada, human ingestions of mushrooms in Amanita sect. phalloideae were low compared to other recent years. We did, however, read of one extended family from southern Mexico where four boys 10-17 years old and one girl of 14 died, the parents survived after a long hospital stay, and the grandfather who consumed only a little of the meal, survived without hospitalization. In contrast, in New York, a 65 year-old man survived a meal of seven deadly Amanita mushrooms (consumed raw) after aggressive treatment following the still experimental protocol of Dr. Todd Mitchell of Santa Cruz, CA. In one other New York case, a 75 year-old man consumed just one Amanita. Success in his case was attributed to use of activated charcoal, N-acetyl cysteine, and oral milk thistle, but I would attribute the success solely to the IV fluid replacement and the consumption of only a small amount of mushroom. There is no convincing evidence that activated charcoal, N-acetyl cysteine or oral milk thistle are of use in treating amatoxin cases, though this protocol remains the currently accepted procedure in North America. My current best advice is to have the doctor or hospital immediately contact Dr. Todd Mitchell in the event of a suspected amatoxin case. By the close of the 2013 season, we had received reports of seven people from the United States and Canada sickened by amatoxin-containing mushrooms plus sixty other cases. Six people were hospitalized after ingestion of Amanita muscaria, six were ill after consuming red Russula species, and three were ill after mistaking Scleroderma species for puffballs. Seven very bad trips on Psilocybe species were reported and four people reported a flagellate rash after consuming either raw or undercooked Shiitake (Lentinula edodes). There were four incidents of people ill after consuming assorted packaged mushrooms. At least some of these mushroom assortments had their origin in Yunnan Province, China. While hunting with David Arora in October, he told me of visiting mushroom markets in Kunming, China where he observed toxic mushrooms on display as well as edible species. He learned that dealers buy everything and sell the toxic species mixed in with the edible ones, apparently relying on no one getting enough of any one toxin to wind up severely ill. One ill U.S. purchaser of dried Porcini (from a Minnesota mail-order source), found pieces of unidentified gilled mushroom in with her Porcini. Not all middle-of-the-night calls to NAMA identifiers involved a poisoning. One toxicology identifier, Sister Marie Kopin, got a 3:30 AM call from a lady concerned about mushrooms growing on a door in her house. It turns out that there was a leaky bathroom above.

One intrepid mushroom collector, determined to eat everything  he brought home, no matter how long it had lingered in the refrigerator, repeatedly learned that eating heavily maggot-riddled decaying mushrooms can lead to several hours on and leaning over the porcelain throne.

In hunting mushrooms with David Arora, our conversation also turned to tasting unknown mushrooms as part of the identification process. I use all of my senses when identifying mushrooms. I rip mushrooms apart to understand texture, I smell them, and I chew them (and then spit out the remains). I tell students that they can safely taste any unknown mushroom, even a deadly Amanita, as long as they spit it out, but that tasting a plant could kill you. Other than an occasional burning sensation from a peppery Lactarius or Russula, or a bitter taste or a foul taste from time to time, I have only once had a bad reaction. That was to Crepidotus cf applanatus and I felt like my throat had swollen shut and I could not breathe for a moment. David then told me of his friend Ryane Snow who was demonstrating to a class that you could safely taste any mushroom, even Boletus pulcherrimus. He chewed a small piece in front of the class and was quickly nauseous and then dizzy for hours. He repeated the demonstration to a different group a few weeks later and this time he was dizzy and nauseous as soon as he merely touched his tongue to a piece of Boletus pulcherrimus.  In response to reading the Boletus pulcherrimus story, Bill Bakaitis reported a similar case where a woman prepared a breaded and fried large puffball. She reported that as soon as the fork touched her mouth, she experienced swelling of the lips, tongue, and throat even though she did not chew or swallow any of the mushroom (no one else in the family had any reaction). Bill felt that her case may be the result of the power of Classical Conditioning on the Autonomic Nervous System – for example laboratory animals can be ‘trained’ to die from innocuous stimuli that have previously been paired with toxic substances and later presented without the toxic agents.

I learned more about the challenges of figuring out poisoning cases in one human poisoning that involved a report from a family member (“with some medical training”) about a hospitalized individual suffering Rhabdomyolysis-induced kidney failure, something never before seen in a North American case. I received photos of a mixed table full of mushroom species, mostly a red-capped Russula, but various other white-gilled species. Knowing that red-capped Russula species can cause nasty symptoms, I concluded that was the probable problem. Slowly, over many email exchanges, I learned of delayed onset symptoms with elevated liver enzymes. I looked again at the pictures where I now noticed what looked like it might be the cap and upper half of the stem of a “destroying angel” Amanita cf bisporigera. I jumped on the amatoxin bandwagon, but the reported Rhabdomyolysis puzzled me. Was the Rhabdomyolysis due to a mixed ingestion with the Russula species? Was this a newly reported effect of amatoxins? The yard was re-examined and “destroying angel” mushrooms were growing there. Eventually, Dr. James Addison went into detective mode and solved the case. He has written up a report for (along with lots of helpful definitions of medical terms). Suffice it to say for this report — I was just looking at the mushrooms left that were NOT eaten. The amatoxin conclusion was off base.

For animals, we report just the 49 cases where the culprit mushroom could be determined reasonably well or where the case itself was very unusual. There were twelve reported dog deaths and one cat death. The cat consumed Amanita muscaria in the owner’s home. Cats are not known to eat mushrooms that are growing outside, but they will eat Amanita muscaria found indoors, especially when dried. For cats, Amanita muscaria consumption is often fatal. For dogs, Amanita muscaria (and Amanita aprica and Amanita pantherina) is typically only fatal if the dog is very young (one death this year), very old (one death this year), consumes a large quantity (both the puppy and the old dog this year), and or is treated with atropine or valium at the vets. This past year, one dog was treated with valium, a central nervous system depressant, which greatly slowed its recovery. Since ibotenic acid and muscimol, the main toxins of Amanita aprica, Amanita muscaria and Amanita pantherina, are also CNS depressants, the dog stayed in a comatose state much longer than would have normally been expected. One other dog poisoning from Amanita muscaria var. alba was massively over-treated by the vet, probably resulting in a longer recovery than would have happened had the dog’s stomach simply been pumped (if needed) and IV fluids administered.

Amatoxins could be confirmed or strongly implicated in the death of five dogs. Three cases involved Amanita species in section phalloideae , but one dog died from amatoxins in what appeared to be Galerina marginata and one died from toxins in what appeared to be Lepiota subincarnata. Most years many dogs in California consume deadly Amanita species, but with the drought, dog deaths in California were significantly reduced.

There were five reported cases and one death where dogs consumed Inocybe species. Dogs frequently consume and are poisoned by Inocybe species. In one instance, a couple had gathered a large haul of morels and turned their attention away. They returned to find that the dog had gulped them down. The dog died. Five other dogs died from unknown toxins where the owners were convinced that the cause was mushroom poisoning, but partially consumed mushrooms were not found in the yard. Chunks of mushroom were not observed in the dog vomit either. Consequently, these cases remain a total mystery.

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