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Home , Amanita smithiana, Boletus edulis, Chanterelle, Edible mushroom, Grifola frondosa

punctipes, courtesy T. Lockwood.

16 FUNGI Volume 14:2 Spring 2021 North American Poisonings and Adverse Reactions to 2018–2020

Michael W. Beug Toxicology Chair, North American Mycological Association

n his article “World Mushroom reported involve consumption of raw contain heat-labile carcinogens. However, Production: An Overview” (FUNGI or only lightly cooked mushrooms. some toxins, like amanitins, are not 14[1]: 8–13) Dr. Britt Bunyard The culprit is , a chemical that decomposed on heating and so species Ireported that there has been a 30-fold receives broad use in cancer in containing amanitins (notably increase in commercial mushroom and some other Asian nations. species in the Section Phalloideae, like production since 1978. World per capita However, about 4% of all people have and the Amanita mushroom consumption has grown to an adverse reaction to lentinan, which bisporigera group remain toxic even after 4.7 kg/year from 1 kg/year in 1997. Over in susceptible individuals, can cause ). half of all mushrooms consumed are rupture of the microcapillary blood Mushrooms may also be contaminated cultivated edibles, 38% are medicinals, vessels. The result is a very painful rash by bacteria which would be killed on and 8% are wild harvested. that can last for a week or more. The cooking. I was curious about how these changes rash is known as “ flagellate species (oyster and king might be reflected in mushroom- dermatitis.” Lentinan is destroyed by oyster mushrooms) are the second most poisoning data. I had not summarized heating, so cooking the mushrooms widely cultivated edible mushrooms, the poisonings reported to NAMA prevents the painful rash. A very tiny occupying 19% of the cultivated sales since 2017 and it was time for me to percentage of people have an adverse market. While most people tolerate update the case reaction even to well-cooked shiitake, cooked oyster mushrooms, consumption registry. The full update, “Summary of typically suffering , vomiting, of raw and undercooked oyster the Poisoning Reports in the NAMA intestinal cramps, and nausea. There mushrooms is a very significant cause Mushroom Poisoning Case Registry: are no mushrooms, indeed no foods of of gastrointestinal upset, sometimes 2018 through 2020” was published in any kind, that do not cause problems for leading to hallucinations. On rare McIlvainea vol. 30 (2021) and is available some sensitive individuals. Shiitake is occasions, someone will have a bad free online at www.namyco.org. In this possibly the most widely tolerated of all reaction even to well-cooked oyster note, I highlight findings from the full foods—if it is well cooked. mushrooms if they drink alcohol with report. Tables I and II are reproduced Thorough cooking is important for all their meal. However, most people from McIlvainea vol. 30. edible fungi. The exception is . can eat oyster mushrooms and drink It is noteworthy that the NAMA data The cell walls of fungi are , which alcohol with no problem. One woman is a result of voluntary reporting and is very indigestible, but is made more who consumed several raw stipes of only captures a small fraction of the digestible on cooking. Though I have not cultivated blue oyster mushrooms adverse events in any one year. Most seen it reported recently, consumption suffered chills, flushing, diarrhea, adverse reactions (to any mushroom) go of raw and undercooked mushrooms intestinal cramps, sweating, muscle unreported to NAMA. can lead to a bezoar, a serious blockage spasms, vomiting, drowsiness, weakness, Globally, Lentinula edodes (shiitake) of the stomach or intestines due to headache, and blotchy skin on her face. is the dominant cultivated mushroom the formation of a bolus of undigested I no longer eat any oyster mushrooms at 22% of world cultivated mushroom material. Several edible mushrooms, because 1) there are many other species production. Prior to 10 years ago, I had most notably morels (indeed, all that I like far better and 2) I have seen never seen a reported adverse reaction species of edible ascomycetes, except too high a percentage of bad experiences to shiitake in . Now culinary truffles), are poisonous raw, with Pleurotus species. adverse reactions to shiitake are one of containing unknown compounds that Auricularia species (wood ears, also the 10 most common events reported are decomposed upon heating. Other called black ), a flavorless jelly to NAMA. Most of the adverse cases species, including species, mushroom with great texture, are third Spring 2021 FUNGI Volume 14:2 17 Flammulina velutipes, courtesy N. Craig.

in annual production. I had expected poisonings reported to NAMA over or winter mushroom), at 11%, ranks them to also be prominent in the toxicity the past three years (8 cases). This is fifth in global production. I have no category, but have not had a single counting both “edible” and “poisonous” recent reports of adverse reactions report of a bad reaction for several years species! The problem is typically from the mushroom itself, which is now. They are very popular in Chinese gastrointestinal upset accompanied by prized both for its healthy properties cuisine and are used medicinally for flu-like symptoms. In some cases, there is (low cholesterol, etc.) and for a range purported antitumor, hypoglycemic, a clear allergic reaction accompanied by of purported medicinal benefits. anticoagulant, and cholesterol-lowering rash. A good way to tempt fate is to help However, contamination by Listeria properties. The anticoagulant properties yourself to some of the raw sliced button monocytogenes, found growing on are very real and lead to a poisoning mushrooms typically found in imported enoki mushrooms, led to 31 known as Chinese restaurant syndrome. bars. Pass on them and do the restaurant people hospitalized plus four deaths The blood-thinning properties can owner a favor and tell them not to serve in 17 states in June of 2020. When lead to excess bruising and horrendous raw or only lightly cooked mushrooms. purchasing cultivated mushrooms, I only menstrual periods. Unwary diners on From the wild, I place Agaricus species buy American. While problems with blood thinners are in danger of too much in one of two camps. The prized almond imported mushrooms are not common, blood thinning and excess bleeding. or -smelling species (all edible for I see such reports often enough to be Agaricus species, mainly Agaricus most people) and the ones that smell wary of imported mushrooms, even bisporus (the common button a bit like wet asphalt (poisonous for dried mushrooms. Cultivation practices mushroom, also known as baby bellas, most people). I have never tried one in North America mean that mushrooms crimini, and portobellos) occupy of the foul-smelling species, but even from North America are far less likely to fourth place in global production. Until the choice almond-smelling species be contaminated. this most recent three-year period, like Agaricus augustus will give me I have also seen a recent surge in rarely showed up in gastrointestinal distress. One consumer reports of people becoming ill from mushroom poisoning reports. However, of a foul-smelling Agaricus species, when bags of imported dried mushrooms with the huge increase in mushroom presenting at the hospital for treatment, containing a mixture of species. If you consumption, Agaricus bisporus noted that they tasted “a bit off.” suffer gastrointestinal distress, how has climbed to number one in total Flammulina species (enoki, , are you to know which species in the 18 FUNGI Volume 14:2 Spring 2021 mixture caused your problem? When different properties than the fruitbody purchasing dried mushrooms, stick to and both can be beneficial. single species. You can mix your own Among the medicinal mushrooms, later once you have safely eaten each I see the most problems with Inonotus species separately. obliquus (chaga). Chaga forms a black Cultivation of medicinal mushrooms canker typically on birch trees in accounts for about 38% of global northern latitudes. I have case reports production. I regularly consume a few of people harvesting a black growth on species of “medicinal mushrooms.” and a different black growth My number one favorite is on cherry trees that were not chaga, erinaceus (lion’s mane). Cultivated and both caused severe gastrointestinal species have a great texture and a distress. Just because something is a very nice flavor. Wild lion’s mane in does not necessarily mean my area like lobster. I prefer it that it is not poisonous. Even when to every other edible species. In Asia correctly identified, things do not one important use is in slowing the always go well. In one case involving progression of dementia. In vitro study unspecified preparation, an individual evidence indicates that it has powerful suffered hepatitis and renal failure from neurogenerative properties. Maybe it “chaga.” In a second case, consumption will slow my own growing dementia; of “chaga” tea led to three days of it certainly cannot hurt. It certainly is vomiting and confusion, elevated liver delicious. Another powerful, but little , elevated serum creatinine, and appreciated, medicinal mushroom is coagulopathy. In a third case a person edulis. The stipes are loaded with drank “chaga” tea for two weeks and beta glucans, which many people believe then his trunk and legs turned purple. are very good for you. I eat as many king Another kept a container of “chaga” tea, as I can find. Just don’t mess drinking from it regularly, winding up up and consume an East Coast look- hospitalized after the tea turned moldy. alike, Boletus huronensis. It can cause Among other , I have four nasty and long-lasting gastrointestinal recent reports of gastrointestinal distress distress. I consume two lion’s mane from frondosa (maitake or hen capsules and one Trametes versicolor of the woods). For most people, this (turkey tail) capsule every weekday. I is a prized edible. I certainly would strongly believe in the ability of turkey not hesitate to consume it. But as tail mushroom capsules to aid in dealing with all foods, for some it can cause with solid cancers. However, harvesting gastrointestinal distress or worse. One in the wild can present problems. First, case is particularly instructive. An there are a lot of turkey tail look-alikes adult woman reported her experience when viewed just from the top. It is the consuming this mushroom on four combination of the appearance from the different occasions. The mushroom was top plus the small white pores on the thoroughly cooked each time. After the underside that is distinctive. Also, some first two meals, all was well. However, cultivars have much higher production the third meal produced a minor of beneficial compounds than others and stomachache. The fourth meal resulted so with wild harvesting you never know in intestinal cramps and vomiting. Her whether you are picking a potentially body has probably developed a sensitivity medicinally useful mushroom or to this species and were she to continue one with only low production of the eating maitake, each subsequent episode chemicals of interest. Finally, make sure could be much worse. that if you do harvest from the wild The polypore complex that you harvest fresh, prime material. sulphureus, L. cincinnatus, L. Old turkey tail mushrooms can cause conifericola, and L. gilbertsonii is significant gastrointestinal distress. Even particularly problematic with four with purchased “turkey tail” capsules, it recent cases in the NAMA case is important to buy from someone who registry. A woman from Georgia has researched many cultivars to find reported consuming a large amount one with strong medicinal properties of boiled and then thoroughly sautéed (based on test tube or Petri dish studies). mushrooms. She had an allergic reaction It is also important to realize that the and broke out in hives that lasted mushroom can have very a couple of weeks. A woman from Spring 2021 FUNGI Volume 14:2 19 New York consumed ¾ cup of well- eating these boletes for years and then “edible” to the “poisonous” category. cooked mushrooms. She had eaten this suddenly developing a sensitivity to Even well-cooked specimens can cause species once before and suffered slight them, developing flu-like symptoms that sufficiently severe diarrhea, intestinal indigestion. This time it was a full-blown can last for a week or more. For some cramps, vomiting, nausea, and weakness allergic reaction resulting in chills, people, even the first meal is problematic. to send one to the hospital. We had four salivation, dizziness, intestinal cramps, There are seven recent reports of adverse such reports in the database. muscle spasms, vomiting, weakness and reactions to species, putting Morchella species often take first place rash. A few years ago, an Oregon woman this group second only to Agaricus for for causing the most adverse incidents took two bites of L. conifericola and died number of reports. If you do continue over the course of a year, even beating from anaphylactic shock. I steer clear of eating these, make doubly sure that they out the always-toxic Chlorophyllum all Laetiporus species. are very thoroughly cooked (and even molybdites. There is no way I am going Leccinum species were once regularly that may not be adequate). to stop eating morels. They are just too on the menu at our home. No longer. I Sutorius () eximius is another delicious. However, I do not trust other have seen too many reports of people that needs to be moved from the people to cook them thoroughly and so Table I. Summary of Human Cases.

Toxin or Number of Notable Observations Poisoning Syndrome Cases

No deaths. One person survived eating ½ and Amatoxins 10 cases survived without treatment.

Two young children escaped with no symptoms due to fast treatment. Isoxazoles 13 cases One adult consumed huge quantity and was treated with atropine and experienced respiratory failure—recovered after 8 days.

One probable anaphylactic shock. Two atypically severe cases involving purchased Psilocybe species that were likely adulterated. One young child Psilocybin 7 cases promptly treated had no symptoms from P. cyanescens which can cause death in young children.

Second ever orellanine case reported in North America. Orellanine 1 case Severe kidney damage.

Allenic norleucine 1 case + Violent poisoning. No mention of typical kidney damage. Always from chlorocrotylglycine 1 possible Amanita smithiana.

Bleeding None

Cases of possible alcohol reactions due to individual sensitivity recorded Alcohol syndrome None under gastrointestinal cases.

Gyromitrin None

One DEATH from a (from 2014). One gastrointestinal case where one Clitocybe may have been consumed. One severe 3 cases + Muscarine gastrointestinal case where an Inocybe was consumed to get high. One 1 possible young child case involving part of an Inocybe, prompt treatment, and no symptoms.

Contamination by 1 Four DEATHS, 31 hospitalized in 17 states. Listeria shipment

Many lessons here but the most important is that some people can Gastrointestinal become sensitive to a mushroom that they have eaten for years. Repeated 130 cases and/or shock ingestions of that species can lead to increasing severity of symptoms. Historically has caused deaths from anaphylactic shock.

20 FUNGI Volume 14:2 Spring 2021 only eat ones that are clearly fresh (not practice. Cooks have died from inhaling and ) was implicated starting to rot) and that I have cooked the vapors while cooking. in 13 human cases (two Amanita myself. In this most recent period, There were five reports of adverse multisquamosa, five , morels tied with C. molybdites at six reactions to Hypomyces lactifluorum and six Amanita pantherinoides incidents. Morels are clearly poisonous (lobster mushroom), though two of (=American A. pantherina) plus many raw, but none of the six reports involved those involved mixed collections. This dog cases and one case involving three raw mushrooms, though a couple of species has only recently started showing ducks (a first ever report involving any cases were suspect because of light up in the NAMA case reports. In two species of bird). On the day the ducks cooking. Symptoms generally include cases, the individual reported that they consumed A. pantherina, the ducks were dizziness, disorientation, intestinal had previously eaten lobster mushrooms so sick that the owner thought that they cramps, vomiting, drowsiness, sweating, for years without adverse effects. would all die. However, the next day they and flushing. A few people cannot eat Reported effects include chills, intestinal had all fully recovered. The symptoms morels and drink alcohol, though most cramps, sweating, vomiting, nausea, in the ducks were just what one would people can do so without . weakness, and headache. expect from either a human or a dog Some people who have eaten morels Among toxic mushrooms, species case. The recovery was also typical. without incident for years, can suddenly containing amatoxins are the most Of the human isoxazole poisonings, develop a sensitivity to them. If that feared. Ten human case reports involved some of these involved intentional happens and you eat morels again and suspected or confirmed amatoxin ingestions by individuals intent on the reaction is even worse, stop eating poisoning. There were no reported getting high and who wound up in morels. Another meal could prove life human deaths or liver transplants in the hospital for their efforts. These threatening. This warning is true for the past three years. Many more cases species all contain muscarine as a any that you become involved dogs (where the outcome is secondary toxin. Muscarine poisoning is sensitive to. usually death). The human amatoxin counteracted with precise doses of the Morels do not contain significant cases included two with Amanita toxin atropine. However, in dogs who quantities of , if any at all. bisporigera (including one person who have ingested isoxazoles, use of atropine Gyromitrin is found in significant survived without seeking any treatment), is contra-indicated since it exacerbates quantity in , G. three or possibly four with Amanita the isoxazole poisoning and can lead to ambigua, and G. infula as well as in phalloides (including one unsuccessful death. Atropine was also used in one Cudonia circinans. Fortunately, we suicide attempt), and one each with human isoxazole case and appears to have had no poisoning reports from Conocybe filaris, Lepiota lilacea, have significantly increased the severity any of these four toxic species over the and Lepiota subincarnata and one of the poisoning. past three years. Gyromitrin is highly apparent amatoxin poisoning due to an Several human and dog cases involved carcinogenic and can cause severe liver unidentified species. There were no cases ingestion of Inocybe and Clitocybe damage, even death. Thorough cooking due to Galerina autumnalis/marginata. species that are high in muscarine. These (outside) will destroy the gyromitrin This was a first ever report for both L. species contributed to several dog deaths and vaporize the toxic monomethyl lilacea and C. filaris. and the first ever human death (in the hydrazine, rendering G. esculenta Inebriation and poisoning by isoxazole NAMA database) from a Clitocybe. edible, though I do not recommend the compounds (notably Reading through the full report in Table II. Overall Summary of Animal Cases.

Toxin or Number of Notable Observations Poisoning Syndrome Cases

Amatoxins 15 cases Twenty DEATHS, 2 recovery (1 from Amanita phalloides, 1 from 25 dogs Lepiota subincarnata). The rest, largely unknown outcome. Isoxazoles 11 cases Three DEATHS (all dogs). First mushroom poisoning report of any 11 dogs + kind involving ducks. Duck symptoms typical for isoxazole poisoning, 3 ducks 24 hour recovery. Muscarine 12 cases Two DEATHS. 15 dogs Psilocybin none Dogs are known to seek out and consume Psilocybe mushrooms. Gyromitrin 2 cases One DEATH.

Gastrointestinal 18 cases Three DEATHS. Two DEATHS from unknown toxins in Amanita 19 dogs (Saproamanita) thiersii. One DEATH from probable Panaeolus foenisecii.

Spring 2021 FUNGI Volume 14:2 21 McIlvainea, you will note several additional species with just one or two reports of adverse effects. One remaining case of note was a very serious poisoning by , one of two North American Cortinarius species known to contain orellanine, a chemical with a very long lag time between ingestion and symptoms (days to weeks). Orellanine leads to loss of kidney function and can result in death (several cases in ) or the need for a kidney transplant. There has only been one other recorded orellanine poisoning case in North America and that was a Michigan case due to C. orellanosus. While C. rubellus is a associate found in sphagnum bogs, C. orellanosus is associated with hardwoods. Both are mistaken for , though the gills of the Cortinarius species are distinctly different from the blunt ridges of a . Consumption of Psilocybe species in the right set and setting, and under proper guidance, can have exceptional medical benefits. At numerous psychedelic mushroom conferences where Psilocybe mushrooms were consumed, I have never observed a “bad trip” (and yes, on all but one occasion, I was simply an observer). However, misuse can have significant adverse consequences. One “bemushroomed” individual consumed an assortment of small brown Entoloma species and was severely poisoned. In a second incident, someone experienced temporary paralysis. Though rarely reported to NAMA, poison centers regularly deal with “bad trips.” In two British Columbia cases and one other Canadian case, two involving purchased Psilocybe cubensis and one involving purchased Psilocybe cyanescens, the symptoms lead me to suspect that the purchased mushrooms had been adulterated with additional, more dangerous, psychoactive substances. Chlorophyllum molybdites normally leads the pack for all mushroom poisonings. I had four reports of people who consumed this mushroom raw. It caused very violent poisoning including bloody vomit and bloody diarrhea. Cooking does not render C. molybdites edible. Until creating this report, I had never heard of a human death due to muscarine. However, an old report from 2014 was turned in reporting a human death from a Clitocybe species. In one other case, while seeking mushrooms to get him high, an adult suffered muscarine poisoning after consuming Inocybe sindonia collected on a roadside (collecting in such a contaminated environment is a problem on its own). The hospital bill probably proved quite steep, but he did survive.

22 FUNGI Volume 14:2 Spring 2021