by Greg Marley
As with an increasing number of people and foods, a few mycophagists develop allergic reactions to certain mushrooms, ranging from mild rashes to gastrointestinal disturbance or worse. A few people also develop an allergic sensitivity to mushroom spores. The risk posed by high concentrations of mushroom spores became known only following the increased cultivation of shiitake and oyster mushrooms in controlled indoor fruiting rooms during the 1980s. People employed to harvest the mushrooms are exposed repeatedly to high concentrations of spores when harvesting the mature fruiting bodies. Health officials began to note a rise in cases of this hypersensitivity pneumonitis in Japan and China where up to 10 percent of oyster mushroom workers develop symptoms.5 This has also been reported among workers in the U.S. oyster mushroom cultivation houses.
My Inevitable Personal Story of Mushroom Poisoning
Sometimes a pattern of “idiosyncratic reactions” gives us enough cause for concern to re-label an edible mushroom as suspect or toxic. One example of this hit close to home with me, very close.
In August 1986, an abundance of rainy, foggy, overcast days made the tourists on the coast of Maine depressed and the mushroomers ecstatic. During those days, I embarked on regular mushroom hunting excursions and, one day, came upon several fine specimens of a bolete that was new to me. They were distinctive, large mushrooms with a purple-brown cap and a deep chocolate pore surface in place of gills. The inner flesh was pale lavender-brown throughout and firm. The mushrooms were fruiting singly in a mixed hardwood forest. I brought some prime specimens home in my basket and set out determining their identity. A spore print generously deposited showed pinkish-buff brown spores and confirmed that I was looking at a species in the genus Tylopilus. A review of several mushroom field guides including Gary Lincoff’s Audubon Field Guide to North American Mushrooms and David Arora’s Mushrooms Demystified left me little doubt that I had a basket of Tylopilus eximius, the lilac brown bolete. Both books reported the species as edible and Audubon indicated that the few look-alike species were not toxic. So being young (thirty-one) and adventurous, not to mention hungry, I cooked up the mushrooms by sautéing them in olive oil with garlic and salt and pepper, finishing them with a bit of cream and eating them over fettuccini with Romano cheese. Quite yummy!
Two hours later, while I was at work, I began to feel the rumbles and flip-flops of impending trouble. I immediately guessed it was the mushrooms not agreeing with me, and assumed that I would get sick, get rid of the offending contents, and then get over it. Several torturous and embarrassing hours later, I ended up in a local emergency room when my co-workers became so alarmed they called an ambulance. There I spent an extremely uncomfortable night on Compazine and IV fluids before being released in the morning.
I was interested in how I could have made such a painful mistake in identification or judgment, so I continued to seek collections of and information about this very distinctive mushroom. Both Louis Krieger6 and Charles McIlvaine7 agreed with the edibility call and noted that the specific epithet “eximius” means select. But in talking with other mushroomers, most notably Sam Ristich, the mycological guru of New England, I learned that several other people had ended up in emergency rooms around Maine after eating the same mushroom in 1986. I reported my case to the National Mushroom Poisoning Case Registry managed by NAMA as, I hope, did others involved with similar cases. When Roger Phillips published his popular guide Mushrooms of North America in 1991, he became the first field guide author to add a note of caution to the edibility of T. eximius. Over the intervening years the mushroom poisoning community in New England has become aware of perhaps a dozen or more cases of severe GI distress caused by eating T. eximius. I have heard of no cogent explanation for the toxicity of T. eximius in the Northeast when it has been eaten in other regions of the country for an extended period of time. The populations in the Northeast may have developed additional chemical toxins or we may have a slightly different variety of Tylopilus. In any case, I have not tried it a second time, thereby demonstrating my ability to learn from experience. Vomiting is not on my list of most desired activities.
A number of people assumed that, following my episode of mushroom poisoning, I would stop collecting and eating wild mushrooms. They expressed their surprise in varying fashion, but certainly some deepened their doubts about my judgment (or lack thereof) when I told them about my intention to continue eating wild mushrooms. My response to them was to ask if they have ever suffered food poisoning after eating out. The overwhelming majority replied, yes. I then asked if they continue to eat out. Generally they answered with some indignation, “Well certainly not at the place where I got sick!” Alas, I, also, no longer eat the lilac-brown bolete.
To put my personal saga of mushroom misadventure into context, I have collected and eaten wild mushrooms since the mid-1970s and over the years have tried more than fifty different species. During this period, I have been sickened only this once. Over the same period of time, I have easily enjoyed a thousand great meals of wild mushrooms and shared many of them with family and friends. Nobody has ever complained of more than an overfull feeling.
The risk of being sickened by eating wild mushrooms is real, but the potential for many fine meals of incomparably fabulous fungi is at least as real and much more likely to occur if you follow basic precautions outlined in this book. The task for the mushroom forager is to bring caution, preparation, and excitement into play in roughly equal proportions and to do your homework in order to learn about the potentially toxic mushrooms as you consider edible mushrooms for the table. Start slow, start small, and have fun.
Toxic mushrooms are generally grouped by the type of toxin they contain, and more specifically, the effects of the toxin on the human body. Officially, there are eight groups of toxins, though the incidence of poisoning in several of the groups is quite rare in the United States. The most dangerous and life threatening of the toxins have spurred scientists to understand their structure and mode of action. Thus we know a great deal about the amatoxins (see Chapter 8). We also have learned about the structure and action of gyromitrin from false morels (see Chapter 9). On the other hand, we know relatively little about the structure and specific mode of action for a range of compounds responsible for the most common presenting symptoms of mushroom poisoning, the gastrointestinal irritants.
The most frequently encountered set of symptoms in mushroom poisoning mimic those I experienced after dining on the lilac-brown bolete, Tylopilus eximius. They generally include mild to severe gastrointestinal distress including nausea, vomiting, diarrhea, and perhaps abdominal cramping generally lasting less than twenty-four hours and often accompanied by a general feeling of malaise. If the victim has poor health, the poisoning can further compromise their functioning and the very rare deaths have occurred under these conditions. In a healthy adult, the effects usually pass without lasting damage to any bodily system save to one’s self-confidence regarding mushroom identification.
In general, the more quickly symptoms of mushroom poisoning develop, the less severe the outcome. Muscarine toxicity and the effects of hallucinogenic psilocybin and psilocin generally are seen within thirty minutes and pass within five hours. Most often they leave benignly, though there are occasional severe reactions to muscarine and it has caused a few deaths worldwide. Muscarine is the only mushroom toxin for which there exists an antidote. Victims recover rapidly when given an IV with atropine.8 Muscarine is a toxin that causes profuse salivation, tearing of the eyes, sweating, and increased urination, among other symptoms.
The toxins responsible for more severe and lasting damage generally have a delayed onset of initial symptoms ranging from six hours to several days. I will not review all of the known classes of mushroom toxins in depth here. It seems more valuable to focus on the general paths to making unfortunate mistakes as a method to underscore how to avoid them. For an excellent and thorough treatment of mushroom poisoning, including clinical treatment recommendations, acquire a copy of Den
is Benjamin’s very readable book Mushrooms: Poisons and Panaceas.
The Most Common Mushroom Poisoning Scenarios
An arrogant fool from Muscongus *
Claimed he knew all there was about fungus
I need no advice,
I eat what looks nice.
So now he’s no longer among us.
DIMITRI STANCIOFF
The range of decisions and actions resulting in a victim being evaluated by medical personnel to treat the effects of mushroom poisoning can result from a number of complex personal decisions and behaviors, including misinterpretation of mushroom descriptions, innocence based on naïveté or ignorance, faulty logic, belief in myths regarding mushrooms, and pure unadorned recklessness. To this list, I might add bad luck: the rare combination of the right mushroom, prepared in the right way, but eaten by a person who cannot tolerate the species, such as the honey mushroom. The good news is that most bad experiences can be avoided by following a few basic guidelines set forth in this section.
There are a few common mushroom poisoning scenarios that bear closer examination since the repeated and somewhat predictable mistakes of others can teach the rest of us what not to do. Though the specific examples given below come from my own experiences as a mushroomer and an identification consultant for Poison Control, they also represent common themes mentioned by other consultants and in the literature of mushroom toxicology
The Grazer
The regional Poison Control Center gets a call from a panicked parent, grandparent, or caregiver of a two-year-old child found clutching a mangled mushroom in the yard or, even scarier, with a portion of the mushroom in his or her mouth. It is rarely clear whether the child actually swallowed any portion of a mushroom. Upon questioning by the anxious caregiver, the child becomes equally scared and anxious and gives conflicting information. The child shows no signs of poisoning, but after consulting with a regional Poison Control Center, or often on their own accord, the caregiver decides to take the child to a local hospital for observation, evaluation, and possible treatment. At this point, the poison control staff frequently contacts a consulting mycologist to aid in the identification of the offending mushroom(s). The family is urged to bring examples of the mushroom with them to the hospital for identification.
This example is an amalgamation of many “grazer” calls I have addressed as a volunteer consulting mycologist to the Northern New England Poison Control Center. The most extreme case involved at least nine children who had collected and sampled mushrooms in the woods as part of a group dare. After being tipped off by the most anxious child, terrified parents scoured the woods and brought all the mushrooms they could find to the hospital for examination. When I got the call from the hospital, the medical staff in possession of the mushroom samples initially hoped that I would be able to identify them over the phone. One MD who claimed to know mushrooms said he believed that one of the mushrooms was an amanita, but it was soon evident that the staff had minimal familiarity with mushroom morphology and lacked the vocabulary to describe what they were holding. They also lacked the technology to take and transmit accurate digital images of the mushrooms to me. It quickly became clear that my presence in the same room with the mushrooms was vital if I was to make sense of the diverse collection.
By the time I arrived, frantic parents and caregivers had brought the children and more than a dozen different types of mushrooms to the hospital. Several children had been evaluated by emergency department staff and admitted for observation and more were on their way in to the emergency department. At that point, no child was showing symptoms of distress beyond anxiety that was likely caused by seeing their parents so fearful. Several hours later I knew that there were no deadly amanitas or other seriously toxic mushrooms involved and, of the rest, even if the kids had eaten any of them, the worst-case scenario would be moderate to severe gastrointestinal symptoms. In the end, none of the children involved developed symptoms, though several suffered through the process of ingesting activated charcoal and having gastric lavage performed on them. All, I am certain, were convinced to never eat a wild mushroom again.
In another case tailor-made for the coast of Maine, I received a call directly from an offshore island medical provider after a grandparent found her toddler grandchild in possession of a large yellowish mushroom with whitish patches on the cap and a ring around the stem. From the phone description of free gills and the base of the stem described as swollen, it appeared that we had a likely case of Amanita ingestion, but it was difficult to ascertain which species. It was late June, a time when few Amanita species fruit in Maine and not a time when I normally see any Amanita muscaria var. formosa, a known toxic species (see Chapter 12).
Murphy’s Law peered over the horizon. It was a Friday night and the ferry had already made its last run from island to mainland. Since the child in question was asymptomatic, the situation did not meet the island’s criteria for an emergency ferry run, so there was no way to get the mushroom to the mycologist. The solution came in the shape of a friendly lobsterman who traversed the ten miles of open sea with the mushroom carefully wrapped in wet paper towels and then caught a taxi and delivered the mushroom right to my door as evening ran into night. The mushroom proved to be Amanita flavorubescens, which is, at worst, mildly toxic, and the child remained symptom free under the vigilant eye of family and the island medical staff.
Of the thousands of calls to poison control centers each year regarding mushrooms, about 80 percent involve young children in the grazing stage of life. Before age five, and especially from six months to three years, kids explore the world and objects in their world by putting them in their mouths. When the object is a pretty little mushroom found growing at the edge of Nana’s yard, it becomes every parent’s nightmare. The overwhelming majority of young children evaluated for possible mushroom ingestion never develop symptoms of poisoning, but it is nevertheless prudent to identify the mushroom in question to ensure that the child is adequately treated. Due to their small body mass and developmental stage, young children can be seriously affected by a small amount of mushroom toxin. Some mushrooms that are benign to adults can have a dangerous impact on young children. The compounds psilocybin and psilocin, for example, which are found in several small species of Psilocybin, Panaeolus, and related genera, usually leave the average adult fully recovered from hallucinations and an altered mental state within six hours; in young children, however, the same toxins can spike elevated fever, trigger convulsions, and even lead to death in rare cases.9
As every parent or caregiver of a toddler knows, it is almost impossible to control what they put in their mouths. It is equally impossible to mushroom-proof the average backyard or park. As always, I recommend vigilance and either removing mushrooms from where toddlers might encounter them or removing toddlers from where they might encounter mushrooms. Rest assured that it is extremely rare for a toddler to be seriously sickened by poisonous mushrooms in the United States. If you suspect your toddler has eaten a mushroom, seek a phone consult with your hospital emergency department or poison control center.
The Case of Mistaken Identity
It was almost 1:00 AM, well past my normal witching hour, when the phone rang and jarred me from my sleep. The physician covering our local hospital emergency department was calling about a middle-aged man who was suffering from severe gastrointestinal distress. The man told a story of collecting a bunch of chanterelles, cooking them for dinner, and eating a fair-sized portion. His girlfriend, unsure of the mushrooms, his skills at identification, or both, declined the meal (much to her subsequent relief). Several hours after the meal, he began to feel sick and soon found himself in a painful gastrointestinal drama in which the bathroom played a starring role. He reported eating chanterelles in the past, supplied and cooked by a friend, and said that for a long time he’d been wanting to find his own. When he came upon the dense cluster of orange-yellow mushrooms on the ground at the base of an oak tree, he thought he’d stum
bled on a bonanza of delectable fungi. The color and vase-shape, combined with the gills running down their stems, met his memory of chanterelles. (#7) Back home with his collection, he looked at the description of chanterelles in a popular field guide and made the mushrooms in his hand fit the description in the book.
Unfortunately, for his health and sense of mushrooming competence, the mushrooms that he actually picked and ate that late summer evening were jack o’lantern mushrooms, Omphalotus illudens (see #8 in the color insert). The jack o’lantern grows in dense clusters around the base of hardwood trees, predominately oaks, and as a bioluminescent mushroom (see Chapter 16), glows in the dark with an otherworldly greenish light that emanates from its gills and can be seen in a very dark room. It is a beautiful and fascinating tree parasite, but it is toxic. Jack o’lantern mushrooms cause moderate to severe cramps, vomiting, dizziness, and an overall feeling of weakness and fatigue that can last for many hours or unusually, even days. Onset of the symptoms is generally within two to three hours of the meal. The individual in this case spent the night in the hospital for control of nausea and support of hydration and was released late the following morning.
As these stories show, the case of mistaken identity isn’t always as straightforward as dissonance between a mushroom in hand and the description in a field guide. Especially for new mushroomers, there can be a strong temptation toward magical thinking. The desire to find a great edible can overwhelm rational judgment. If the collector has a strong preconceived notion of what the mushroom’s identity is or, more importantly, what he wants the mushroom to be, his mind will be less open to objectively evaluating the specimen in hand. In the chanterelle case, the victim saw all of the relevant characteristics he wanted to see and ignored or downplayed the features that didn’t fit. Eating wild mushrooms demands that the collector remain objective in seeing and evaluating identification features and not ignore or devalue characteristics that don’t fit. Never eat a mushroom unless you are 100 percent certain of the identification. “When in doubt, throw it out!”
